Larry928GTS

Would be even more so if you had an intake with something like the "flappy" that the '87+ cars have.

anonymousagain

Hacker - how difficult was it to swap the exhaust manifolds for the 85/86 units?

Thinking with the manifold change, a little timing bump and a slightly more open exhaust, it should be a nice wake-up call... until I find the $$ for boost !!

Kevin Michael

A lister earlier said he had 10.4.1 compression. I believe my s4 is 10.1 or close to that. I just installed a 3.4 pulley on my Murf kit, turned up the fuel a bit and am running 8-9 psig right now. I have a wideband keeping me in check and it seems happy all the way to redline. I have NO intercooler as of yet. In fact I am showing a bit rich up top. I know of reliable mustangs running up to 11-12 psig with no intercooler so I said why not? If I get the fuel right I can add a couple lbs. Well its' been a week with some pretty hard rompin', and she is behaving well. I ran a 4.2 0-60 easing off the clutch to avoid spin with a 5800 rpm 1-2 shift! Not bad. I intend to add an IC soon and maybe go 10-11 psig with 30lb. injectors then I will stop. If she blows, I got a spare engine!
Kevin

hacker-pschorr

I've done worse on my 928 (master cylinder, cam tower removal come to mind). It is 10x's easier to reach the manifolds with the lower cross member off. So, if you've been putting off that pan gasket, tie them together.

I wouldn't plan on 85/86 manifolds unless I was also willing to replace the entire exhaust. The pencil pipes going into the CAT must be robbing horrible amounts of power.

I did have to make a few of the bolt holes larger on the manifolds for them to just slip on. Other than that, it wasn't a bad install at all.


Kevin,
Please get an intercooler on there. Right now we are driving in cool conditions. Come july your car may feel fine, but hotter intake temps = bad things man.
You will never heat soak an air / water IC on a street car. I would take a very long time of WOT driving to heat soak 3 gallons of water in the Murf IC setup.

sweanders

Lots of talk of boost and fuel, how about ignition?

Sharktuner?

Kevin Michael

Sweanders, Kenne Bell boost-a-spark

sweanders

Never heard of that! How does it work?

sweanders

Ok, read about it. Does it work IRL?

Wade T

Many MKIV Supras over well over 1200rwhp. Most run a GT47-80 or 88 sized turbos. Some are 3.0L and others are stroked to 3.4L. They typically make that power with ~40psi of boost. Remember, the bigger the turbo the less psi you need to make it to a certain hp range.

Kevin Michael

Seems to be ignored by the traditionalists, but Kenne himself swears by its' capabilities. Just turn it up or down inside the car for the best setting and it will do its' thing when under boost. Sorta generic but works very well and it is simple. I may try the boost-a-pump next with my 30lb injectors.

hacker-pschorr

Kevin,
What plugs are you using?

jyoon

don't think you can just keep adding boost as long as you add fuel. boosted cars come with forged pistons for a reason. don't think for a second you can run the same boost numbers as a supra or any other factory turboed car. the stock 944 turbo only runs around 12-13 lbs and comes with forged pistons. if you run much higher than your 8-9, i suspect something bad will eventually happen to the stock bottom end. but, those are some great numbers and that car must be very fun to drive.

123quattro

In my experience, boosted cars usually have piston failures. Too much knock from too high in cylinder temps and either the rings lands get broken out, or the top outside edge of the piston melts. Bottom end failures are usually from a missed shift or oil starvation during extended high lateral cornering.

V2Rocket

Maybe they should make sodium-filled pistons too :P

Aj928

If a boosted car, say a 928s4, is in the 10 range/intercooled, has proper fuel flow, timing, air-fuel mix (JDS SharkTuned), uses 96 octane and is well maintained...how many miles do think it will be before engine failure begins ?