I finally got my 4v motor. I am rebuilding the bottom with forged crank rods and pistons. I was going to use crower stage 3 cams and run around 18psi of boost. My question is....Is it possible to make 750-800rwhp out of this motor? What will it take parts wise to acomplish my goal. It has the B-heads 96-98 that I plan on keeping because of cost reasons but I am going to port them. I was also going to retain underdrive pulleys, a bigger T-body and MAS. I will eventually purchase turboinovations.com headers and move my turbos up front getting rid of the remote set up I currently have on my 2v. What else is there that I can do to raise the power? Is 800hp reachable? or am I living a pipe dream.

 

Chris Escobar's True Street 1986 SVO with Incon twin turbo 4.6L DOHC (B heads) runs 9.20s.

Chistina Eldert's drag radial LX with huge single turbo 4.6L DOHC (B heads) ran well into the 8s, IIRC.

Rick Doern's Vortech supercharged 4.6L DOHC (bone stock, used longblock from a Mark VIII, stock B heads, with a Cobra intake) ran low 9s until the valvesprings went flat.

Talk to Lamotta Performance here in Orlando (specifically, Longwood, FL).

Mark

 

B-heads respond well to boost! Your goal is well withen reason with a well prepped SB, even with bone stock B-heads!

Ken

 

Easily doable. A GTS76 would do that without issue and would build boost nicely.

 

All it takes is a motor that will take it, two turbos and about 20 pounds of boost.

I've got SHM stage II ported heads (not recommended to anyone else), crower springs, stock cams, and twin MP 60's. (built bottom end.)

I'm still amazed by the kind of power you can get out of these little 281's.

 

How much power did you make?

 

I would also make sure that the cams you are considering work VERY well for the setup you decide on. I only say this because I've seen soo many people buy stage xyz cams because they're huge and sound badass and then watch them fight to get what others seem to get with ease using the stock cams. I've seen a B head car make 800 plus rwhp on stock cams! Matter of fact I seem to remember the cams that came in the early cars being a sought after cam for boosted 99up cars....

For heads - like everyone else has already said, you can make a ton of power with B heads and their design actually favors gobs' of boost. I would say the b heads really shine in turbo applications more so than the other stock heads really. Make sure your manifold is setup to support the power and/or you have an aftermarket manifold that will support it and you will be fine. I personally wouldn't spend a whole lot of time looking for a big flow gain thru port work on these heads. I would get a GOOD valve job by someone who is a real pro with the 4v design and other than that I'd clean em up a bit and let em have it.

my .05.. lol

 

adv dur. 262 Lobe 262 276 Valve 276
dur at .050 216 Lobe 216 234 Valve 234
gross lift. .527 / .527
114 center line
Would these cam spec work well on a turbo 4v?

 

That lift seem way to high. More work than it is worth to get the spring cups machined, springs etc.

Use the stock cams, save yourself $1500 put that towards springs and a good valve job and bowl work. My heads picked up 43 cfm, and velocity with bowl work and a valve job. Add about 20lbs of boost and you will be there.

 

I'm jackstand racing, since my car is still on jackstands.

I do know someone running twin 57's who made like 780 on less than 20 pounds.

I expect to be in the mid 800 hp range with twin 60's and a Snow Meth kit.

Also, keep the stock cams. They're some of the better cams to use for a turbo setup. It'll also save you about 1000 bucks, plus labor.

 

This mark VII motor was made in the latter part of 1995 I was told that it had the same cams that come in the cobra mustang of 96-98...is this true???? I wouldnt mind spending the money on cams that is not the issue I just want to make sure I reach 750-800hp If I should keep these factory cams does anyone have a factory spec on them so that I can at least degree them in?

 

Also what should I set cam timing at?

 

What exhaust housing A/R are your turbos?

 

They're t3/t4 Master Power hybrids.

I'm pretty sure they're .63 AR, but I'd have to double check.

 

I'm running two of these. (5 bolt flanges, not 4)

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The intake cam is different

 

Cool. Thanks. You should make some great power.

 

Definately use your stock cams. The B-series cams are good enough to get you where you want. Turbo motors dont like a lot of overlap and most aftermarket cams build a lot of overlap in to there design to draw more air into the cylinders. This is great for n/a motors but on forced induction all your doing is sending the boost right out the exhaust port without filling the cylinders. Sorry to babble but anyway the stock cams are better.lol..good luck. sounds like a kick ass set-up.

 

And, on a turbo setup, if the exhaust backpressure (between engine and turbo) is higher than the manifold pressure, then during that exhaust/intake overlap, the greater exhaust pressure can actually overcome the incoming boost and head up the intake runner for a very small amount of time or, at the least, prevent any manifold pressure from entering the combustion chamber for a small amount of time (until the exhaust valve is closed). The same can be said for the residual amount of exhaust in the combustion chamber after the exhaust valve opens and before the intake valve opens, but this has a much smaller effect.

Mark

 

Those are the same turbos that I have. Will those make 20psi on a 4v. I have 2 of them on my 2v now but when I switch to 4 I would like to use them but run 20psi....????? I am also nervouse about the fuel system.