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Questions for folks running Spec Boxster or tracking their 986 heavily
Hi folks,
I just purchased a 986 for track use. I’m coming from a 997. My plan is to upgrade/modify the car in a way that’ll allow it to be driven in Spec Boxster in the future. Initially, the 986 will be 95% used on the track, 5% for getting to the track and testing my upgrades/repairs. Might go trailer later on as it becomes less street legal and less comfortable to drive on the street.
I have a ton of questions and am seeking advice from Spec Boxster folks or anyone generally who is tracking their 986 heavily. I have done research on many of my questions, but am curious to survey different folks and their opinions, especially folks who heavily track/race.
- In terms of reliability upgrades, my plan is to run a 3rd radiator, the S bigger oil cooler, a 2qt deep sump, an underdrive pulley, and maybe a transmission cooler. I might swap out the water pump too as I’m not sure the last time it was replaced. - Anyone have tips on where I can buy the S oil cooler? - Where should I buy the 3rd radiator kit? I’ve seen it from Pelican, and for about 1/2 the price from tunersmall. Anyone have experience with if these kits are different? - What underdrive pulley do folks recommend? Do folks know where I can get the proper crank bolt? Is this the main/only defense against overheating power steering pump? Or should I do something else too? - Do folks usually run a transmission cooler? And if so, what do you recommend? Also, what transmission fluid are folks running? I am thinking of going Red Line MT90 - Do you have other reliability suggestions? My current thinking is the engine will eventually blow due to oil pressure/starvation issues, and I’ll mostly be treating it as something I’ll have to replace at some point in the future. - What brake pads are folks running/recommend? (On my 997 I’ve run both Pagid Yellows and Ferodo DS3.12). For the 986, I'm thinking of Raybestos ST43. - What brake rotors do folks recommend? I'm thinking of getting the Sebro slotted. - I’ve read various threads on running oil temp and pressure sensors/gauges. Are there any definitive DIYs on this? - Anyone have advice on an exhaust that can pass 90/92db at laguna without laguna pipes? - At the risk of bringing up engine oil preferences, do folks have recommendations here? I’m running Miller’s NT 5w40 in my 997. I’m thinking of running it in the 986 too. Either 5w40, 10w50, or a split of the two. What oil do folks have success with running? I'm also considering Schaeffer's 20w50. - Are low temp thermostats allowed for spec Boxster? - Generally, any other advice is greatly appreciated.
Thanks for the link. I’ve started reading your thread and am enjoying it, but will have to continue to read the rest later.
I’m excited for the journey, even if it might cost me a bit more in the end.
Few quick questions:
- is the main motivation for stripping wiring just to shed weight?
- did you end up replacing all 4 wheel bearings? I have 2 that are bad. But am debating if it’s worth replacing all 4 or just the bad ones.
- do you have a rec for engine oil? Debating what to get now. A lot of other stuff needed to get me DE event #1 is already on the way.
I bought my '98 Boxster brand new in 1998. I discovered HPDE and tracked it more and more heavily while still a daily driver. Then I eventually converted it into its current SPB form. Drove it to the track for as long as it was street legal. Once the catalytic converters came off it was not smoggable and therefore not registerable; also once the roll cage goes in and the airbags come out, most would say it's unsafe to drive (well, unsafe to crash) with your bare un-helmeted skull. Once it's an SPB and you are racing it... trailering becomes pretty much necessary, because you will eventually find yourself at the end of the weekend with a vehicle that cannot be driven all the way home for whatever reason; better if you can limp it onto the trailer and then into your garage.
Removing unneeded wiring is indeed just for weight, although the simplification and cleanliness is nice, too. I have not done any of that and there's a giant roll of unused wires under the passenger side dashboard.
You don't need to replace wheel bearings preventatively, but they are a wear item. My experience racing a fairly full PCA Club Racing schedule is roughly 1 out 4 wheel bearings going bad per season, give or take. When I had all the shocks out for rebuild a few years ago, I proactively replaced all 4 wheel bearings, and put 2 new bearings into a pair of spare wheel carriers I picked up on eBay. (You can pretty easily swap in a carrier at the track if you have a bad wheel bearing, which is not the case for a wheel bearing, without special tools.)
It was kind of fun to strip the car down myself, sort of therapeutic for me at the time.
Miscellaneous responses:
- Oil: whatever works. Had used Mobil 1, then LiquiMoly, then Millers. All good. I'd stick with those. I was at one point advised to use 10w-60 to help an old engine, and stuck with it after a rebuild, but later was told that 60 is ridiculously heavy and to use 40.
- I installed the center radiator, S oil cooler, and the RSS underdrive pulley. The car keeps cool enough. I think the UD pulley is key to keeping the power steering pump happy. It was fairly problematic as a frequent track car / daily driver until I did that.
- I do not think that oil starvation is an issue.
- Very few SPBs have transmission coolers installed. But it can't hurt. The transmissions are definitely a weak spot on these cars when raced. However, I also think (fingers crossed, patting myself on the back) that being nice to the transmission goes a long way. You can speed shift and gain half a second a lap, and buy three transmissions a year, too. If there's a tight corner that's a toss-up between 2nd gear and 3rd gear, stay in 3rd because it's two fewer shifts to screw up, and is easier on the transmission. I use Mobil Delvac 75w90 transmission fluid.
- Brake pads: whatever works. Pagid are very commonly used (black/yellow/red combinations by preference; start with yellow front and rear if no other input). One friend likes Porterfield, or is it Performance Friction?- Brake discs: cheap is good. They should last a long time. Slotted or plain, definitely not drilled. Sebros seem fine.
- To pass 90/92db sound at Laguna Seca (I've done it), just keep the stock exhaust on hand! It's 87db. (And ideally, design your race exhaust to allow swapping them as easily as possible.) I don't know what kind of race exhaust could have extra optional muffling easily tacked on to be that quiet. Use your normal race exhaust elsewhere, or on the 103db Laguna days when PCA Club Racing is there.
- Pretty sure that any thermostat is OK. I don't know that it really makes any difference. I haven't bothered changing it.
You're local -- you should meet the local SPB folks. Good people, always helping each other out with car stuff.
This is Bruce from BRracing in Los Gatos and Campbell (South Bay Area), fairly close to you.
We have built and support over 20 Spec Boxsters.
We have customers who have gone the same route as you, building and developing the car from a street car to a full SPB car.
We also have lots of customers who have bought built SPB, and chosen to upgrade them.
We also have a program for PCA SPB members where we sell parts at discounts if they run our window banner.
Here is CA, we have never seen the need for the tranny cooler, or an Accusump system.
2L deep oil pan is our preference.
3rd radiator is a must.
You should plan on having at least 2 sets of wheels.
We have run both the MCS coil-overs and the Bilstein PSS9 coil-overs, not a big difference in our view between the two.
We recommend wheel bearings every 2 years if the car is being run at over 8 events a year, or more than 16 track days a year.
Brake rotors - most run the Sebro slotted
Brake Pads - most run a combination of Pagid pads
Wiring harness - there are a couple of pieces here. Both getting rid of weight, dealing w the "immobilizer", and converting the car at some point to a push button start vs a key start
Engine reliability - we have current customers who are on their 5th year of racing and have never had to replace or rebuild the engine...the engines are very reliable
You didn't mention it - but you need to plan ahead and incorporate a dash and data...this will be critical to your driver development, and managing the car
Exhausts - there are lots of options for exhaust, and you can see all sorts of different designs....but the easiest solution is to get an exhaust from Vali Motorports in Los Angeles, and get the Laguna option (it's an add on that will allow you to make sound)
Let us know how we can help.
You can email us at brracing@gmail.com, or call us at 408-356-1515
I'd have a look at XP9 oil or the thicker version, XP6. Made by driven.
Buy the Behr S oil cooler...cheaper than in porsche box
Replace all the wheel bearings, but pack the new ones with good Redline CV2 grease.
Change tranny oil every 3 events. I run the porsche stuff, but have also run redline and delvac, no major change
I'd consider the CSF center radiator. Not much more expensive than stock.
Speaking of radiators....remove (or delete) the a/c condensors and clean the factory rads
Deep sump has not proven to be very useful for me as I have all kinds of pressure drops. May have improved them a bit, but still quite scary
Oil pressure and temp gauges. Oil pressure, simply remove stock pressure switch, install VDO sensor and run the wires to a gauge. Oil temp goes on the opposite side head next to airbox. There is a port plug that gets removed and the sensor threads in there.
Convert the top to manual use. I resisted this forever and I'm not sure why. In manual mode, the top operation is a breeze and you can save some weight there.
AOS....get a fresh porsche one and run your oil level a bit lower. I did not do this and managed to damage my engine in my first event.
Great responses above from very knowledgeable people. I took the exact route your planning four years ago and it was a great way to go as I knew I wanted to still drive it to the track, do the work myself gradually and knew it would be a number of more years until I felt I would be ready for club racing. Can it be cheaper to buy a used ready to race car? Yes but you've already picked your path and if you enjoy wrenching as I do it will be a very gratifying experience.
Since you're already sure of it's fate and not trying to have a comfortable street legal track car which is a compromise, strip everything out of the interior except a few key things if you'll be driving it to the track in unknown weather. If you dont have a hard top pull the soft top's transmissions as they weigh a lot, keep the power windows, wiper motors, wiper fluid tank, HVAC, e-brake, airbags are a personal choice but I pulled all of mine. Different States and inspection shops/garages may limit what you can and cant get away with.
All of the mechanical to do "musts" to build a SPB are well documented and or dictated, people like BR Racing can effortless guide you but since your not racing it right off the bat you need to decide what's most important to you first if it's going to be a gradual build that you track along its transformation. All these things take time and money and there's usually a shortage of one of them. The priorities I followed were 1st safety, a full cage will come later for me but I installed a BK roll bar extension, a halo seat, harnesses and Stable Energies built a custom harness bar that bolts to the factory roll bar and puts your shoulder belts at the exact right height. You could also get a Safety Devices cage for it but only install the roll bar section of it now while you're still street driving it to the track.
Second was reliability. My car was a 98 with 55K miles on it and had already had a dual row LN IMS installed, I immediately replaced all the rubber brake lines, the water pump, low temp thermostat, a couple of the big hoses, coolant tank cap, plugs, spark plug tubes that were leaking, all fluids, belts, idler pulleys, RSS 4" under drive pulley, engine mount -Wevo semi solid. The original wheel bearings lasted me 30 track days until I had to replace 3 of them, repacked with Redline. The second season I did a new AOS, center radiator, larger S model Behr oil cooler and oil temp gauge. I have not done a deep sump yet as Im only running 200TW tires for now, the day I go to Toyo RR I'll put one in if not sooner.
Is the 22 year old stock suspension adequate for track use at first? You can do it but it's not fun. First season I installed PSS9 (with the springs it comes with), rear Tarett toe links to get proper alignment from the now lowered car, dont go to SPB legal full lowered level if you're street driving, some experts say not to fully slam it even for full race. Get a good shop to corner balance/align. I kept the stock swaybars and links first season and then went to Tarrett GT3 front bar with extended links in front, stock bar in rear with Tarett links, GT3 front lower control arms to get proper camber, or while not SPB legal for half the price you could go with Elephant camber plates and get up to -3.2. I went with 8.5" wheels all the way around but first season with 235's in front, car handled perfectly neutral and then went 255 all the way around when I gained the adjustability of the GT3 bar.
That's my rant but to answer your specific questions that I missed and others have answered as well:
Oil cooler -Behr "S" cooler
Center Radiator: I bought mine used on eBay along with the air duct and bought new plumbing from Pelican. It's not a plug and play deal when cobbling it together. Pedros website offers some good instruction.
Underdrive pulley: Mine was a 4" from RSS and I got the new bolt from Pelican. 5mm shorter belt -Continental 6K x 2110 (AC still installed)
Transmission: I dont run a cooler, not to say it cant hurt. I change my trans fluid every season and use the "special" porsche/shell stuff that Sunset bottles from big drums.
Brake Pads: They're a number of great options. I've always run ST-43's that Porterfield custom cuts for 986, tons of power and last forever. My fronts went 25 days and my rears are on 40 days with over 50% left. Sebro slotted work well for me.
Oil Sensors: I'll have to find the diy links that I followed and send them later along with part numbers
Exhaust: I've been able to pass Limerock's 87db with this set up, it may partially be because one of the places they test from im in 4th at 4000rpm. I've read that at Laguna Seca nothing but a stock exhaust will work on a 986 but I have no idea if that's accurate. This option might not work in CA. if they physically check to see if the cats are there. I installed cheap eBay Circuit Werks mid pipes with resonators and a "Top Speed" muffler. This set up retains the stock S connecting pipes. I then stuffed the correct diameter sized short 6" motorcycle baffle wrapped in glass in to one of the S pipe/muffler junctions. This eliminated any drone for highway driving and knocked a few decibels off too. At first the set up was super loud when testing and was hitting 98db. After a few hundred miles the system coked up and quieted itself a ton. This was a very cheap under $500 option and has worked great for me and was a big weight savings over stock. The mid-pipes have 2 sets of sensor bungs, the ones just past the resonators i plugged and zip tied the sensors up in to the body work. I get no check engine light except on my 4 hour drive to Watkins Glen where I'll clear the code with my bluetooth OBD reader. I've always passed NY inspection via OBD but I think your laws are different.
Oil: I started with Mobil 1 5w-50 but now only use Motul 300V, they dont make an exact 5-50 but you can mix their 0w-40 with their 20w-60 at a 55/45% ratio to land at 5-50. It's expensive but I test all my oil with Blackstone and the TBN is still very strong after 10 hours of track time with good metal levels. Nick from Motul posts every now and then and these are his recommendations re: 300V. "For mixed driving (track and street), being more conservative will be a good practice- I'd recommend draining at 3,000 miles and see what the UOA looks like." "The typical street-driving drain interval is ~3,000 miles and a 90% track and 10% street mix would be closer to 750 to 1,000 miles, depending on engine temps, length of sessions, etc." -You'll find in a 986 that you'll be full gas nearly everywhere screaming at redline, a really good oil cant hurt.
Hope this info helps in transforming the car slowly in to a SPB. Feel free to DM if you want some helpful photos or links.
I bought my '98 Boxster brand new in 1998. I discovered HPDE and tracked it more and more heavily while still a daily driver. Then I eventually converted it into its current SPB form. Drove it to the track for as long as it was street legal. Once the catalytic converters came off it was not smoggable and therefore not registerable; also once the roll cage goes in and the airbags come out, most would say it's unsafe to drive (well, unsafe to crash) with your bare un-helmeted skull. Once it's an SPB and you are racing it... trailering becomes pretty much necessary, because you will eventually find yourself at the end of the weekend with a vehicle that cannot be driven all the way home for whatever reason; better if you can limp it onto the trailer and then into your garage.
Removing unneeded wiring is indeed just for weight, although the simplification and cleanliness is nice, too. I have not done any of that and there's a giant roll of unused wires under the passenger side dashboard.
You don't need to replace wheel bearings preventatively, but they are a wear item. My experience racing a fairly full PCA Club Racing schedule is roughly 1 out 4 wheel bearings going bad per season, give or take. When I had all the shocks out for rebuild a few years ago, I proactively replaced all 4 wheel bearings, and put 2 new bearings into a pair of spare wheel carriers I picked up on eBay. (You can pretty easily swap in a carrier at the track if you have a bad wheel bearing, which is not the case for a wheel bearing, without special tools.)
It was kind of fun to strip the car down myself, sort of therapeutic for me at the time.
Miscellaneous responses:
- Oil: whatever works. Had used Mobil 1, then LiquiMoly, then Millers. All good. I'd stick with those. I was at one point advised to use 10w-60 to help an old engine, and stuck with it after a rebuild, but later was told that 60 is ridiculously heavy and to use 40.
- I installed the center radiator, S oil cooler, and the RSS underdrive pulley. The car keeps cool enough. I think the UD pulley is key to keeping the power steering pump happy. It was fairly problematic as a frequent track car / daily driver until I did that.
- I do not think that oil starvation is an issue.
- Very few SPBs have transmission coolers installed. But it can't hurt. The transmissions are definitely a weak spot on these cars when raced. However, I also think (fingers crossed, patting myself on the back) that being nice to the transmission goes a long way. You can speed shift and gain half a second a lap, and buy three transmissions a year, too. If there's a tight corner that's a toss-up between 2nd gear and 3rd gear, stay in 3rd because it's two fewer shifts to screw up, and is easier on the transmission. I use Mobil Delvac 75w90 transmission fluid.
- Brake pads: whatever works. Pagid are very commonly used (black/yellow/red combinations by preference; start with yellow front and rear if no other input). One friend likes Porterfield, or is it Performance Friction?- Brake discs: cheap is good. They should last a long time. Slotted or plain, definitely not drilled. Sebros seem fine.
- To pass 90/92db sound at Laguna Seca (I've done it), just keep the stock exhaust on hand! It's 87db. (And ideally, design your race exhaust to allow swapping them as easily as possible.) I don't know what kind of race exhaust could have extra optional muffling easily tacked on to be that quiet. Use your normal race exhaust elsewhere, or on the 103db Laguna days when PCA Club Racing is there.
- Pretty sure that any thermostat is OK. I don't know that it really makes any difference. I haven't bothered changing it.
You're local -- you should meet the local SPB folks. Good people, always helping each other out with car stuff.
Have fun!
It was a pretty car for a long time...
Removing all the comfortable parts...
Fun garage work?
Rennsport Reunion VI
Your car looks awesome!
Thanks for the heads up on the wheel bearings. Maybe I'll look into some spare wheel carriers as well. I'm still trying to diagnose if my issue is a wheel bearing. Now that the car is on jack stands, I can't quite feel what I did while pushing around on the wheel while it was loaded on the ground. I'll post a video later tonight/tomorrow to get some advice from y'all on if it's the bearing. The sound my car is making in the video might be easy to diagnose for someone who's dealt with a similar issue.
- Is there a big difference between the Tarett under drive pulley vs the RSS kit?
- Thanks for the info on the transmission cooler. I'll probably start life off without it (and cross my fingers as well), and try to take it easy on the transmission.
- I went with the Raybestos ST43 that are custom cut from Porterfield, and the Sebro slotted (I've had good experiences with the Sebro's in my 997).
I'd love to meet local SPB folks. What's the best way to do that? Just go out to PCA events?
This is Bruce from BRracing in Los Gatos and Campbell (South Bay Area), fairly close to you.
We have built and support over 20 Spec Boxsters.
We have customers who have gone the same route as you, building and developing the car from a street car to a full SPB car.
We also have lots of customers who have bought built SPB, and chosen to upgrade them.
We also have a program for PCA SPB members where we sell parts at discounts if they run our window banner.
Here is CA, we have never seen the need for the tranny cooler, or an Accusump system.
2L deep oil pan is our preference.
3rd radiator is a must.
You should plan on having at least 2 sets of wheels.
We have run both the MCS coil-overs and the Bilstein PSS9 coil-overs, not a big difference in our view between the two.
We recommend wheel bearings every 2 years if the car is being run at over 8 events a year, or more than 16 track days a year.
Brake rotors - most run the Sebro slotted
Brake Pads - most run a combination of Pagid pads
Wiring harness - there are a couple of pieces here. Both getting rid of weight, dealing w the "immobilizer", and converting the car at some point to a push button start vs a key start
Engine reliability - we have current customers who are on their 5th year of racing and have never had to replace or rebuild the engine...the engines are very reliable
You didn't mention it - but you need to plan ahead and incorporate a dash and data...this will be critical to your driver development, and managing the car
Exhausts - there are lots of options for exhaust, and you can see all sorts of different designs....but the easiest solution is to get an exhaust from Vali Motorports in Los Angeles, and get the Laguna option (it's an add on that will allow you to make sound)
Let us know how we can help.
You can email us at brracing@gmail.com, or call us at 408-356-1515
Bruce, thanks for your reply and advice/guidance. You actually helped me out a lot as well as I built out the suspension on my 997 giving me a lot of advice there.
A bit of more info for folks here is that one of my main reasons moving to the 986 is:
- I wanted something a bit lighter and slower than the 997. I think having a slower car will provide a better platform for becoming a better driver
- I wanted something less expensive if catastrophe hits (concrete wall, blown engine, etc)
Thanks for your tips:
- I plan to put the deep sump in. I have the 2qt LN kit in my 997. I'll purchase it again for the 986
- I will get a 3rd radiator for the 986 too.
- Thanks. I'm actually working on procuring a second set of wheels now. Should I run the 8.5" wheels in the front and the back, even if I run staggered tires?
- Thanks for the heads up. What tends to b the failure mechanism of the wheel bearings going bad on 986s?
- What's the "dealing with the immobilizer" part. In ace37's build thread, it also appeared he had some issues with the immobilizer. What should I be doing here, and what's the issue?
- That's great to here. I sure hope my engine lasts a long time, but I'm also mentally prepared to replace it if (when?) it blows
- I'm currently running an Aim Solo 2 DL. I want to get oil temp and oil pressure sensors as well. Hopefully I'll be able to log these to the Solo 2 DL, but if not, might need to upgrade to a different Aim device. Is this the kind of logging you had in mind, or something else?
- Thanks for the tip on the exhaust. I'll check it out
My hope with the car is to do as much of the build as I can on my own, but plan to come to you guys for some of the bigger tasks that I likely can't handle in my garage (something like an engine replacement).
I'd have a look at XP9 oil or the thicker version, XP6. Made by driven.
Buy the Behr S oil cooler...cheaper than in porsche box
Replace all the wheel bearings, but pack the new ones with good Redline CV2 grease.
Change tranny oil every 3 events. I run the porsche stuff, but have also run redline and delvac, no major change
I'd consider the CSF center radiator. Not much more expensive than stock.
Speaking of radiators....remove (or delete) the a/c condensors and clean the factory rads
Deep sump has not proven to be very useful for me as I have all kinds of pressure drops. May have improved them a bit, but still quite scary
Oil pressure and temp gauges. Oil pressure, simply remove stock pressure switch, install VDO sensor and run the wires to a gauge. Oil temp goes on the opposite side head next to airbox. There is a port plug that gets removed and the sensor threads in there.
Convert the top to manual use. I resisted this forever and I'm not sure why. In manual mode, the top operation is a breeze and you can save some weight there.
AOS....get a fresh porsche one and run your oil level a bit lower. I did not do this and managed to damage my engine in my first event.
- Thanks for the tips. My experience with the 2qt sump in my 997 was similar. I still get pressure drops, but they are less severe. Still scary.
- Good idea on converting to manual use top. Do you know any DIYs on this? (I haven't googled around yet). I'll probably do this until I move to a fiberglass top.
- What level are you running your oil percentage from min to max? I guess another question, do folks trust the electronic or manual dipstick more?
Great responses above from very knowledgeable people. I took the exact route your planning four years ago and it was a great way to go as I knew I wanted to still drive it to the track, do the work myself gradually and knew it would be a number of more years until I felt I would be ready for club racing. Can it be cheaper to buy a used ready to race car? Yes but you've already picked your path and if you enjoy wrenching as I do it will be a very gratifying experience.
Since you're already sure of it's fate and not trying to have a comfortable street legal track car which is a compromise, strip everything out of the interior except a few key things if you'll be driving it to the track in unknown weather. If you dont have a hard top pull the soft top's transmissions as they weigh a lot, keep the power windows, wiper motors, wiper fluid tank, HVAC, e-brake, airbags are a personal choice but I pulled all of mine. Different States and inspection shops/garages may limit what you can and cant get away with.
All of the mechanical to do "musts" to build a SPB are well documented and or dictated, people like BR Racing can effortless guide you but since your not racing it right off the bat you need to decide what's most important to you first if it's going to be a gradual build that you track along its transformation. All these things take time and money and there's usually a shortage of one of them. The priorities I followed were 1st safety, a full cage will come later for me but I installed a BK roll bar extension, a halo seat, harnesses and Stable Energies built a custom harness bar that bolts to the factory roll bar and puts your shoulder belts at the exact right height. You could also get a Safety Devices cage for it but only install the roll bar section of it now while you're still street driving it to the track.
Second was reliability. My car was a 98 with 55K miles on it and had already had a dual row LN IMS installed, I immediately replaced all the rubber brake lines, the water pump, low temp thermostat, a couple of the big hoses, coolant tank cap, plugs, spark plug tubes that were leaking, all fluids, belts, idler pulleys, RSS 4" under drive pulley, engine mount -Wevo semi solid. The original wheel bearings lasted me 30 track days until I had to replace 3 of them, repacked with Redline. The second season I did a new AOS, center radiator, larger S model Behr oil cooler and oil temp gauge. I have not done a deep sump yet as Im only running 200TW tires for now, the day I go to Toyo RR I'll put one in if not sooner.
Is the 22 year old stock suspension adequate for track use at first? You can do it but it's not fun. First season I installed PSS9 (with the springs it comes with), rear Tarett toe links to get proper alignment from the now lowered car, dont go to SPB legal full lowered level if you're street driving, some experts say not to fully slam it even for full race. Get a good shop to corner balance/align. I kept the stock swaybars and links first season and then went to Tarrett GT3 front bar with extended links in front, stock bar in rear with Tarett links, GT3 front lower control arms to get proper camber, or while not SPB legal for half the price you could go with Elephant camber plates and get up to -3.2. I went with 8.5" wheels all the way around but first season with 235's in front, car handled perfectly neutral and then went 255 all the way around when I gained the adjustability of the GT3 bar.
That's my rant but to answer your specific questions that I missed and others have answered as well:
Oil cooler -Behr "S" cooler
Center Radiator: I bought mine used on eBay along with the air duct and bought new plumbing from Pelican. It's not a plug and play deal when cobbling it together. Pedros website offers some good instruction.
Underdrive pulley: Mine was a 4" from RSS and I got the new bolt from Pelican. 5mm shorter belt -Continental 6K x 2110 (AC still installed)
Transmission: I dont run a cooler, not to say it cant hurt. I change my trans fluid every season and use the "special" porsche/shell stuff that Sunset bottles from big drums.
Brake Pads: They're a number of great options. I've always run ST-43's that Porterfield custom cuts for 986, tons of power and last forever. My fronts went 25 days and my rears are on 40 days with over 50% left. Sebro slotted work well for me.
Oil Sensors: I'll have to find the diy links that I followed and send them later along with part numbers
Exhaust: I've been able to pass Limerock's 87db with this set up, it may partially be because one of the places they test from im in 4th at 4000rpm. I've read that at Laguna Seca nothing but a stock exhaust will work on a 986 but I have no idea if that's accurate. This option might not work in CA. if they physically check to see if the cats are there. I installed cheap eBay Circuit Werks mid pipes with resonators and a "Top Speed" muffler. This set up retains the stock S connecting pipes. I then stuffed the correct diameter sized short 6" motorcycle baffle wrapped in glass in to one of the S pipe/muffler junctions. This eliminated any drone for highway driving and knocked a few decibels off too. At first the set up was super loud when testing and was hitting 98db. After a few hundred miles the system coked up and quieted itself a ton. This was a very cheap under $500 option and has worked great for me and was a big weight savings over stock. The mid-pipes have 2 sets of sensor bungs, the ones just past the resonators i plugged and zip tied the sensors up in to the body work. I get no check engine light except on my 4 hour drive to Watkins Glen where I'll clear the code with my bluetooth OBD reader. I've always passed NY inspection via OBD but I think your laws are different.
Oil: I started with Mobil 1 5w-50 but now only use Motul 300V, they dont make an exact 5-50 but you can mix their 0w-40 with their 20w-60 at a 55/45% ratio to land at 5-50. It's expensive but I test all my oil with Blackstone and the TBN is still very strong after 10 hours of track time with good metal levels. Nick from Motul posts every now and then and these are his recommendations re: 300V. "For mixed driving (track and street), being more conservative will be a good practice- I'd recommend draining at 3,000 miles and see what the UOA looks like." "The typical street-driving drain interval is ~3,000 miles and a 90% track and 10% street mix would be closer to 750 to 1,000 miles, depending on engine temps, length of sessions, etc." -You'll find in a 986 that you'll be full gas nearly everywhere screaming at redline, a really good oil cant hurt.
Hope this info helps in transforming the car slowly in to a SPB. Feel free to DM if you want some helpful photos or links.
- Thanks for the tips on what weight to shed. I'll probably follow your advice and keep a few of the things until I start to trailer, like you suggest
- I already ordered the BK rollbar extension. I think I'll go with some OMP WCRs for the seat to begin with.
- I found this on stable energies website, but it appears to be a rollbar. https://www.stableenergies.com/Roll-...o/SD%2DP66RWB/. Maybe I should do it instead of the BK extension. Do you have a link to the harness bar you're talking about?
- Good list of stuff to replace. I'm starting with all fluid flushes. Gonna do an under drive pulley. How does RSS compare to Tarett?
- What's the main motivation for the SS brake lines?
- Would you recommend running the 8.5" wheels all around even if I run staggered tires? Or if I run staggered tires, should I run staggered wheels too? The 7" front wheels seem a bit small for 235s, so I've been wondering if I should go square wheels all around irrespective of square of staggered tires.
- That's some nice longevity on the ST43s. I'm excited to give them a go. I've tried Ferodo and Pagid's in my 997, so it'll be nice to experience a 3rd compound.
- If you can find the DIY on the oil temp/pressure sensor, that'd be much appreciated.
- Thanks for the oil advice, change interval seems like a good start. I'll also test with Blackstone labs as I dial in longevity of the oil. I'm debating between Motul (and mixing like you suggest), Millers, and Schaeffers 20w50. Anyone have experience on the Schaeffers?
Thanks for the link. I’ve started reading your thread and am enjoying it, but will have to continue to read the rest later.
I’m excited for the journey, even if it might cost me a bit more in the end.
Few quick questions:
- is the main motivation for stripping wiring just to shed weight?
- did you end up replacing all 4 wheel bearings? I have 2 that are bad. But am debating if it’s worth replacing all 4 or just the bad ones.
- do you have a rec for engine oil? Debating what to get now. A lot of other stuff needed to get me DE event #1 is already on the way.
For wiring there are two big benefits. One is simplicity, less junk in your stripped car. Mostly when doing the wiring you’ve removed a part and the dead wiring is now still running all around there in your car. And all the carpet and trim is gone so it’s kind of everywhere. It’s ugly and it flops around. The other is weight. It’s not a lot of weight, but it’s not doing anything besides slowing you down and getting in the way so it seems like a race car shouldn’t have it.
I haven’t replaced any wheel bearings yet. I’ve balanced my tires, even Toyo RRs, and I don’t have a lot of miles of track time yet. I suspect high speeds with unbalanced tires is what kills them in race cars. Wear can be proportionate to load to the fourth power (it’s rarely so simple but that’s a classic engineering calculation/result), so my intuition says a little balance issue carried at high speeds for long periods of time might be something that destroys bearings. (It’s been a while since I did anything with them, but the company SKF has a bunch of publications that would be informative.)
For oil no I don’t have a recommendation.
I did an oil cooler instead of a third radiator and it seems to do the job well. I have an accusump but probably wouldn’t bother if I were doing it again. I put it in right after my engine went as I wasn’t sure if our track was unusually hard on these motors. Other SPBs have since shown up and put over 100 hours on motors without issues so apparently it was just time for that motor to die.
Originally Posted by saamyjoon
Bruce, thanks for your reply and advice/guidance. You actually helped me out a lot as well as I built out the suspension on my 997 giving me a lot of advice there.
A bit of more info for folks here is that one of my main reasons moving to the 986 is:
- I wanted something a bit lighter and slower than the 997. I think having a slower car will provide a better platform for becoming a better driver
- I wanted something less expensive if catastrophe hits (concrete wall, blown engine, etc)
Thanks for your tips:
- I plan to put the deep sump in. I have the 2qt LN kit in my 997. I'll purchase it again for the 986
- I will get a 3rd radiator for the 986 too.
- Thanks. I'm actually working on procuring a second set of wheels now. Should I run the 8.5" wheels in the front and the back, even if I run staggered tires?
- Thanks for the heads up. What tends to b the failure mechanism of the wheel bearings going bad on 986s?
- What's the "dealing with the immobilizer" part. In ace37's build thread, it also appeared he had some issues with the immobilizer. What should I be doing here, and what's the issue?
- That's great to here. I sure hope my engine lasts a long time, but I'm also mentally prepared to replace it if (when?) it blows
- I'm currently running an Aim Solo 2 DL. I want to get oil temp and oil pressure sensors as well. Hopefully I'll be able to log these to the Solo 2 DL, but if not, might need to upgrade to a different Aim device. Is this the kind of logging you had in mind, or something else?
- Thanks for the tip on the exhaust. I'll check it out
My hope with the car is to do as much of the build as I can on my own, but plan to come to you guys for some of the bigger tasks that I likely can't handle in my garage (something like an engine replacement).
The immobilizer is not anything crazy but it’s (by design) hard to troubleshoot if you make it fail by cutting a wire that you shouldn’t cut. I get too aggressive with the snips. So do a lot of other folks. That’s the issue. If you have the time and disposition to be patient with the wiring and check everything twice or three times you’ll be fine. I have neither so I made mistakes and now I’ll pay a shop to fix the last of them.
I had time before when I started the build. Now I have less time and more available money so more of the work is done at the shop.
I have the Raybestos pads and they’ve been great. SRF and Endless are both good fluids.
My exhaust was custom by a local shop. They did just fine. I wanted very short mufflers on the car. Mine won’t pass laguna but they’re pretty light, sound great, and I don’t need earplugs. For a nationals level car I’d go with mandrel bent straight pipes.
10-29-2020, 08:02 PM
Questions for folks running Spec Boxster or tracking their 986 heavily
