calrcm

I have an early 86 928 and would like to do some minor mods for more power. I'm installing the Autothority Stage 1 chips now and would like to install a "true" cat back dual exahust. Anyone out there know of one besides that offered by 928 Motorsports? I think that one looks great but the cost is prohibitive. Any thoughts on the Xpipe /w cats run through the OEM cat back system?

Thanks

Mike Frye

I am running the Motorsports crossovers with the high flow cats, with the rest of the exhaust system stock. I like it alot! More power (dyno proven) but still not too loud. I think Roger (928sRUs.com) also sells them. I'm also using the Autothority chips.

I'm saving up for the 'true dual exhaust' from 928 Motorsports, it's a bit pricey, but I'm thinking it's worth it. I don't think there's another system out there for our cars, so you'd have to get into some custom work and even more $$$. I'd go with Carl.

So tell us about your car. What color? Got pics?

Imo000

If cost is the issue (and it is with most of us) you can try to find someone that bought an X-pipe and is selling their old H-pipe. I‘m not talking about the factory H with the cats but the ones that were sold before the X hit the market. They are a great improvement over stock. Might not have the same performance gains as a Y but it’s about 80% as efficient and they are usually around $75.

ROG100

I have SS and Aluminized steel X pipes and cats in stock.
Roger@928sRus.com

F451

I've heard, but cannot say from experience, that the '85 - '86's get a significant performance gain from an X-pipe & chip upgrade. For under a grand, you get a serious hp jump is my understanding.

PorKen

X'n'chips + RMB, and stock 86.5 big resonators, routinely makes for 288/287 rear wheel HP/TQ.

Factory states 288/302 crank HP/TQ.

Imo000

Yup they are stronger than most people think! From ¼ mile, weight and time calculations were all in the 288RWHP range and this was with only chips and nothing else. Full weight too.

BIMMERMIKE

Chips sitting on my desk, well packaged, now I need an x pipe.

Mike Frye

calrcm

My car is an early 86 5 speed I picked up cheap from a guy who found out the hard way what it costs to maintian a 928! I'm just about finished going through it. Its got a new engine and paint job & 17"cup wheels. 90% of the systems are operational (need to get a new CD / radio for it, still messing with the cruise control.) but the rest is solid. The car is fantastic but I am lookin to get more power without supercharging it (I had a supercharged M-3 a few years back and that did not turn out well) Attached is a pic of my baby!

Mike Frye

Cal,

Welcome to the group! You should start a 'Here I am' thread and introduce yourself. It's a beautiful car.

We're having a GTG (get together) on the 15th of September, you should come down. Watch for a thread called 'Sharks at the Beach'.

Chips and crossovers are a great start!

James-man

86.5 with chips, X-over pipe, stock resonators/mufflers and a Rear Muffler Bypass, seems to be well proven route.

Question may be: how easy would it be to set this up on an 85 or early 86?

(I already have these things on my 86.5, just trying to help those without the 1/2)

RDS928S

Early 86 recipe for mo' power is:

Autothority software.
Electric fans from Motorsports. Call D. Lomas.
X-pipe & 100 cell cats from Motorsports. Call D.Lomas.
Air air pump delete.
Adjustable fuel pressure regulator. Call 928 Specialist.
2.5 inch true dual exhaust from www.mufflex-performance.com in Trenton NJ.
https://rennlist.com/forums/showthre...m+dual+exhaust

Good Luck
Rich

Mike Frye

Rich,

What do you gain from the adjustable FPR? I thought the fuel was metered by the injectors and the stock fuel pump. I always thought the adjustable FPR was for boosted cars that have lots more variables to deal with.

RDS928S

Mike,

AFPR is reccomended for motors that are modified especially with larger diameter exhaust.
D.Lomas noted the 32 valve motor leaned out with 2.5 inch diameter pipes all the way back.
Fuel tunning on a dyno is really needed for optimum gains.

Rich