BlackOp

I recently bought a 951...the PO put something on this that is not factory and definitely not 3". My guess is he took off the upgraded system to curb his losses...the rest of the car is sorted.

So...I'm on a fence about which direction to move. I can replace this with a used factory cat-back for around $150-200 or spend around $700 on a 3". The car has a Tial waste-gate and I plan on chipping it.

Thoughts?

V2Rocket

3"...opening up the exhaust will make all your future mods work that little bit more...plus it's new and shiny

BlackOp

Well...right now it's essentially stock and I'm pretty happy with it. I just want to confirm this $700 investment makes a difference worth the cost.

86 951 Driver

you might be able to get a custom exhaust made cheaper. A test pipe and a 2.5" exhaust will suffice til at least 300 WHP. Once you get past that 3" exhaust shows a huge advantage especially when you use a bigger downpipe.

BlackOp

So..I was under the impression that you needed a 3" first or chipping it was a waste. Essentially my thinking was...waste-gate, 3" and a chip. I want a faster spool but also a reliable car....around 275HP. Will these three mods get me close?

xsboost90

my car had a lindsey racing 3" exhaust, no cat and 3" magnaflow muffler- 359rwhp at 21psi.
sam's car with almost all the same mods, similar turbo and 2.5" exhaust w/ cat delete- 358rwhp at 21psi

BlackOp

Hmmm. ...now I'm confused. So if I just chip my car with a Lindsey kit and replace my cat-back with a factory unit (used)...I will see improvement? Also...with a stock cat-back, I can go with a MBC and 3.0 FPR?

Darwantae951

Are we talking just the cat-back here? Or test pipe?

onspeed

Wouldn't bother with a pricy 3'' system, unless you plan to go over ~350rwhp.

2.5'' test pipe should suffice. It's mandrel bent, and not double walled like the stock 2.5'' cat pipe. Stock catback. I actually have a test pipe for sale.

Also wouldn't bother with the LR chip set. Do it once, do right - go with a MAF kit. Had an M-Tune from Rogue and it was fantastic. With the test pipe, MAF kit, and a new wastegate + MBC, you'll find out that the turbo is the limiting factor. The k26/6 on the 86-88non-S, generally peaks at 260-270rwhp.

Just my .02$

advrider1967

1986 951, 92k miles, stock turbo, CAT delete (Ansa), Borla CAT back in 2.5" with vintage Waltmeister chip set, shimmed WG. A MAF kit will improve the throttle response as well as remove enough pumping restriction to net ~2 psi increase in boost. The turbo is the limiting factor now:

BlackOp

Wow...almost a 75hp improvement @ 4000. That's pretty much what I'd like. Is that dyno with the MAF installed?

FRporscheman

How about this?
https://rennlist.com/forums/944-turb...tures-now.html

Even if you can't weld, a muffler shop can do it for you for very cheap. Or you could have the muffler shop make you the whole system for probably around the same cost or less (but how nicely it's bent or how well it fits might be a crapshoot).

Stephencs601

Plain and simple, do the most you can when you can. It will all come together in the future. The larger the exhaust, the better for future mods. My car has a4" exhaust and other mods. Look at the Mtune at Roguetuning.com It all comes down to what you want and how much you can invest. My last thing is more suspenson work and then thats it for a while. Car is in for paint now.