88 Carrera 3.2 Performance Questions

[motiv8ed]

I'm a long time owner of a 78 SC with M21/964 Cams, SSI's and Dansk Sport muffler. I've also lightened it with glass front and rear bumpers. Its a very light car anyway with no factory a/c or power anything, etc. Factory sport seats and limited slip really round out the raw sportscar feel. I love the performance of this car and would love to replicate it in the 88 Carrera I've just purchased. I've a few questions:

Do SSI's and a dual inlet single outlet sport muffler have the same profound effect on the 3.2 with its stock FI as they do on the 3.0 with CSI? If not, is there a way to gain substantial performance via retainment of the majority of the stock exhaust system?

I've read 850K threads on chips....whats the real deal?

Thanks

[911st]

Go to 911Chips.com and look at the dyno section.

My conclusion is that with a low overlap cam like on the Carrrea back pressure is the main issue and you do not get the same kick long tube equal length tubes give you like on an early pre smog or race cam.

If you take the cat off and put a sport muffler on (or just add a second tail pipe to the right side) you will equal a SSI/sport muffler in peak HP.

There is an extra blip in HP around 3k for the SSI. Note that the factory HE primary tubes are larger than the SSI's 1.5".

After a good tune w fresh air cleaner element, cat bypass, sport muff and SW chip, HP is expensive to come by. Based on my car and one other with similar mods on the same dyno here we get 215-220 rwhp or about 250fwhp with this combo.

I do not think cams are worth the effort on a stock 3.2. A 3.4 is different.

Best exhaust seems to be a 1 5/8 with a race muffler for another 10hp, race fuel only chip only can add yet another 10hp.

Still, the SSI is an elegant addition with great sounds. For me, not worth the money yet.

[vanwyk4257]

Good advice from 911st. I have a cat bypass, custom sport muffler and a Steve Wong chip in my '87 and it completely transformed the power versus the stock setup. The SSI's do sound a bit nicer, but I wouldn't really bother with them. If you can live without heat just run headers.

[WIL84911]

just got on SSI's w/ 2/1 M&K's + SW chip. world of difference for me. love the sound and the noticeable improvement on all ranges specially low rpm's. would do it again on my next 3.2.

[spence88mph]

People rave about 993 HEs and a dual in muffler. I would do that if I had my NA time again.

I did chip, fabspeed cat bypass and monty muffler, sounded a lot better but the performance was barely noticeable maybe a little bit... I always had in the back of my mind that the engine is pretty low compression and it would never be a barn storm unless that changed.

[911st]

993 HE's are the best of the bunch except for the pre 74's.

They are still a short tube, unequal length header and as such should still be leaving some opportunity on the table.

What they do is eliminate the funky cross over of a 3.2 or C2 system.

They have proven to be a good base for a Turbo exhaust and make some improvements on the C2 where a header system with heat is expensive and there may not be many good choices.

I suspect on a 3.2 car the SSI will be an advantage for a driver. The 993's might help at 6k rpm plus.

Just my two cents worth.

[911-32]

Originally Posted by 911st

993 HE's are the best of the bunch except for the pre 74's.

They are still a short tube, unequal length header and as such should still be leaving some opportunity on the table.

What they do is eliminate the funky cross over of a 3.2 or C2 system.

They have proven to be a good base for a Turbo exhaust and make some improvements on the C2 where a header system with heat is expensive and there may not be many good choices.

I suspect on a 3.2 car the SSI will be an advantage for a driver. The 993's might help at 6k rpm plus.

Just my two cents worth.

I have done most of this stuff on my 3.2 so here is my $0.02.

Currently I have a euro 3.2 with 993HEs, M&K rallye style 2-out, 993 Supercup cams and light port polished heads with 911Chips custom chip tuning. Don't know what hp it makes right now but the same engine with SSIs and M&K 2-out previously made 260fwhp. I have seen plenty of chipped euro 3.2s making 250-255fwhp. The cams are not worthless IMHO, as they let you hold the tq a good 4-500rpm higher which translates to hp. If I had to guess, I would say the engine feels stronger with the 993HEs but the dyno test (on a different dyno) was inconclusive.

In theory 993HEs are spot on for size and the lack of equal length is neither here nor there given the limited lift and overlap cams you can run with the std pistons and the flapper AFM. However, most of the euro 3.2s I have seen making 250-255fwhp are doing so on std x-over exhausts with perhaps a new x-over pipe and pre-muffler, so not that much wrong with the std exhaust IMHO.

I am next going to try the engine with a late 964 plastic intake which IMHO will get it pretty close to ideal for an engine still using std Ps&Cs without spending silly money. I am optimistic that I can see close to 270fwhp but lets wait and see.

If the early character is what the OP is after, then cams are a help and I would also recommend an aluminium pressure plate and light spring centred clutch - which my car also runs. Together you get more zing round the second half of the rev counter and it doesn't run out of puff at 6200rpm like a std 3.2. I may not have spectacular hp but my engine is a real peach with just the character I was hoping for. Everyone who drives it is impressed with the way it feels.

RB

[scarceller]

I have a 3.2L with SSIs and 2in2out M&K pipe and love the setup but I think the SSIs are to small and you give up some HP in the 5-6K RPM range. I think the SSIs work well in the 3.0 but are under-sized for the 3.2, just a educated guess.

[ISpeed2day]

make your car weigh less... That is what we used to do in the old days...

[motiv8ed]

Thanks everyone for some great feedback. Here's the deal: I've got a "like new" set of HE's that came off of my low mileage 71T. I also have a set of SSI's on my 78 SC but I assume theres no advantage to them over the stock HE's other than the SS so I'll likely just keep them on the SC. I probably contact M&K for a muffler selection.

Is the installation of the early HE's a pretty straightforward deal? Are there any heat ducting issues or O2 sensors or anything else I need to be aware of?

Thanks

[scarceller]

If you get a M&K pipe get the 2in2out pipe and then get the optional cap to cap one of the outputs. This will give you the ability to turn the 2in2out into a 2in1out, I do this all the time. The family likes the 1 out sound + nice for long drives.

Ask M&K about this.

[RideShoot&Drink]

I had SSI's, SW chip and Monty muffler on my ex 85 Carrera, and didn't feel much of a difference. If I were to do it again, I'd do cat bypass, sport muffler and chip, JMHO.