BowTieBlood

If I was planning to set up for a single turbo on my C4 in the future future, but do engine mods within a year or two, what should I do to reinforce the engine in general to stand up to the extra boost? How much do I need to lower compression? I was thinking maybe a turbo at like 10 psi or 12 psi, def. nothing more than 12 psi. Is our compression 10.5 or something like that stock? If it was at 9 I could push decent boost right? Thanks for any advice comments, etc. Did you guys modify your engine first or do it all at once?

Bruce

under boost of 10-12psi will last you a few hrs if your are lucky. Build the damn motor first save your self later trouble

Bruce

Baldturbofreak

well, as long as it's properly intercooled and the tune is on the safe side 9 psi is feasable. I did it for a month or so. Just remember, with hypo pistons it only takes one mistake. Just ask my poor Lt1's ring lands :lol: As bruce said go the safe route and build a solid foundation-then go for the boost.

Baldturbofreak

Just use a set of speed pro -22cc dish, forged pistons. good rod bolts or upgrade the rods with eagles or the like. The crank is ok up to about 5-600hp or so (due to the soft nature of boost) But.. how long it will last at those levels is anyones guess. a decnt 1 pc rear main chevy steel crank will do fine. A 4340 non twist forging will deal with all you can give it.
Shoot for 9-1 or so. aluminum headed reverse flow lt-1's with a good coolant like evans Npg will allow 15psi or more on pump gas(intercooled). throw in some smg water injection and were talkin 20+ psi and 800rwhp. All for Around $10,000.

SurfnSun

boosting a stock motor is like a stick of dynomite with a really really short fuse. Build it first. :yesnod:

Baldturbofreak

:iagree: Got that right bro. Like I said, just one mistake.......

BowTieBlood

How would y'all compare the dangers in boosting with a weak supercharger vs. boosting with low boost on your common turbo? Obviously same potential problems, but could I safely run like an 8psi procharger on the stock motor as long as I don't get on it until I build it up maybe 5 months later to a 350 or 383 with 9.5:1 or 9:1 compression??? If I put the charger on first, could I survive for a while? I'd say there would probably be a few road trips to and from Austin and Lubbock but that's just cruising at like 70mph.... I could easily avoid any hard launches 90% of the time. I'd have to take it easy ont he drivetrain as well as I haven't gotten deep into modifying that either yet.

If that answer is NO, which I'd understand completely :lol: about how much do you guys think it would cost to build up a 383 w/9:1 compression??? Pistons/rods/guideplates/spring/cam/heads (maybe stage "2"?)/1.6 rockers/crankshaft/30#injectors/fuel pump/52-58mm tb................. would all of that be sufficient enough to hold up to like.... maybe 12-15psi in the future? (of course build quality and brands of the parts etc. will matter, but let's say irrelevant for now)

Some prices I kinda pulled off a few sites put me around $4,000 + crankshaft + labor......... sound about right???? How much for the additional you guys think, and would this car be OK to drive around as is or am I going to feel weak as hell on the pedal?

Thanks again. :cheers:

SurfnSun

Here's my take on why it won't work....

First there is no "common" turbo for C4s. Youre talking about mocking up a system. Not something that has been R&D'd for sale to the public. How will you handle the tuning phase?

Second, say you do run 8psi on a stock bottom end. What if you get a bad load of gas? one time freak wastegate hangup, vacuum line crack....youre going to end up boosting thru the roof and walking home. Or you get some boost creep in a high gear...done.

To build a bullet proof bottom end the parts are going to run at least 7k + labor. I had put together a price list one time for build a monster short block for my car. Parts alone came to almost 10k if I recall. FWIW Callaway charges 19k for the TT shortblock should you blow your motor. :eek:

Baldturbofreak

Yep the wastegate line cost me my stocker.
Guys I just bought a scat 4340 1pc 3.75 crank and 6.0 eagle L19 (rated to 1200hp) for only $938 shipped!!!!!!!!

SurfnSun

That'll get ya every time :thumbs: Thats like a boost controller with no control :lol: