danglerb

Y pipe and cat back exhaust.

Higher stall converter.

OSP

Yes, exactly! with headers.... Now the only issue is finding a shop that can do the work in western new york or erie pa...

Landseer

Headers could be 85 or 86 SS units, stock.
Would need a short adapter piece on one side to match header to Y.

928SS

I had msds headers on my 85 w/a custom free flow system. didn't do much over 9rwhp. did give me a headache cause it was so loud w/the monster single exhaust though. couldn't tell the diff in power either. maybe a tad more throttle response, but w/all the racket, who knows.

then I did the chips. hardly a change at all. the 85 had very aggressive cams and timing already. but it had smaller valves than the GT heads, and no flappy thingy, which is why the GT has a few more chp.

then I tried some devek L2 headers w/xpipe. that got it about 14rwhp.

then I did a stroker w/a bunch of mods/ported gt heads/cams/6.5L, etc. that got it 360rwhp and 440ft lbs at the rear wheels. then I did a blackbird, larger injectors, larger L2 headers, sharktuned - that got it 23 more rwhp and the same torque - but a bit farther up the curve.

interestingly, it consistantly beat a blown GTS that was claiming 435rwhp at the local drag strip all night long - and that was before the blackbird, sharktuning and larger injectors.

I don't claim to know why, but often numbers from aftermarket manufacturers and tuners seem a bit "off" from reality. wild HP claims have been a "thing" in the aftermarket parts world forever for everything from lawnmowers to cheby's to ferd and even pcar parts for GT3's costing thousands.

if you have the money to burn - dyno the car as is. slap on the exhaust and re-dyno. see for yourself. it'll be what it will be. but don't beat yourself up if it doesn't do much for real performance or live up to the claims.

keep in mind - if you do make the car substantially breathe easier/better, you'll need to adjust the mapping on the chips to match whatever it is you did or it'll run lean in some spots cause the LH can't compensate much more than for an altitude / temp change on it's own w/out retuning.

also - even 40chp gets cut down to 25/28 or so at the rear wheels. then you have to be able to actually feel the diff... less than 30rwhp at the wheels isn't very perceptible at these power and stock weight levels, imo. so it's prolly not worth the money unless you're doing a ton of other stuff that'll benefit from headers too (like increasing displacement or putting a blower on top)

a TC change can easily put 50lbs of torque at the rear wheels by itself at launch, btw. it's like letting the clutch out at a higher rpm on a manual car. just don't go too far or it'll kill drivability on the street. it will be very noticable.

also keep in mind, the US 928 w/AT put out 285chp w/the 5L motor. w/the AT, it soaks up about 12% of that. so that's what? about 242 at the wheels at best? it always blows my mind to see claims of well over 300rwhp on these things when they only put out 285-315 at the crank to begin with - from only an exhaust change/and or aftermarket chipset.

also, be careful w/CA smog regs. screw around too much and the smog ***** will nail you. they started requiring annual smog on my car cause some MY 928's are now on the "dirty car" list for some reason. it burns very clean, passes fine. but it also needs to pass a visual inspection each time. so if you change much on top and they notice, they could make you return it to stock and retest. major PITA.

if you really want some fun, slap on some michelin sport cups as wide as you can, make sure the kick down is working properly w/ 1/4 tank of fuel or less and go find some canyons.. it'll have all the power you need for a white knuckle ride.

caveat emptor on the rest

zoltan944

Here is one of many

85-86 had conservative vacuum advance and like all the 32v with that Hpipe, the X pipe and chips with no other exhaust mod get 300 to the wheel

Lizard928

With standalone EFI w/ EDIS-8 I put down 310RWHP and 320RW FT LBS. There was more to be had if I wanted to get that last bit out of it. But I didnt have knock sensors so I left it pretty mild.

That is on a bone stock 86 engine. I was pulling 23" hg vacuum at idle.

danglerb

Dyno rwhp seems so much cheaper and easier to get than track HP, makes it tempting. Not as much fun at the track though.


Can't say I am that big of a fan of headers on a fairly stock motor, stock 85/86 exhausts are plenty.

sharknoob

I may have misses it but did you ever get your shifting and kick down problem sorted out?
Are you sure your starting out in 1st?

OSP

yes, kickdown is all good, shifting needs some minor adjustment, thus when i finally find a shop, will have this done as well... again, does anyone know of a good shop in western new york or northern pa?

thanks

Brett928S2

Hi

I love that and so true..is it a quote or your own ???

All the best Brett

OSP

Thanks for all the input, I now know what I need to do. I will post another thread regarding finding a shop for this work...