991 Turbo track car
11-12-2020, 01:01 AM
#691
The problem with turbochargers is that big turbos do not work well at slow engine speeds, while small turbos are fast to spool but run out of steam pretty quick. A turbocharger equipped with Variable Turbine Geometry has little movable vanes which can direct exhaust flow onto the turbine blades. The angle of the vanes vary throughout the engine RPM range to optimizing the turbine behavior. This essentially allowed Porsche to generate tons of power, fixed low end turbo lag / boost and keep a fairly small turbo. As we start increasing the boost, the turbos will start spooling quicker thus the reason that we suddenly start generating really high torque at low RPM ranges. Your stock 991.1 Turbo has smaller turbos than a 2RS. Yet on stage 3 you can push these little guys close to the same HP as the 2RS. Therefore we start overheating them on track use. So the next step is to go to a larger VTG. This works well like you see in a stock 2RS. With that said, I have seen folks pushing up to 750WHP on those same turbos. So similarly to pushing the stock turbos too hard the same thing will happen then. This is where a non vtg turbo will really be helpful. Specially if one intends to use it for track use whereby low RPM turbo lag is not really important.
In summary, we can push these car's engine pretty hard and will perform extremely well at the drag strip and the street. For track use, you don't want to push the turbos as hard as you will end up actually loosing more power throughout the session etc. Again, it all comes down to goals. Like you very well said, your fastest time was actually done while your car was having boost issues. These cars are really fast already, dealing with their weight, handling and driving technique will yield you a lot more lap time than engine performance. I should remind my self of this every time i add something new
As you start getting faster you will get hungrier for speed so its unavoidable!
BTW thanks for keeping posting videos of the progress. Its always exiting seeing folks track these cars and have as much fun as we all do. Now you need to add some good tire combo and keep ripping it out there. I bet you will be in the 19's just by changing tires.
In summary, we can push these car's engine pretty hard and will perform extremely well at the drag strip and the street. For track use, you don't want to push the turbos as hard as you will end up actually loosing more power throughout the session etc. Again, it all comes down to goals. Like you very well said, your fastest time was actually done while your car was having boost issues. These cars are really fast already, dealing with their weight, handling and driving technique will yield you a lot more lap time than engine performance. I should remind my self of this every time i add something new
As you start getting faster you will get hungrier for speed so its unavoidable!BTW thanks for keeping posting videos of the progress. Its always exiting seeing folks track these cars and have as much fun as we all do. Now you need to add some good tire combo and keep ripping it out there. I bet you will be in the 19's just by changing tires.
You bring up a good point about weight as that's the enemy of everything (corner/straight line speed, fuel consumption, handling, etc). These things are absolute porkers! I can be toe-to-toe with a cup car on the straights but the moment we get into a corner, it seemingly leapfrogs from me and while those cup car drivers are leaps and bounds beyond me in skill, the weight difference is absolutely apparent (granted I'm still on street tires). I've removed my rear seats and replaced it with a GT3 rear seat delete. The full kline inconel system should also help shave a few pounds too. My GT2 carbon buckets shaved off a little bit of weight too but I can't think of anything else reasonable to remove that would help me more (the glass roof doesn't help) without turning it into an all out track car (candidly, I've got track miles than street miles at this point).
And yes, I'm happy to share the videos with the likeminded folks here. There's not a lot of Turbos' on track compared to GT3's so for me, this thread in particular is GOLD as there's so much information on here. Nothing against the other 99% of threads on this forum - cars and coffee, drag racing and 60-130 times just don't interest me so I've found a home here with you guys.
Speaking of tires - that's my next big decision for next year. The local tire shop who caters to all of the grassroots and club racers recommended R888R's as they're cheaper than RE-71's which don't come in my size and supposedly Cup 2's are expensive and fall off a cliff after the first handful of heat cycles. I'm limited on tire choices with the 20's. Hopefully I can get down to the 19's with a stickier tire and just more seat time. I've been eyeballing TPC's PFC kit but $14k on brakes might get me divorced especially with the arrival of our 2nd son 5 weeks ago! Kids ruin everything!
11-12-2020, 01:59 AM
#692
Sam has been great to work with and his service is second to none. If you do decide to get out on track, pick up upgraded pads and flush out your brake fluid as the faster the car, the most strain it'll put on those parts. Careful not to catch the bug! I've logged 32 days on track this year even with a pandemic. There's no greater investment you can make than seat time as the driver is what matters most; not the car.
Thanks for the explanation. I come from the world of high revving naturally aspirated cars so this Turbo thing is somewhat new to me. I'm appreciating more and more what these cars are capable of as I certainly don't need more power but it is fun!
You bring up a good point about weight as that's the enemy of everything (corner/straight line speed, fuel consumption, handling, etc). These things are absolute porkers! I can be toe-to-toe with a cup car on the straights but the moment we get into a corner, it seemingly leapfrogs from me and while those cup car drivers are leaps and bounds beyond me in skill, the weight difference is absolutely apparent (granted I'm still on street tires). I've removed my rear seats and replaced it with a GT3 rear seat delete. The full kline inconel system should also help shave a few pounds too. My GT2 carbon buckets shaved off a little bit of weight too but I can't think of anything else reasonable to remove that would help me more (the glass roof doesn't help) without turning it into an all out track car (candidly, I've got track miles than street miles at this point).
And yes, I'm happy to share the videos with the likeminded folks here. There's not a lot of Turbos' on track compared to GT3's so for me, this thread in particular is GOLD as there's so much information on here. Nothing against the other 99% of threads on this forum - cars and coffee, drag racing and 60-130 times just don't interest me so I've found a home here with you guys.
Speaking of tires - that's my next big decision for next year. The local tire shop who caters to all of the grassroots and club racers recommended R888R's as they're cheaper than RE-71's which don't come in my size and supposedly Cup 2's are expensive and fall off a cliff after the first handful of heat cycles. I'm limited on tire choices with the 20's. Hopefully I can get down to the 19's with a stickier tire and just more seat time. I've been eyeballing TPC's PFC kit but $14k on brakes might get me divorced especially with the arrival of our 2nd son 5 weeks ago! Kids ruin everything!
Thanks for the explanation. I come from the world of high revving naturally aspirated cars so this Turbo thing is somewhat new to me. I'm appreciating more and more what these cars are capable of as I certainly don't need more power but it is fun!
You bring up a good point about weight as that's the enemy of everything (corner/straight line speed, fuel consumption, handling, etc). These things are absolute porkers! I can be toe-to-toe with a cup car on the straights but the moment we get into a corner, it seemingly leapfrogs from me and while those cup car drivers are leaps and bounds beyond me in skill, the weight difference is absolutely apparent (granted I'm still on street tires). I've removed my rear seats and replaced it with a GT3 rear seat delete. The full kline inconel system should also help shave a few pounds too. My GT2 carbon buckets shaved off a little bit of weight too but I can't think of anything else reasonable to remove that would help me more (the glass roof doesn't help) without turning it into an all out track car (candidly, I've got track miles than street miles at this point).
And yes, I'm happy to share the videos with the likeminded folks here. There's not a lot of Turbos' on track compared to GT3's so for me, this thread in particular is GOLD as there's so much information on here. Nothing against the other 99% of threads on this forum - cars and coffee, drag racing and 60-130 times just don't interest me so I've found a home here with you guys.
Speaking of tires - that's my next big decision for next year. The local tire shop who caters to all of the grassroots and club racers recommended R888R's as they're cheaper than RE-71's which don't come in my size and supposedly Cup 2's are expensive and fall off a cliff after the first handful of heat cycles. I'm limited on tire choices with the 20's. Hopefully I can get down to the 19's with a stickier tire and just more seat time. I've been eyeballing TPC's PFC kit but $14k on brakes might get me divorced especially with the arrival of our 2nd son 5 weeks ago! Kids ruin everything!
congrats on the new little one, we have a 8 month old born 2 weeks before the country shut down.
totally agree on seat time...true story, my first track day I had a 600 whp C5 Corvette that was lightened up and had $10k worth of suspension work...and I was a heck of canyon carver with it....but I spent the whole day being passed by 150 whp miatas 😂😂😂
Did you get the lighter Lithium battery? That thing is 45 pounds lighter than the factory battery and it’s up high in the car so lightening there also lowers the center of gravity....and...I have the R888R and love them for what it’s worth,
Already have high temp brake fluid in there.
I also have the Carbon ceramic brakes...just assumed there wasn’t a pad upgrade for those and I’d have to switch to steal brakes for that
do you have a pad recommendation for those that you love?
11-12-2020, 03:11 PM
#693
Racer
You bring up a good point about weight as that's the enemy of everything (corner/straight line speed, fuel consumption, handling, etc). These things are absolute porkers! I can be toe-to-toe with a cup car on the straights but the moment we get into a corner, it seemingly leapfrogs from me and while those cup car drivers are leaps and bounds beyond me in skill, the weight difference is absolutely apparent (granted I'm still on street tires). I've removed my rear seats and replaced it with a GT3 rear seat delete. The full kline inconel system should also help shave a few pounds too. My GT2 carbon buckets shaved off a little bit of weight too but I can't think of anything else reasonable to remove that would help me more (the glass roof doesn't help) without turning it into an all out track car (candidly, I've got track miles than street miles at this point).
And yes, I'm happy to share the videos with the likeminded folks here. There's not a lot of Turbos' on track compared to GT3's so for me, this thread in particular is GOLD as there's so much information on here. Nothing against the other 99% of threads on this forum - cars and coffee, drag racing and 60-130 times just don't interest me so I've found a home here with you guys.
Speaking of tires - that's my next big decision for next year. The local tire shop who caters to all of the grassroots and club racers recommended R888R's as they're cheaper than RE-71's which don't come in my size and supposedly Cup 2's are expensive and fall off a cliff after the first handful of heat cycles. I'm limited on tire choices with the 20's. Hopefully I can get down to the 19's with a stickier tire and just more seat time. I've been eyeballing TPC's PFC kit but $14k on brakes might get me divorced especially with the arrival of our 2nd son 5 weeks ago! Kids ruin everything!
And yes, I'm happy to share the videos with the likeminded folks here. There's not a lot of Turbos' on track compared to GT3's so for me, this thread in particular is GOLD as there's so much information on here. Nothing against the other 99% of threads on this forum - cars and coffee, drag racing and 60-130 times just don't interest me so I've found a home here with you guys.
Speaking of tires - that's my next big decision for next year. The local tire shop who caters to all of the grassroots and club racers recommended R888R's as they're cheaper than RE-71's which don't come in my size and supposedly Cup 2's are expensive and fall off a cliff after the first handful of heat cycles. I'm limited on tire choices with the 20's. Hopefully I can get down to the 19's with a stickier tire and just more seat time. I've been eyeballing TPC's PFC kit but $14k on brakes might get me divorced especially with the arrival of our 2nd son 5 weeks ago! Kids ruin everything!
Tires make a big difference. Jumping from the PS4's up will be a very big upgrade. As you step up in tire the drop from the first couple of heat cycles thereafter will get more pronounced. However this doesn't mean the tires are bad just the way the tires compounds are now a days. My personal preferences are as follows
- Cup 2's: good tire, very consistent will last you probably 20 - 25 heat cycles. The first three heat cycles will be its fastest and then from from there. Prices are around. Prices ranging in the mid $400's for 19" tire. They run a little narrower to the Pirelli's
- Trofe R: this is my favorite street tire, i personally found it more consistent than the Cup 2's and a little faster. However, they will last 15 to 20 heat cycles Prices ranging in the $500's for the 19" tire
- Cup R: The first two heat cycles is wicket fast then it will drop and be similar to a trofeo. Similarly life span is shorter than the cup 2 and more in line with the trofeo's R in terms of wear. Tires are really expensive though and not offered on our car sizes.
- Hossier: I did not like this tire at all. It came apart within two days. Likes to be run with a lot more tire pressure sue to its soft wall. Very inconsistent.
- Dunlop Sport Maxx Race 2: Probably the most consistent tire of the three above, but sizes won't work with our cars
- Next step is slicks
- Pirelli DH work extremely well. Max heat cycles will be 10 to 15 at most. They do drop quite a bit after the first three heat cycles but they are extremely consistent thereafter. Even after they drop they will run like a brand new R or maybe even a second quicker on a 2 minute lap.
- brand new this tires will average about $650 - $700.
- You can buy scrubs with 5 heat cycles in them for $125. They will last you at least two days depending on your driving style etc.
- Hankook: They are similar to the Hoosiers in speed, but much more consistent like a Pirelli. Also a lot cheaper. Only issue is that you need to run a smaller front tire
- Pirelli DH work extremely well. Max heat cycles will be 10 to 15 at most. They do drop quite a bit after the first three heat cycles but they are extremely consistent thereafter. Even after they drop they will run like a brand new R or maybe even a second quicker on a 2 minute lap.
Another consideration is if you want a tire that can do wet and dry. The Cup 2 will be the best for this. Given the amount of track time you are doing, you should consider having a consumable tracking list which includes tires, brake pads, rotors etc. You track the brands you have purchase, how long they last, cost etc. It will help you in the future not just track budgets but also be smart about upgrades, bulk purchases etc.
11-13-2020, 12:28 AM
#694
congrats on the new little one, we have a 8 month old born 2 weeks before the country shut down.
totally agree on seat time...true story, my first track day I had a 600 whp C5 Corvette that was lightened up and had $10k worth of suspension work...and I was a heck of canyon carver with it....but I spent the whole day being passed by 150 whp miatas 😂😂😂
Did you get the lighter Lithium battery? That thing is 45 pounds lighter than the factory battery and it’s up high in the car so lightening there also lowers the center of gravity....and...I have the R888R and love them for what it’s worth,
Already have high temp brake fluid in there.
I also have the Carbon ceramic brakes...just assumed there wasn’t a pad upgrade for those and I’d have to switch to steal brakes for that
do you have a pad recommendation for those that you love?
totally agree on seat time...true story, my first track day I had a 600 whp C5 Corvette that was lightened up and had $10k worth of suspension work...and I was a heck of canyon carver with it....but I spent the whole day being passed by 150 whp miatas 😂😂😂
Did you get the lighter Lithium battery? That thing is 45 pounds lighter than the factory battery and it’s up high in the car so lightening there also lowers the center of gravity....and...I have the R888R and love them for what it’s worth,
Already have high temp brake fluid in there.
I also have the Carbon ceramic brakes...just assumed there wasn’t a pad upgrade for those and I’d have to switch to steal brakes for that
do you have a pad recommendation for those that you love?
Thanks and congrats to you too! Wives being pregnant during a pandemic is rough but we can both look back and say that it's the one good thing from this year given all of the commotion. Speaking of Miata's, I had one guy at an event with TrackDaze that had an LS swap in one, as I was heading into turn 10 and he was exiting, by the time my wheels were straight he must have been at the braking zone into 1 already. There's something to be said about those small little Miata's but I'd be scared with that much power and that short wheelbase. I looked at the Lithium batteries but god damn they're expensive!
I'd swap out the ceramics to a set of Girodiscs as the replacement costs for the ceramics are through the roof for a consumable ($8k/rotor?). I ran both the Ferodo DS1.11's and 3.12's and both are great pads but I think I am leaning into the 1.11's more as the modulation is better. The 3.12's are consistent in feel but I found that they bring me closer to the ABS threshold faster and have less modulation. The 1.11's for me were more confident in that I was able to dig deeper when I wanted to whereas the 3.12' felt like the pedal had less travel. I've been trying to reprogram my brain along the way. I have 1 more set of 3.12's left which I plan on burning through before I make a decision but both pads are good.
Congrats on the little one!!
Tires make a big difference. Jumping from the PS4's up will be a very big upgrade. As you step up in tire the drop from the first couple of heat cycles thereafter will get more pronounced. However this doesn't mean the tires are bad just the way the tires compounds are now a days. My personal preferences are as follows
Another consideration is if you want a tire that can do wet and dry. The Cup 2 will be the best for this. Given the amount of track time you are doing, you should consider having a consumable tracking list which includes tires, brake pads, rotors etc. You track the brands you have purchase, how long they last, cost etc. It will help you in the future not just track budgets but also be smart about upgrades, bulk purchases etc.
Tires make a big difference. Jumping from the PS4's up will be a very big upgrade. As you step up in tire the drop from the first couple of heat cycles thereafter will get more pronounced. However this doesn't mean the tires are bad just the way the tires compounds are now a days. My personal preferences are as follows
- Cup 2's: good tire, very consistent will last you probably 20 - 25 heat cycles. The first three heat cycles will be its fastest and then from from there. Prices are around. Prices ranging in the mid $400's for 19" tire. They run a little narrower to the Pirelli's
- Trofe R: this is my favorite street tire, i personally found it more consistent than the Cup 2's and a little faster. However, they will last 15 to 20 heat cycles Prices ranging in the $500's for the 19" tire
- Cup R: The first two heat cycles is wicket fast then it will drop and be similar to a trofeo. Similarly life span is shorter than the cup 2 and more in line with the trofeo's R in terms of wear. Tires are really expensive though and not offered on our car sizes.
- Hossier: I did not like this tire at all. It came apart within two days. Likes to be run with a lot more tire pressure sue to its soft wall. Very inconsistent.
- Dunlop Sport Maxx Race 2: Probably the most consistent tire of the three above, but sizes won't work with our cars
- Next step is slicks
- Pirelli DH work extremely well. Max heat cycles will be 10 to 15 at most. They do drop quite a bit after the first three heat cycles but they are extremely consistent thereafter. Even after they drop they will run like a brand new R or maybe even a second quicker on a 2 minute lap.
- brand new this tires will average about $650 - $700.
- You can buy scrubs with 5 heat cycles in them for $125. They will last you at least two days depending on your driving style etc.
- Hankook: They are similar to the Hoosiers in speed, but much more consistent like a Pirelli. Also a lot cheaper. Only issue is that you need to run a smaller front tire
- Pirelli DH work extremely well. Max heat cycles will be 10 to 15 at most. They do drop quite a bit after the first three heat cycles but they are extremely consistent thereafter. Even after they drop they will run like a brand new R or maybe even a second quicker on a 2 minute lap.
Another consideration is if you want a tire that can do wet and dry. The Cup 2 will be the best for this. Given the amount of track time you are doing, you should consider having a consumable tracking list which includes tires, brake pads, rotors etc. You track the brands you have purchase, how long they last, cost etc. It will help you in the future not just track budgets but also be smart about upgrades, bulk purchases etc.
I appreciate your thoughts on tires. I'm running another set of the OEM 10 spoke 20" wheels right now but I think in the offseason, moving to a set of 19" rims is the logical step. I drive my car and from the track so I need something that can handle the wet (especially with the crazy Mid-Atlantic weather we get here). I test-fitted a set of OEM 997.1 GT3 RS wheels on the car earlier this week but the rears won't clear so I may look for a nice set of Forgeline's or something I can beat up. Thank you for the knowledge sharing and feedback on tires friend~
11-13-2020, 11:09 AM
#695
Three Wheelin'
Thread Starter
Definitely take a look at AntiGravity batteries, Kong. They are really good, and the auto-restart is critical. (I had to use a pickup strapped to my car and drag it out with the emergency brake engaged once because the battery died and I couldn't get the hood open no matter what I tried. Finally, after dragging it out, and messing up the floor of my trailer...I had to remove a front wheel and locate the emergency release behind the fender liner to get the hood open. I won't use Braille again, just because an accidental discharge from leaving my AIM Solo DL and camera attached can brick the car.) Check out the Antigravity.
The following users liked this post:
KONG991TT (11-14-2020)
11-13-2020, 06:07 PM
#696
Racer
Definitely take a look at AntiGravity batteries, Kong. They are really good, and the auto-restart is critical. (I had to use a pickup strapped to my car and drag it out with the emergency brake engaged once because the battery died and I couldn't get the hood open no matter what I tried. Finally, after dragging it out, and messing up the floor of my trailer...I had to remove a front wheel and locate the emergency release behind the fender liner to get the hood open. I won't use Braille again, just because an accidental discharge from leaving my AIM Solo DL and camera attached can brick the car.) Check out the Antigravity.
11-13-2020, 06:43 PM
#697
Three Wheelin'
Thread Starter
11-13-2020, 06:51 PM
#698
Racer
I've had to jump the car from the fuse box plenty of times, but this particular occasion it did not work. After I got the car pulled out and the hood open and the battery resolved...I discovered that a fuze had blown along the way, which resulted in the fuze box not being able to take a jump start. Yikes!!
11-13-2020, 07:19 PM
#699
11-14-2020, 01:56 AM
#700
11-14-2020, 09:48 AM
#701
11-14-2020, 01:20 PM
#702
Racer
I had a couple of glitches with the antigravity i had. It mainly happened after I had not driven or started the car for a few weeks. Each time the issue happened was that it would start but then it would start acting up. We attributed this to low voltage. The odd thing was after i got the hood opened, the battery showed as it was charged. Went back and he car turned on again.
So when we finished our first build, and we started coding things out, the same issues would happen but this time we would loose all of the work we had done. They work great specially if you drive the car consistently or are able to keep it charged. Since my car spends a lot of time at the shop this wasn't really practice so we decided to take the battery out and use a larger battery. On the new build we are moving the battery to the driver's side foot box similar to a Cup Car.
So when we finished our first build, and we started coding things out, the same issues would happen but this time we would loose all of the work we had done. They work great specially if you drive the car consistently or are able to keep it charged. Since my car spends a lot of time at the shop this wasn't really practice so we decided to take the battery out and use a larger battery. On the new build we are moving the battery to the driver's side foot box similar to a Cup Car.
11-14-2020, 01:41 PM
#703
I had a couple of glitches with the antigravity i had. It mainly happened after I had not driven or started the car for a few weeks. Each time the issue happened was that it would start but then it would start acting up. We attributed this to low voltage. The odd thing was after i got the hood opened, the battery showed as it was charged. Went back and he car turned on again.
So when we finished our first build, and we started coding things out, the same issues would happen but this time we would loose all of the work we had done. They work great specially if you drive the car consistently or are able to keep it charged. Since my car spends a lot of time at the shop this wasn't really practice so we decided to take the battery out and use a larger battery. On the new build we are moving the battery to the driver's side foot box similar to a Cup Car.
So when we finished our first build, and we started coding things out, the same issues would happen but this time we would loose all of the work we had done. They work great specially if you drive the car consistently or are able to keep it charged. Since my car spends a lot of time at the shop this wasn't really practice so we decided to take the battery out and use a larger battery. On the new build we are moving the battery to the driver's side foot box similar to a Cup Car.
11-15-2020, 02:38 AM
#704
was at the shop getting my K40 installed and they had everything turned on for a long time without starting the car.
I have the very lightest version...9.8 pounds so it’s good for about 30 minutes with the air and lights and radio on etc...twice they ran it down.
the fob was useful because I didn’t want them jumping a Lithium battery with their shop charger
I have the very lightest version...9.8 pounds so it’s good for about 30 minutes with the air and lights and radio on etc...twice they ran it down.
the fob was useful because I didn’t want them jumping a Lithium battery with their shop charger
11-15-2020, 02:43 AM
#705
I had a couple of glitches with the antigravity i had. It mainly happened after I had not driven or started the car for a few weeks. Each time the issue happened was that it would start but then it would start acting up. We attributed this to low voltage. The odd thing was after i got the hood opened, the battery showed as it was charged. Went back and he car turned on again.
So when we finished our first build, and we started coding things out, the same issues would happen but this time we would loose all of the work we had done. They work great specially if you drive the car consistently or are able to keep it charged. Since my car spends a lot of time at the shop this wasn't really practice so we decided to take the battery out and use a larger battery. On the new build we are moving the battery to the driver's side foot box similar to a Cup Car.
So when we finished our first build, and we started coding things out, the same issues would happen but this time we would loose all of the work we had done. They work great specially if you drive the car consistently or are able to keep it charged. Since my car spends a lot of time at the shop this wasn't really practice so we decided to take the battery out and use a larger battery. On the new build we are moving the battery to the driver's side foot box similar to a Cup Car.
the lithium is great for driving and I never had an issue even leaving it for 3 weeks without starting and it started right up...but if I’m going to be using the power without starting the car for 20 or 30 minutes of tuning etc I use the stock bigger battery precisely because once I had the Lithium one get too low and it interrupted my Cobb retune while uploading, had to do recovery mode