Thread: 500hp SR20

Hey guys, only somewhat new to this forum and the SR20 engine,

im currently building a 500hp street strip engine, even if capable of more im not chasing huge numbers, just something scary to drive around that will blaze tyres at a poke of the throttle.

my last engine made 280rwk and ran an 11.14 @ 128mph in a stanza with a manual on 215 street slicks with at 18psi tire pressure.

ok new engine is in machine shop, i want a reliable 500hp i can flog a few times a week and it will live forever, so this is what im doing..

SR20 DET block, Dartons sleeves, Spool H beam rods, 87mm CP pistons 8:5.1, 1mm BC oversize valves, BC 272 @ 12.55mm lift cams, springs, valve guides, bc retainers, ARP head studs, ARP main studs, race bearings, new timing chain and adjustable cam gears, ported polished head, match ported manifolds, Garrett GT30/76R (may need bigger) tuned length exhaust manifold, Greddy intake manifold, 80mm throttle body, stock crank balanced with balanced rods and pistons, larger oil pick up, new oil pump,
balanced flywheel. exedy stage 3, 5 puk button clutch, 800cc injectors (may need bigger), a coil per cylinder - leads, 3inch air to air intercooler, boost 6 pipe.

all controlled from a Haltec platinum sport 1000 ECU, with boost solenoid so ECU will control boost.

Hoping to run low 10's with a manual next time around, and drive it home again.

Let me know your thoughts and recommendations anyone got something similar?

Who is sleeving the block? Are you sure they know what they are doing?

FYI those ARP main studs require clearance work on the upper oil pan. At least they do on FWD blocks. Not sure on RWD blocks.

Garrett GT3076R is a tad small for 500WHP but is fine for 500HP. Tuned length turbo manifold is not required.

What do you mean by larger oil pickup and new pump?

Your clutch choice sounds excessive for that kind of torque. A 6-puck should be fine, and I would recommend a Clutchmasters kit over the Exedy kit. 800cc injectors should be fine at 3-bar fuel pressure.


We made 450WHP in the S13 with a lot less. Stock bottom end, stock cams, Greddy intake, GT3076R. It took the abuse and kept wanting more. It threw a rocker and engine got torn down and it was pristine inside. I think you'll be fine, and honestly I would save the money and complexity of sleeving the block and stay stock bore and stock sleeves. With your cams you should have no trouble getting your power goals, even with the GT3076R.

James race engines flemington, They have sleeved a few blocks, and have done a few engines for me and mates.

Yeah when they assemble the engine im guessing they will find that or maybe they clear with a RWD SR?

im after 500 engine HP, roughly 350rwkw, the oil pick up has a larger inlet mouth more for better flow if anything, and will have a whole new timing cover with new oil pump fitted.

yeah but i had another clutch in it before, was a cushioned button and it slipped a few times, i dont want slippage at all this time.

I read and heard from a few sources that the blocks flex over 400hp, weather its detrimental or not depends on the length of time it is held at full power?? not too sure, apparently caused by the gap between bores at high boost and rpm levels, i thought id avoid this happening and know the engine is capable of whatever i throw at it,

as i said this engine is more for reliability than monster power, i want it to take a beating day in day out, make moderate power and not miss a beat.

maybe over compensating with parts, but i guess you cant argue that the parts are more than suitable.

Hey fellas, just an update for those interested,

Engine is part the way complete crank is in, new bearings, Darton sleeves installed, ported head and valve seats machined for oversize valves, CP pistons get dropped off tomorrow along with Spool Rods.
manifolds are being match ported as well as manifold to throttle body, 70mm billet throttle body on its way.

engine should be good for around 1000hp, but i wont be making that.. at this stage anyway.

anyone want any details on this build let me know.

can anyone tell me if a 272dur x 12.55mm lift IN and EX hydraulic cam would be good for 500 to 600hp?

The stock cams are good for 500HP no problem. With your oversized valves, that makes things even easier. A 272/12.55mm intake/exhaust cam would be plenty good too if you feel the need. It will allow you to reach your power goals running a lot less boost (but isn't absolutely necessary). What brand cam are they? If I were you I would give serious thought to the JWT S4HL cams. I am a stock cam kind of guy, but if I were to ever get real serious on an SR20 turbo build, I would do the JWT S4HL cams for sure. They will be great on RWD SR20DET. Go look up their specs and see how close they are to your proposed 272/12.5mm cams.

I already have the new cams, a slight upgrade from the old Tomei 270/12.50mm

They are Brian Crower cams, they make pretty good stuff, valves and springs are also BC. I didnt see the point in building an engine like this to fit standard cams. i want it to breathe well with the porting that will be done.

according to Garrett, and this is a rough figure, but with the GT30/76R at close to its max output, should make 500hp @ 30psi boost which this engine will handle with no issues.

Only reason i asked was i was looking at 280/12.55mm cams but i doubt it will be necissary, the old cam was pretty mean for a turbo SR as it was.

We are quite familiar with the BC offerings. They are fine too, (often needing adjustable cam sprockets to get the most out of them however). I probably wouldn't have spent the money to upgrade if I already had the lesser BC cams, but whatever.

I think 500HP @ 30 psi on the GT3076R as predicted by Garrett is being a bit conservative. I don't see why you couldn't make 500HP at 20 psi with that setup. Again, I've seen around 500HP on stock cams, stock valves, and the GT3076R at 25 psi.

you may be right with the power on lower boost, the only reason i changed cams is the reason for the other engines failure was lack of lubrication which showed firstly in the no.3 lobe of the inlet cam, where it had spun on the rocker arm and worn both cam and rocker arm. I have tomei adjustable cam gears fitted and can be adjusted during tuning.

like you said with this setup it wont require so much boost to make the power a stock engine would.

im chasing reliability over power but its always good to know the engine will withstand major HP upgrades if i decide in the future.

Am I understanding right that you got 500chp with stock cams on s13 DET head? i didn't know stock cams could do that.