What hp will blow this engine

[overlordsshadow]

88 t1 block
stock mitsu turbo
t2 rods, silvolite hyperutectic pistons
stock crank
stock ign
valves back cut and head 3 angle job

If running no intercooler?


If running mazda 323 intercooler

[show-off]

Those pistons don't like boost at all. They will pop pretty quick. I wouldn't push over 14 with an IC and lots of fuel.

[Jckrieger]

Those pistons don't like boost at all. They will pop pretty quick. I wouldn't push over 14 with an IC and lots of fuel.

What he said. I've seen those pistons crack at 15psi before. Back off your timing a couple degrees and run no more than 14psi and you should be fine. Just make sure to always use premium gas.

[overlordsshadow]

if using 87 octance what boost should be pushed?

[Jckrieger]

if using 87 octance what boost should be pushed?

Personally, I'd set the base timing to 10 degrees and run no more than 8psi with those pistons on 87 octane. I always run 93 octane because the extra $2 it takes at the pump justifies the piece of mind that I'm not going to be cracking my pistons.

[Force Fed Mopar]

I'm running Sealed Power hypereutectic pistons in my engine, over 10K on it now at 14-16 psi of boost with no problems, fixin' to go +40's and 3-bar at 18-20 psi. Mostly what will kill these pistons is detonation, if you keep the A/F ratio right you shouldn't have too much problem, but you definitely need to get an A/F gauge and keep an eye on it, if it goes lean under boost, get off it quick. And definitely run 93 oct, like Jckrieger said that extra 20 cent at the pump is worth the extra insurance against detonation.

[overlordsshadow]

I have auto meter a/f and boost gauges. Any other gauges I should get? Any other tips for engine

[Jckrieger]

As Force Fed said, you can run boost on hypereutectic pistons (I've run 18psi on some unknown aftermarket pistons) but every time I lay on the throttle I wait for the smoke to come out the tail pipe. You might want to get an EGT gage, but just an AF ratio gage should be fine.

[Mario]

Autometer A/F gauge and Boost gauge blows. I recently swapped them out in my Charger as they both read like shit. I'd opt for a Dawes A/F gauge or even a Wideband if you have the cash. For a boost gauge, get a Nordskog. My Autometer gauge reads 2-3 Psi off. :(

[overlordsshadow]

puttin in 255 walboro as soon as it gets here from TU.com. What else do I need besides intercooler, and 9yc spk plugs to run constant 15 psi boost? Also, raced a 2003 cav today, not sure if auto or man, but car gets killed until boost is made and by that time the guy has 2-4 lengths on me. Then once at about 3000 rpm and some boost just rocket, then ob cut out. What should I do?
One who needs guidance

[Force Fed Mopar]

Not sure what you can do about the OB cutout on a SBEC computer. I guess you could use a Zener diode on the MAP so that it doesn't see more voltage than than the stock boost level gives it which will keep it from tripping OB. But you'll really have to watch the A/F gauge, since the computer won't give it anymore fuel than the stock boost level requires, because it won't know that there is any more boost being made.

A better way to do it would be to have someone socket your computer(or buy one already socketed, or have a spare socketed) and burn you a custom chip for your car and setup. Not sure if anybody has really got into the SBEC computers yet though. Post in the Computer Hacking forum on here for that.

You're spooling at 3 grand?! Have you checked the timing and all on it? Is the timing belt on right? Vacuum lines hooked up right? You should have almost instant boost with a Mitsu. Did you run from a roll or a dead stop?

[overlordsshadow]

dead stop, it starts spooling and making boost at about 2000 plus but not very usable till 3

[Force Fed Mopar]

Hmm could be the computer holding the boost back until higher rpm, I guess. I bet if you Graiger valve it it will spool a lot quicker.

[overlordsshadow]

its is grainger valved. Almost not even bolted together its out so far. Lots of preload on the spring though.

[Force Fed Mopar]

Lol well knocks out that theory huh. You check all the cam and ignition timing?

[87glhs232]

You said 88 block, does that mean your running a roller cam also? If so is it a square or round tooth timing belt?

[overlordsshadow]

Im pretty sure all my timing is right, Nole Maxnimuk helped me out. I have a square tooth belt but I believe I have roller cams, the newer cam used in those engines.

[bfarroo]

Not a big fan of the hyperutectic pistons, have 4 ashtrays here from a 2.5, one with a hole in it and three with cracked ringlands, This was on non intercooled boost of about 10-12 psi pig rich. 2.5's do tend to be weaker. Granted a previous owner put a autozone crate motor in it. From what I can tell it's a Dakota block(2.5 with no balance shafts or bolt holes for balance shafts and the bosses on the front of the block are drilled and tapped) with LW press pin rods(old 2.2) and Hyperutectic pistons.

[overlordsshadow]

So far these pistons have taken 15, if boost gauge reads right, at least 12 though. Not sure of the actual hyputectic mix but hope they keep up.

[Tbird232ci]

give us a list of what all is done to your car

sounds like you need exhaust despirately

before bumping the boost, do as youre already doing, get a good fuel pump in it, make yourself a cold air intake, get a nice exhaust put on it (not just a muffler), stick a new timing belt on it, THEN worry about real mods such as boost

you can make a decent bit of power with stock boost, its all about air flow, quality vs quantity

[overlordsshadow]

Just rebuilt the motor from a donor car. New pistons, TII rods, all new bearings and seals, new belts, modded air intake so that filter is open to the air, gonna make hood scoop. Grainger valve for boost, fuel purge canister gone. 2.25(believe thats the size of 88 mitsu downspout) mandrel catless, highflow muffler. Walbro 255 going in when it gets here, should be here today or tommorow. Boost and a/f gauges. Oil cooler for turbo.

[87glhs232]

Im pretty sure all my timing is right, Nole Maxnimuk helped me out. I have a square tooth belt but I believe I have roller cams, the newer cam used in those engines.
An interesting thread to look at if you have'nt already seen it:
FAQ: Round tooth/Square tooth and how they change your cam timing (http://boostedmopar.com/forums/showthread.php?t=1348)

[JDAWG]

88 had a roller cam from the factory