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I have the fabspeed xpipe w/200 cell cats and fister stage 2 and to my ears it’s absolutely perfect. However exhaust is subjective, I can tell you it originally had maxflo mufflers and was silent so you can easily tune the sound with mufflers of choice but I highly recommend the xpipe at a minimum
Ive been researching gears as well and seems like the common observation is the price/performance ratio of fixing the 1-2 drop issue as all 96+ cars have 1-2 gears fixed to the mainshaft and cannot be replaced individually, a new mainshaft cost apparently is not for the faint of heart but you did a full 3.8 rebuild so it’s probably all relative. Seems the common knowledge is you use 2-5 mostly so why bother, though I agree the 1-2 shift is really weak on these cars
If your use case is tight winding roads, you probably won’t be shifting much and would either be in 2 or 3rd gear at all times, I would think the extra torque you just gained in gear with the 3.8L upgrade would negate the necessity for new gears? I’d like to hear an expert weigh I on this
Obviously if $$ is no object at all sure go for it, but if one were to think about $/performance wouldnt the equation be 3.8L OR re-gear? Seems like each accomplish the same thing in their own
anyway here is a handy graph I found here on useful gear ratios, please let us know what you decide as I’m researchig similar options. Thanks!
I have saneproduction's old C4 3.8 w/the regear as outlined in the chart and the ratios he selected were spot on for in town and highway cruising. Changing out 2nd required another $2k for the mainshaft and gears, but worth the $$$ as now the 1-2 shift feels normal vs too wide as it was in my stock 96. In town, I can leave it in 3rd most of the time. I actually use 6th now on the freeway where on my 96, I rarely got out of 5th unless out in the flat open road which was rare in the Pacific NW. As part of the 3.8 build, Mike put in 100cell cats w/Fister stage 1's. Again, another great combo, it has presence in town, but its reasonable on the highway where I can listen to the radio and have a conversation in the car.
Thanks for sharing, those ratios look about perfect and what I’m leaning towards. Are you saying you used to keep your car in 5th on the freeway? I see a lot of people take the old .0921 5th and move it to 6th to avoid buying another gear, but wondering if that’s too aggressive cruising at 75-85 (I guess I can go try it myself). Seems like your 6th gear selection is about perfect. Also cool that they are all factory Porsche gears vs. aftermarket, wonder what the cost difference is going that route
I have saneproduction's old C4 3.8 w/the regear as outlined in the chart and the ratios he selected were spot on for in town and highway cruising. Changing out 2nd required another $2k for the mainshaft and gears, but worth the $$$ as now the 1-2 shift feels normal vs too wide as it was in my stock 96. In town, I can leave it in 3rd most of the time. I actually use 6th now on the freeway where on my 96, I rarely got out of 5th unless out in the flat open road which was rare in the Pacific NW. As part of the 3.8 build, Mike put in 100cell cats w/Fister stage 1's. Again, another great combo, it has presence in town, but its reasonable on the highway where I can listen to the radio and have a conversation in the car.
Thank you, this sounds fantastic. This was basically what I was looking at doing without 2nd, but you may have just convinced me to change out 2nd and the mainshaft as well. All factory gears which is perfect. The 100 cell / Fister I exhaust setup seems very popular.
Now I am on the fence about RS flywheel. Some say it is noisy, to quote @Martin S. in this helpful thread from 2016 “At idle, in neutral with the clutch out, it sounds like a collection of bolts and nuts rattling around in an old fashioned metal coffee can. Push the clutch in...the noise goes away.” I do have RS motor mounts but a stock transmission mount. Car also has FD Goldenrod and AWD SSK. What is the 4.0 disc they refer to later in the thread? I assume they are talking about the 997 GT3 RS 4.0 clutch disc? RL’er @OverBoosted28 said with this, he has no rattling sounds.
Thanks for sharing, those ratios look about perfect and what I’m leaning towards. Are you saying you used to keep your car in 5th on the freeway? I see a lot of people take the old .0921 5th and move it to 6th to avoid buying another gear, but wondering if that’s too aggressive cruising at 75-85 (I guess I can go try it myself). Seems like your 6th gear selection is about perfect. Also cool that they are all factory Porsche gears vs. aftermarket, wonder what the cost difference is going that route
cool car! Sounds perfectly set up
In my stock 96, I would only use 6th when just cruising on the open road over 75mph which was impossible around my area until now w/the stay at home orders. I think using the stock 5th as the new 6th might be a little too aggressive if you ever plan to use the car for road trips. But for the track or just spirited driving or even in town/suburban setting, that would work, especially if you want to save some $.
I did a quick video of getting on the highway today so you can hear the exhaust from the inside with the windows closed.
BTW, with the 996 GT3 6th, the engine is approx at 2600 rpm at 70mph and around 2900rpm at 80mph.
Nice vids. Don't have a vid of my exhaust, but it's 100 cell cats with stock mufflers. Much different sound, both the tone and volume. Quieter for sure and less rumbly.
@L39E - I had the LWFW and clutch in my last car, its definitely noisier at idle as mentioned and up to about 3500 rpm. It depends on what you're going for, for some the mechanical sounds add to the experience, to others it sounds like something is broken in your transmission. I also noticed a big trade off of the friendliness of the LWFW and clutch around town, it seemed more difficult and annoying to use at start/stops and slow speeds. Much more of an on/off switch type feel to it, but who knows maybe my clutch was overly worn or something. As far as responsiveness in acceleration, I dont know - yes it was a bit more responsive feeling but cant say dramatic compared to the stock clutch when in gear and accelerating, for sure yes to blip in heel-toe if you're doing that often. The big thing is weight savings as you can carve out 18 lbs by using it. SO my feedback would be if you're building a backroad monster with focus on removing all possible weight than yes, do LWFW. If you're building more of a GT experience I dont think the positives of 18 lbs of savings would be noticed vs. the tradeoffs of NVH and use-ability of the stock set up. Just my $.02 based on my personal experiences
3.8L (adds 25hp from stock?) results a car equaling power to a V6 Camry sold today. Outside of this, losing weight and introducing forced induction is probably the easiest way to feel and find additional power. High altitude performance robbing is an issue in all cars due to thinner air. If you are going to ship your car between FL and CO, then finding a way to adjust boost level is recommended.
My favorite exhaust is 100cell and Fister I combo but opinions vary
My car is set up this way: gearing, RS clutch/flywheel, lightweight wheels. The effect is that the car revs very freely through the gears and it's very noticeable vs stock.
If your still working on gearing, I would suggest you don't leave 2nd alone. The biggest frustration with the gearing in a US 993 is the shift from first to second. The gap is too big and RPMs drop too much. I would absolutely close that gap if I was going to touch the gearing.
I have the RS flywheel and it clatters around a little in neutral. It's not noisy at all when driving - can't even tell the difference. The flywheel is a very natural complement to gearing. Do it. Less mass in the drivetrain will make the car feel like it has more power -- particularly when you have shorter gearing (get some lightweight wheels too).
Biggest negative from me with the RS flywheel/clutch is starting from a stop on a very steep hill which isn't an issue in Florida but might be at elevation. It's not unmanageable but it definitely adds a little to the fun.
My polar silver '96 C4S has recently completed a 3.8 conversion. The engine was built by Gulf Performance with bore-in Mahle 3.8 RSR pistons and cylinders, Pauter rods, custom Elgin cams and some other trick extras. The car already has a very good suspension setup, with PSS10, RS tie rods/wheel carriers, front and rear RS adjustable swaybars, RS motor mounts, Elephant bushings, etc.
Sadly, the shop owner and mastermind of my build Vinnie Colosino passed away in the fall after a courageous battle with cancer. Vinnie was a great friend of mine and a huge asset to our community. His shop has been continuing business to honor his legacy, which is truly wonderful. However without Vinnie's great trove of knowledge, I am turning to the RL community for some help to get this project across the finish line. The engine is complete - I just need some advice on gearing, exhaust and ECU.
Gearing
While the car is currently in Florida, I will almost certainly ship it to Park City, Utah when the project is complete. Our home in Utah is at 7,000ft altitude and most of the driving I do is canyon carving at 5,000-9,000+ ft above sea level. As such, I want to regear the car to take advantage of the increased power band in the 3.8 motor - at altitude. One suggestion, which came by way of Gbox transmission in Colorado was to leave 1st, 2nd, and 6th alone and change 3rd, 4th and 5th to factory gears from a 997 (turbo?) GT3 RS with a 1.55:1 3rd, 1.38:1 4th and 1.1:1 5th. These are factory gears and they come with steel synchros. I have read many, many regear threads in this forum and one hesitation I have to the Gbox approach is the RPM drop from 1st to 2nd. If anyone has done a 3.8 conversion WITHOUT a re-gear, I would appreciate your feedback on the 1-2 drop with the beefier motor. I could go with a full set of gears with custom ratios as well. I do like the idea of the factory Porsche gears, and am wary of adding aftermarket gears, which would be more noisy. If anyone has suggestions for my situation (3.8, high altitude canyon carver, AWD) it would be very welcome.
Exhaust
I am also contemplating whether it would make sense to change the exhaust to let the motor breathe better given all the other improvements. Right now, the car has the stock motor sound airbox and a Fister III exhaust that I bought several years ago. I kept the stock mufflers, so I have those as well. For all with a 3.8, is there an exhaust system that would be more appropriate for the higher HP motor, without sounding completely ridiculous? I know exhaust sound is subjective. I do like the sound clips I have heard with the Fister II and Fabspeed Sport Cats. I also like my wide oval exhaust tips, and don't want to change them. Should I leave this alone with Fister III, perhaps add the sport cats or is there a better option?
ECU
As my car is an early '96, I have read that it is difficult/ to flash the ECU. This is somewhat confusing. I am not sure if I could/should send out my ECU to be reprogrammed, or if I should try to source a '97 ECU to use for this project. Is there any definitive answer as to what is possible with my '96 ECU?EDIT: I bought Kika’s ’97 ECU and will have it flashed, most likely by Steve W.
I appreciate any and all input from the experts. Here are a couple photos of the car for good measure. Thank you and stay safe everyone.
Beautiful and very juicy mods for a very desirable 993, it would be nice to know something g more regarding the engine performance.
In regards to the exhaust, on my silver 993 I installed this beautiful, effective, and handcraft Italian made exhaust (primaries, x-pipe with high flow cat, and stock mufflers).
My car isnt 3,8 and doesn't have bigger outer exhaust ports (the primaries if I remember well are 42mm diameter, a bit larger for the 3,6 ports), but apart the beautiful sound, racing style sound stamp, it isn't high or disturbing while running not under heavy throttle load, I find it is very nice, and while pushing in the green hills or in the circuit, wow, you damn recognise it...and it doesn't sound like an electric 992, definitely it doesn't.
A friend of mine had same car as me, he installed the kit sound sport sound genuine from porsche mufflers, and I think it was ridiculous the way the system worked, because he had a much bossier sound at low revs & and low load, not a very natural sound stamp, and from mid range to redline same sound as with normal mufflers.
I was thinking: whaaaat? Not for me, thanks but no thanks.
My exhaust system maintain always the same sound stamp, it just is louder or smoother accordingly to throttle load and revving.
So it is up to me, i.e. my right foot, whether to be quiet and very well educated while driving in the city or not.
it is also very nice the weight savings: right now I am looking for a dB killer to erase the mufflers or titanium handmade RS design mufflers, to move it all on another car.
My car is set up this way: gearing, RS clutch/flywheel, lightweight wheels. The effect is that the car revs very freely through the gears and it's very noticeable vs stock.
If your still working on gearing, I would suggest you don't leave 2nd alone. The biggest frustration with the gearing in a US 993 is the shift from first to second. The gap is too big and RPMs drop too much. I would absolutely close that gap if I was going to touch the gearing.
I have the RS flywheel and it clatters around a little in neutral. It's not noisy at all when driving - can't even tell the difference. The flywheel is a very natural complement to gearing. Do it. Less mass in the drivetrain will make the car feel like it has more power -- particularly when you have shorter gearing (get some lightweight wheels too).
Biggest negative from me with the RS flywheel/clutch is starting from a stop on a very steep hill which isn't an issue in Florida but might be at elevation. It's not unmanageable but it definitely adds a little to the fun.
Good luck with your project.
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Thank you for the input. I did end up ordering the gears and bit the bullet to do 2nd with all factory Porsche gears. 1st through 5th will use 997 GT3 gears and 6th from a 996 GT3. The ratios will be:
04-28-2020, 02:42 AM
