sr20 block

[mjjstang]

I have searched and can not find the answer. I know how much boost the stock sr20 can handle but what is the max boost an upgraded SR can handle SAFELY (bigger turbo, pistons rods ETC.)
thanks

[andrave]

2.2 liter stroker uses the stock block down in austraila and makes somewhere around 600 hp, I think its closer to 700 after nitrous.
come to think of it, I think that stroker kit uses sleeves.

[mjjstang]

anybody know without sleeves.

[uiuc240]

the stock SR block uses iron sleeves (most aluminum alloy motors do too).

the main deal is that above about 20 psi, the stock head gasket starts to give up. and Greaser found that above something like 25 psi, the head bolts tend to allow too much lift.

as posted, though, huge numbers have been seen with an SR...however, I would seriously consider what you plan on doing with the motor at those levels. a 600 hp SR is *not* going to last very long between rebuilds. that's 300 hp/liter!! if you want a car that will go insanely fast in the straight line, start by looking for displacement. if you want to make power "SAFELY"...keep the levels around 350. This is well within the range of happiness for the SR, and people make this kind of power all the time.

a 600 hp SR with a T78 (for example) is going to make all its power way up high, and then it's going to poop out on you about once a year i'd imagine. even with heavy duty parts.

Eric

[mjjstang]

so with lets say 400 horsepower to the wheels with upgraded gasket, bolts, and probably internals and such, plus more boost and stuff to get it to 400 hp, what kind of quarter mile times am I looking at with the sr20 also would 400 be safe. Thanks

[andrave]

if you have the cash, build it up slowly and you will find the limits of the engine.

[Kookaburraz]

Greaser's head only lifted at the 457hp level because one of the studs went soft while torquing the head down (meaning it had begun to strip, and it was nowhere near full strength).

Scott in florida is putting down 437 to the wheels on a completely stock block and stock headgasket SR. It's been running at over 400 rwhp for about 6 months now. Keep in mind that he's a tuner, and has full access to a dyno; the tuning on his car alone has to be for $4-5000.

[uiuc240]

you're right, Kookz...I forgot about that situation with Greaser.

But we do seem to agree on one point:

350-450 hp (I'll agree to the range) is feasible. 600 is going to require major attention.

400 hp at the wheels is going to get you down the 1/4 mile with a quickness. Main problem will be gearing. With that kind of power, 1st is going to be lame-o-rama. I'd bet you'd go faster with a lower final drive.

there are calculators online for computing 1/4 mile times...Google for them. Then put in your car's weight and the HP you want...voila!

Eric

[andrave]

IF you wanted to increase the final drive, a 300zx TT rear diff has a higher (numerically lower) one...

[uiuc240]

but it's an R230 diff. no good. the J30 LSD is 3.92:1...and there are a couple of JDM diffs that are somewhere around 3.69:1...can't remember which though.

Eric

[mjjstang]

LSD and beefy tires would help a bit though.... Right

[uiuc240]

Yes. Bigger tires effectively lower the final drive. It won't show on your speedo, but you'll be traveling faster in each gear at the same engine speed.

Eric