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I know a lot of folks here have done just R&P. I think @HarmonyJim and maybe @christallon have both done this on their Pumpkins.
I have the 4.0 R&P with factory gears in my 997.1, top speed is around 175 mp/h with factory tire diameter. I've never actually got up there, so the lower top speed doesn't bother me, and the gearing is so much better than stock. However at 75 mph, 6th gear is like 3600ish rpm so that's a bit annoying on long highway drives.
I have the 7.2GT3 with the RS drivetrain which includes the shorter RS gearing with the 3.89R/P, taller 6th, and the RS 4.0LWFW clutch set up. This is the way these cars should have come from the factory. Prior to the RS drivetrain conversion, I found the car utterly boring and rarely drove it. Now I absolutely love it. With the side muffler delete, lightweight bucket seats and a lightweight LiOn battery it's just about the perfect light and nimble street / track car. The non RS 7.2 body without the large RS rear wing and overt stickers is a more understated, some would say, prettier sleeker body. I really love this car as a fun weekend car. I doubt I'll ever sell this one. For track and racing I have a much faster dedicated 996.
Agreed! Shorter r&p is a dramatic difference. if you guys could get over the (admitted) aesthetic disadvantages, you would love my 996 with the rs 3.89 r&p, lwfw set up, 3.9l engine and sub 3,000 pound package!
If I am not mistaken, gear ratios are the same between the 3.8 and the 3.8 RS. Back in the DE days, the proper way to maximize gearing was to move 5th gear to 6th, and replace 3-5. But imo that's overkill. Only the RP is different. RS is 3.89. If you are planning on doing the RS ring and pinion, I would suggest upgrading the rear diff. I had a cup car diff and was quite happy with it. No more tail wiggle under braking. Or do Guards
And not to complicate it even more, but if you have the 4.0 clutch/lwfw, maybe plan on a dampener to avoid the loosening of cam sprockets. Or just yours and retighten. There is an harmonic issue when you go with the clutch flywheel package. I was skeptical in the beginning but have heard more than enough stories of loose cam bolts than I would get the dampener just in case. Or lock tight the **** out of the existing ones
Luckily, I bought a great car which had the cam bolts addressed. I couldn't buy it fast enough once i had the full service records. RS 4.0 Steer wheel, LWFW and clutch, coolant lines pinned, cam bolts repair done, 5 lug conversion.
With the shorter r&p, usually recommended to swap sixth gear to at least the RS gear ratio so you aren't running at 3500 rpm on the highway. There's been some talk of even swapping to the sixth gear from the 997 Turbo, which should drop the freeway rpm even more. These cars already sit fairly high on the tach at 75+ mph so it may be beneficial for cruising.
If you're already going through the effort to pull the trans you might as well tackle the sixth gear at the same time given the relatively low increased cost from the r&p swap alone. Beats not doing it and then having to pull the trans again if it ends up bugging you.
whats the cost of the RS gearing and 3.89 R/P? I already have the 4.0 clutch and LWFW.
Your set up sounds like exactly what my car is missing.
Current pricing on the 3.89 R/P is about $4200 and the RS 6th is about $1500. The parts have gone up significantly. 2 years ago I paid $4K shipped for both the 3.89 and 6th.
Labor on top of that obviously. I did the Guard LSD clutches while it was all apart. The clutches are about $1200 if I recall.
Last edited by powdrhound; 01-17-2024 at 07:10 PM.
I'm not sure it's accurate that 7.2 and 7.2RS are the same.
I think 997.1 GT3, GT3 RS and 997.2 GT3 have all the same gear ratios and the long 3.44:1 R&P gear.
3.8RS and 4.0RS got the 3.88:1 shorter R&P (8:31), and a longer 6th gear.
Double check that info tho.
7.2 and 7.2RS 1-5 gears are the same. 7.2RS gets the taller 6th and the 3.89RP in place of the 3.44RP on the 7.2. 7.2RS get the LWFW clutch while the 7.2 gets a DMFW. Both the 7.2 and 7.2RS already have the same lightweight crankshaft pulley.
In summary, to get the RS drivetrain in the non RS car, install the 3.89RP, taller 6th, and the LWFW clutch package. Done.
Last edited by powdrhound; 01-17-2024 at 07:16 PM.
Has anyone modified 2nd and 3rd gear as well? The stock drop between 1st and 2nd isn't great on the street or auto-x. I saw Albins has some other ratios available.
This chart below is with a modified 2nd,3rd, and GT2 6th w/ the RS R/P.
Agreed! Shorter r&p is a dramatic difference. if you guys could get over the (admitted) aesthetic disadvantages, you would love my 996 with the rs 3.89 r&p, lwfw set up, 3.9l engine and sub 3,000 pound package!
can't even imagine how that thing drives. I drove a stock 996 gt3 recently and was blown away with how awesome it was. In some ways, i like it better than my 997.2 GT3. The only downside for me is the looks but outside of that it's an amazing car and probably a much better value than a 997 GT3. had i driven one sooner, I would've likely bought one instead of mine.
I heard adding a LWFW to a GT3 can damage the engine. Believe they stated it in the manual and voided the warranty if one was installed.
Sounds like scare tactics. I mean the RS has a lwfw. But the dealers deny the cam bolts issue, so you’re effed either way. Same situation with coolant pipes. Porsche will never accept that issue.
If you do lwfw, just have to be smart and do preventative maintenance.
Agreed! Shorter r&p is a dramatic difference. if you guys could get over the (admitted) aesthetic disadvantages, you would love my 996 with the rs 3.89 r&p, lwfw set up, 3.9l engine and sub 3,000 pound package!
Scott, you may have covered this back when you did it but do you mind reminding us what it cost to get your engine turned into a 3.9L?
Since we've completely hijacked the poor OP's original thread for re-gearing talk, I'll keep it going . . .
Seems like folks are primarily only doing 6th and 3.8/4/0 R+P. No shorter 2-5? Why or why not ? Certainly in favor of the cheaper solution if that's all we need to convert 7.1, non-RS 7.2 to the way it "should be."