Leigh2

The difference between the 6GT3 and 7GT3 motors seems to be a larger throttle body and different exhaust. Has anyone put the (415mm???) 7GT3 throttle body on a 6GT3? If so what's required??

Also what would be the recommended exhaust for street/track? Cats are optional, not checked where we are but CEL's are a pain...

4porsh

Do not know the answer to your first question. I am however trying to get a few more 996 GT3 guys on board for a group buy on full custom made exhaust with no CELs, no loss of power/with gains, and takes 60-70 pounds off the rear.
Check your PM.

Joe

911SLOW

Many more differences..
Compression, rev limiter, intake,heads, crankcase breather, dme, exhaust, 82TB etc etc.
With that being said the easiest way to gain 10-20 hp is the exhaust.
The oem piping's diameter , cats and configuration were an issue. The headers though are good.
Use 63mm to 76mm piping and 100-200 cell cats or nothing.
An ecu upgrade would also help dealing with check engine lights and to free another few horses.

The 7series throttle body can be installed in the oem plenum if you do some work on it to enlarge it to 79-80mm.(the max it can go)
The other way is to use the IPD plenum.
Unfortunately it doesn't work, at least in an already sorted out 6.




Btw most RoW 6gt3 dynoed at 390hp.

mooty

just keep it stock, it's your street car. stop messing around peter.

Number54

In the Total 911 issue with the Sharkwerks 3.9L 996 GT3, it was mentioned that the 997 throttle body + IPD plenum is a worthwhile upgrade. What's that all about? I presume you need exhaust + tune for that too but it wasn't mentioned.

This seems like the worst platform to try to increase power, 30K for 100HP. Turbo lovers will laugh at this.

ukrbmw

Yep, I've read all the stuff on this board about power. Pretty much the best you can hope for with larger TB, IPD plenum, exhaust, good tune 380ish. Considering they are doing 355ish stock seems like a lot of effort for 25 or so horsepower.

911SLOW

It's tough to improve any N/A motor that makes this kind of power per/l..
Besides this car needs weight off , power is fine.
Playing with the exhaust, especially when you don't have to comply with sound limits, allows you to do a little bit of both.

For the IPD plenum, here are my dyno results:

https://rennlist.com/forums/8062445-post104.html

FFaust

I don't know but, the 997 is said to have 415 v. the 996's 380 (all on paper of course), but when on the track side by side, it sure looks like more than a 35hp delta?

Mr Michael B

That a-boy Slow. I luv that. "Here look for yourself" Amen.

Leigh2

John! It's the usual cycle; buy the car, spend a bundle and when there's nothing left to change sell it and start over again. I'm explaining this to you? You're inflicted worse than me

So it looks like exhaust and some software and that's that. One thing I do want is an exhaust that's easily changed for sound restricted venues like Laguna. So best to have one that I can still bolt the stock mufflers or cats back onto if it doesn't meet sound.

Leigh2

When I bought my 7GT3 race car I got a dyno sheet showing 395 RWHP. It has now had some exhaust and other changes and is back on the dyno shortly so we'll see if that's improved at all. If I can get 380ish out of the 6 that would be perfect....

AudiOn19s

RS rear air scoop?
RS pulley?

everything else has been covered.

Leigh2

Car has the single mass flywheel and appropriate pulley already plus I'll do the 3, 4, 5 gear change...I'll check out the RS air scoops though. This is such a disease...

jrgordonsenior

We compared OEM throttle body & plenum to the larger 82mm TB & honed out w/OEM plenum. We also switched ECU's from OEM to one with GIAC's 6-GT3 flash. We got 23(IIRC) rwhp back to back, 30 minutes apart never leaving the dyno. Exhaust for both tests was OEM headers to straight pipes....

Leigh2

Thanks John, great data...
Do you think there are any advantages to the honed out OEM plenum over the IPD???