EddieCRX

What would be a safe maximum RPM for the following build
Going to run boost at between 20 to 22 pounds

Gear box is built JDM Y1 cable quaife
1st 3.166
2nd 2.052
3rd 1.416
4th 1.103
5th 0.870
FD 4.266

B18C1
Stock sleeves 81mm
Eagle Rods
CP 9:5:1 pistons
ACL and ARP hardware throughout

Stock ITR head, cams and valve train

Garret
Turbine
- Wheel: 53.85mm w/ 76 trim
- Housing: .86
Compressor
- Wheel: 71mm w/ 56 trim
- Housing: .60 A/R
Turbine clipped for more flow as the 76 trim is a bit restrictive on the 2871.

Dark_Teg

With a stock type R valve train it would most likely be pointless to rev much past 8800-9000 rpms. You pretty much need to put the car on a dyno and see where your car stops making power. If you do make power past 9000 rpms I would upgrade the springs.

EddieCRX

My concern is more the amount of boost being run coupled with the RPM's and the stock sleeves as I fear that high RPM's and higher levels of boost may be bad for the sleeves.

kyden

i wouldn't go past 8500 with your stock valvetrain.

sleepencivic

stock valve train = stock redline

Dark_Teg

I had the same fears and upgraded the valve train, and had a CNC Werx CSS installed this time around.

EddieCRX

hmmm interesting comments, I never run the RPM's above 8800rpm and right now I'm stuck with stock sleeves, which I guess is going to be a lottery at the boost level, just the combination or boost and RPM's and where to cap them for safety sake.

Turbo-LS

iTrader: (4)

If the head is stock don't rev past stock redline. The turbo isn't large enough to have a need to rev higher. It's not going to make power higher in the rev range with this setup anyway. Personally for couple Hundred bucks slap in some springs and retainers for safe measures. Stock valves will be fine for higher rpm with your setup.

wantboost

iTrader: (2)

you should only turn the motor to the point where power drops off... anything higher than that serves no purpose unless you have to rev higher so that when you change gears you're in the meat of the power band.

you should set your shift points for each gear so that the rpm drop between each gear puts you where you're making the most torque.

EddieCRX

I understand shift points and working outside the turbo's efficiency range, I've been running the turbo at 16 psi and take the RPM's to 8800 and all has been well, I know the turbo's power band should reduce as I increase the boost but initial indications are showing that the turbo still wants to make power into and about 8800rpm on this particular unit. PCP's coupled with high rpm's are my main concern for the sleeves, from what you guys are saying I need to worry more about the valve train than the sleeves.

wantboost

iTrader: (2)

As long as you don't have any issues with detonation you should be fine. a smooth increase in cylinder pressure won't break sleeves (within reason obviously). it's the sudden peaks from detonation that crack sleeves.

if you only turn to 8800 I don't imagine you'd have to shift higher than 9200rpm at most to stay in your powerband

boostjunkie757

ive heard 9200 is the end of the efficiency range for boosting on these..



i myself only run it up to stock redline, even though ive done the crower valve springs with titanium retainers...although i might bump up the redline some in the future..

EddieCRX

To be honest I have no reason to rev out beyond 8800 I'm currently crossing the line at the 1/4 at 123mph (11.57) on 23/15 H&H slicks that's running the turbo at 15 psi I want to run a low 11 or if possible a 10 with the same set-up hence why I wanted to increase boost.
I think I will change the valve train for piece of mind but I have no aspirations to go any further with the car in terms of 1/4 mile times just going to enjoy it, well maybe

tepid1

To me, RPM is always a factor of the rod bolt size/material and the valve train components.

Like others have said, I wouldn't go too much higher than stock. ~9200 max.

Turbo-LS

iTrader: (4)

Agree with chris rod bolts and valvetrain. i wouldnt even go 9200 on stock valve springs boosted.

wantboost

iTrader: (2)

Err yeah 9200 on stock springs is a bad idea. not only is there a very real valve float issue to begin with but boost pressure also reduces the effective spring rate of the valve spring so it will float sooner.

I wouldn't go over 8800 period for the sake of longevity. want to rev higher then get a stiffer set of valve springs.

boostjunkie757

play it on the safe side..



get some performance valve springs with titanium retainers before you take it past stock redline.

wantboost

iTrader: (2)

For a car that sees mostly street miles a set of tool steel retainers would last much longer... and they only weigh a few grams more than titanium at a 1/4 of the cost.

boostjunkie757

youd know better than i..