I believe our compression ratio is only about 9:1 something like that. Its about par w/ a few turbo applications I've seen (STI is around that number, GTI turbo is and I think the WRX as well).
We should be fine w/ our's...however, if you want to lower the CR a little....you can always get a slightly fatter head gasket.

 

If the compression is 9:1 which i dont know why they would make a NA car that low but you never know and you threw on a thicker head gasket then you guys are right you would be fine boosting on stock internals. One more thing you might want to keep in mind is the rods and pistons and mentioned before. The factory likes to use a silicone based piston on production cars for the reason of lowering engine noise. The problem with these pistons is when they heat up they are like glass so any detination and you will crack and shatter pistons. As far as the rods are concerned i dont think you guys would have problems until maybe 350-400whp before i would start thinking about changing them. Oh ya one other thing you definetly would need head studs and depending on what you are going to rev to you probably should think about connecting rod bolts. When you start boosting and reving high they seem to want to do a little stretching. Just my 0.02

Chris

 

compression... 9.5:1
pistons... ceramic padded for heat disapation, but cast
rods... cast but a little beefier than in the 4g94
crank/cams... forged and nice
vlvs... s/s very nice
head... 4 vlv aluminum hemispherical which is great for boosting
MIVEC... great for boosting offering an exceptional torque curve and great upper end signature

Base RRM kit... 9 psi shooting for 220-250whp but not dyno'd yet so we have no numbers to give you.

Stage 2 kit for Ralliart... 12-15psi shooting for 270-320whp, again no dyno yet so we have no numbers to give you.

The car is all prepped and production ready to go... just waiting on dyno time and tuning to be completed. Right now i can tell you the stage 1 kit is faster than a stock evo on the highway and by feel of it will run a high 13 to low 14's quarter.

 

DAMN!!!! That sounds bad *** to me.

 

Faster than a evo...HELL YEAH!!!!!

 

The stroke actually isn't that long. It doesn't run like a Honda (VERY short stroke) but it is anything but a truck's stroke.
So the rods are cast, but good. Pistons are cast but coated. Crank/rods are forged. Looks like the engine can handle some boost before expiring.

 

Good info and maybe it is faster then a evo on the highway but in the 1/4 there is no way. Just my 0.02

Chris

 

Resurecting this thread for a sec......Two people say the crank is forged, one says the rods are and another says that they are cast, Is any one actually sure?

Also, I was reading the manual for the car and unless I read it wrong (certianly possible) it showed our engines stroke only ~12mm longer than the 4g63 (88mm ours is 100mm) and the 4g94 has a 95.8mm stroke....if that is true than there should be absolutely know reason to worry about a "truck like stroke" ours is only longer than the Evo's by about the width of a average pinky finger (I'm not saying that it doesn't make a difference, just not that much of one and with a good set of forged rods it should be fine. Then again I'm certianly no expert). Also I've heard lots of talk about our thin cylender walls and it's made me curious. Our bore is 87mm the 4g63 is 85mm a difference of 2mm; now I don't know if our block is the same as the Evo block (I assume it is being of the 4g6* family, but if i'm wrong let me know), but if that is true that is a huge overbore that is .0787 inches. Still the question would remain not how much was taken off; but how much is left. From what I can tell, boost wise we are probably limited more by our bore than by our stroke in the 4g69 engine. Still, like I said earlier I'm no expert.

 

So much for saving up for N/A parts, I'm going RRM turbo!
My buddy drives a neon sxt with an AEM intake, and weight reduction (back seat is gone...and spare tire...) He is surprised he can't keep up with my stock RA. He said he is buying an SRT-4 in the spring, he has some odd obsession with dodge.. But his efforts to be faster than me will be foiled! MWAHAHAHAHA

Good Job RRM, you guys rock

 

The 4g69 is the last gen motor that Mitsu will probably build off the family. The motor is maxed out. The same for the 4g94 . . . it's 88% maxed out. Can't really squeeze anymore bore and stroke w/o redesigning the whole block like GM did for the LS1 motor.

 

ummm...I know tons of guys who have turned their LS1's into 383's and a few went to 402. There is a lot of meat on those blocks, but yes GM desided to redesign and make the LS2.