rebuilt engines safe to run turbo/sc?

AaronM3 · #1 (**permalink**) 09-18-2002, 07:51 PM

Alright, I just recently blew up piston 5 and her valves.... which i just replaced. Engine has 74k on it.. its a 95 3.0L M3.... is she safe to run turbo/sc on? I seriously have the need for speed and i want to kick some local ass around here on the street .... and my baby needs some firepower under her hood. I am looking at being content around 350-400 HP ( 300ish at the wheel) ... and the rest will go to tunes and ride. But my question is will my engine handle the pressure of say 8psi or 12 being fixed up? I resealed all my other pistons and my compression is all around 200 give or take.... am i alright or do I have a problem? Also, how hard is it to install a turbo? Sorry so many questions, just entertain me please.

JCM3 · #2 (**permalink**) 09-19-2002, 02:51 AM

I wouldn't see why not. As long as the motor is is good health (compression) then I say do it. But first did you replace the parts w/ oem quality components and did they check the rods & bearings? If so then 8 psi should be no problem w/ either alcohol inj (s/c) or good front mount/ headgasket (turbo).

jderry · #3 (**permalink**) 09-19-2002, 04:09 AM

you might have to lower the compression, just to be on the safe side of things, plus, ARP head stud kit would be nice -- I believe AA's stage I gen III is around 360 at the crank....

problem is -- trust me, you will want more boost....just when you think you are satisfied, it pulls you back in..... sometimes it is better just to WISH....rather than to have...because you crave more and more....

you start thinking of ...hmm... a T61 would sound nice.... perhaps I can reach the 500 rwhp level....hehe...

Paddy Mack · #4 (**permalink**) 09-19-2002, 05:34 AM

Quote:

Originally posted by jderry
you might have to lower the compression, just to be on the safe side of things, plus, ARP head stud kit would be nice -- I believe AA's stage I gen III is around 360 at the crank....

problem is -- trust me, you will want more boost....just when you think you are satisfied, it pulls you back in..... sometimes it is better just to WISH....rather than to have...because you crave more and more....

you start thinking of ...hmm... a T61 would sound nice.... perhaps I can reach the 500 rwhp level....hehe...

My thoughts exactly

While the engine's on the operating floor, bore it out a bit, put in some different pistons and rings to lower the c/r for some room to play with later.

it's exactly what I did. My c/r is currently b/t 8.1 - 8.3. Currently running 9 psi w/absolutely no detonation worries and putting out b/t 350-360 rwhp. At some point I plan on going to b/t 12 and 14 and the lower the c/r at that point, the better. Of course, I'll need to do some other things at that point as well.

jderry · #5 (**permalink**) 09-19-2002, 07:34 AM

Manifold and head work was done while the engine was out to give a little better airflow, and it was stroked a bit. I think JE rods and pistons would be the next step if I decided to approach one bar on a consistent basis.

I know the car can safely handle 13 psi -- it was dynoed at 18 psi and a nitrous intercooler was hooked up -- but that has me edgy to do that, although the mcoupe AA has been dynoing at 19 psi with stock internals...so who knows...maybe 1 bar is safe with stock internals.

I think if I can run one bar safely w/o detonation -- I'll be happy....although I say that now.

I only run 7 lbs right now, because anymore is honestly overkill where I live and it keeps up with most cars or beats them.... what size injectors are you running paddy mack?

I have a holley fuel pump and 55 lb. injectors which I think are WAY to big. I might go back down to 42 lb. injectors, or maybe even 36 lb ones. I think my fuel consumption would improve dramatically as a result. I'm running a little rich to be safe since I don't have a stand alone fuel management system right now. I think the ECU does an adequate job right now.... I don't need to get crazy with things.

Paddy Mack · #6 (**permalink**) 09-19-2002, 08:14 AM

55?!?

Mine are 35. Out of curiousity who did your tuning and do you know why they're that big?

Like yours, outside of the SSR comp rims, mine's a total sleeper too. Keeps away the punks on the streets better that way. Dang.....still have to take the racing number off the window though!

jderry · #7 (**permalink**) 09-19-2002, 08:47 AM

everyone's jaw

drops like that. I don't think even Craig's 700+ supra had 55 lb injectors in it. Not really sure what they were thinking. It was an AA tuner that does work in NJ/NY for them and has done multiple installs. So, it wasn't just some sideshow freak ...

The ONLY reason why I would guess 55 lb. injectors were put in is because they were contemplating a HUGE turbo -- but, even then, I think 42 lb. injectors would suffice....just upgrade the fuel pump -- and everything should be fine.

It's nice having a sleeper -- although I am seriously considering the aquamist system and yanking the nitrous n-tercooler system in there. I like the idea of a water system cleaning my valves, etc. Aftercooling I don't think is as beneficial as water injection; but, that's just my thoughts. With water injection, I probably could run one bar safely...

I am also going to S/C the green bimmer -- I'd like to compare the two as far as driveability, enjoyability, etc. Right now, I'd like to upgrade my speakers and sound system; but, I am saving the money for the S/C right now.....I even stopped myself from buying the pool table...although, I am still bitter about that.....

But, the silver one is not getting great gas mileage, my thoughts are that these injectors are way to big, but, I don't want to fool with it either, its running perfect...and I am a big fan of the cliche, if it ain't broke, don't try to fix it....

So, I am ambivalent about fooling with anything on the engine right now....only maybe the water injection -- but, that's a different animal....

Paddy Mack · #8 (**permalink**) 09-19-2002, 09:00 AM

To that end, check out EBAY. I've seen some very slightly used Vortech's for just over 50% under the price of a new unit. Just last week there was a Vortec w/10k miles on it that went for $3500. You probably know all this but........if you don't plan to go over 10 PSI w/the s/c you may want to look at a Powerdyne unit - it's also much quieter.

Next year I'll be getting the WAI myself to go along w/the added boost. AA has a quality WAI unit but there's also a maker up here in KC that makes it for several hundred below theirs. For a pro it's mounted in the engine bay thereby missing trunk cd player, shorter lines, and no gravity worries. The con is you don't have the luxury of automatically washing your windshield anymore as it uses that reservoir and a slightly smaller tank. If you're interested I'll PM the site.

Full throttle · #9 (**permalink**) 09-24-2002, 11:32 AM

Quote:

Originally posted by jderry
you might have to lower the compression, just to be on the safe side of things, plus, ARP head stud kit would be nice -- I believe AA's stage I gen III is around 360 at the crank....

problem is -- trust me, you will want more boost....just when you think you are satisfied, it pulls you back in..... sometimes it is better just to WISH....rather than to have...because you crave more and more....

you start thinking of ...hmm... a T61 would sound nice.... perhaps I can reach the 500 rwhp level....hehe...

It's like a drug! You always want more and more and more and more...