lucas569

hondata sets the rev limit at 8500 rpm, is this a sefe level to rev w/ turbo or fi for that matter on a stock valve train? i know honda set the rev limit @ 8100 rpm for a reason. just wondering if im worrieng too much

PWRVTEC

If you are worried dont run it to that rev limit.... The difference between 8100 and 8500 aint going to be much. I run my b16 to 8300 on every WOT shift, but I am also NA and my power peaks at 8100. I have ask the same question myself, but just decided to run it.

Since you are running boost I would not go over 8300 on shifts just due to the boost pressures and longivity...

Maybe just upgrade the retainers and then 8500 should not be a worry at all.


[Modified by PWRVTEC, 1:15 PM 5/11/2002]

2K_TEG

I am not sure if this will answer your question or not, but when I talked to Joe Alaniz at Alaniz cylinder heads he told me I could upgrade my inner springs ($80) and rev to 9K on my LS head. No ****, apparently he has done it and nothing has broken. Granted, I am not going to do that, it is just a comparision. He also told me that all the titanium retainers in the world were not going to help anything. Just food for thought.

rurkster

you dont have anything to worry about unless you plan on letting your tact read 8500 for 5minutes or something dumb like that. plus stock headers on a gsr really aren't that restrictive so i'd say you got nothing to worry about.

Sonny

Doug said he said used to race his B16A CRX in New Zealand and shift at 8500 every time, all season long, and he didn't have any trouble.

I took my B16A to 9000 rpm on the dyno numerous times, but I had an ITR head on it.

Sonny

DIRep972

iTrader: (1)

what do u mean hondata sets the rev limits to 8500? i thought u could set your own rev limits with hondata! hummm, that would be UNcool if the minimum rev limit was 8500.


[Modified by DIRep972, 9:08 PM 5/11/2002]

SiRkid

so you had the same head from your b16 on there but this one came from an R
same sheet!
ive read a few places that the stock **** can take 10000 RPM( now htis isnt for long long times but if you miss shift) my friend missed a shift in his lude. said the tach went to the bottom!!!! checked everything and everything is still fine

Sonny

Well, not exactly. They are both PR3 heads, but there are differences. I checked both heads out thorougly before making the switch. ITR head has different intake valves, different springs, mild port-n-polish, but it's essentially the same.

Don't ask me why I switched to the ITR head. It's a long story.

Sonny

highmilehatch

I'm interested in revving my ls head to 9k or even 8k. So all I need to do is upgrade the inner valve springs? Will it even make any power up there with a stock head?

qwkteg125

i wouldn't trust stock retainers...i've seen too many of them crack or break, dropping a valve, & toasting the motor. imo, ti retainers are cheap insurance.

earl

IMHO, I think anyone running a turbo needs to upgrade their valve springs and retainers. What you are trying to control is valve float. Float is when the valve is no longer following the profile of the cam because the spring is too weak to hold it in place at higher rpms. When float happens, the valve can hit the top of the piston. This will cause the valve to bend and you will have no more compression in that cylinder (valve head is crooked and can no longer seal tight).
IMPORTANT..Why should you not just replace the inner valve spring? There are two measurements critical to turbo valve springs. One is the pressure when it is wide open as that is what holds the valve on the cam profile. Also there is seat pressure. That is the pressure of the spring when the valve is closed. This is also important because when you are running 20+ lbs of boost, the boost pressure is pushing at the under side of the valve trying to knock it off of it's seat. An inner spring cannot control both seat pressure and wide open pressure at the same time. Use an after market spring set made for boost.
You need to switch to titanium spring retainers for two reasons. One is that they are lighter. The lighter they are the less momentum there is and makes it easier for the spring to follow the profile of the cam (no float). The second reason is because they are stronger than stock retainers. A fatigued retainer can break which will drop a valve and destroy the engine. I'm sure Joe is a brilliant head porter but if he said only replace inner springs, it may work on his flow bench but not in the real world.
Let me say one last thing to anyone who may think that their rev limiter is going to save them. When a turbo engine is accelerating like a *****, just because you have a rev limiter does not mean that when you hit it, it won't go to a higher rpm. Momentum of the acceleration will push the motor past that point for an instant. Sometimes that's all it takes to float and break something.

ronin

i have an ls with crower valvetrain. i take mine to about 8.5k and the computer comes with the red set at 8500. my red line is set for 9k, so i can hold out 3rd on the track (ls tranny, 3rd will pull 108+ before 9k).
now i don't drive around at 8.5 or even anything over 5k. the longer you stay in high rpm, the more trbl you are asking for. stock valvetrain is usually only good for a few hundred over the shown limit on the tach. basically the heads and trannies are designed to be at a certain rpm, and you get a little cushion. the ls loses massive power after 6k or so, so why rev it to 8k from the factory? so it has gearing to work with it... everyone in theory shifts at about the same speed (mph). honda did not build monster heads on all engines, there was no need to. if you are worried, change the springs and retainers, just get type-r springs for your gsr head, or aftermarket for your non-vtec. it will def be worth the money. mine was.

lucas569

you can set the rpm at whatever rpm you want, hondata has it PRESET & DEFAULTED @ 8500 RPM. sorry for the confusion.

bruthaboost

Thanks, that was informative.

Turbo Laser

For you LS guys, your head maybe AOK but if you have a stock block be prepared to send it to spun bearin heaven...

Hondata

Yes. On my stock '90 JDM B16 a engine I ran 6 three hour endurance races. With practice this totaled about 24 hours solid circuit time. The rev limiter was set to 8600 rpm which I reached every 3-5 seconds - for 24 hours (over 10,000 times) - with no problems - whatsoever.

And this car, with the same engine made a New Zealand (and unofficial world record for this class) www.hondata.com/crx/index.html Some of you may remember the site before it was erased from geocities. I have relocated it but not linked to it until now.




Doug

tonydatyga

No and no. Well technically it will <U>make</U> power w/ a stock head...

xci_ed6

It may not be about your valve train. It may be inertail loads after intake(BDC) and exhaust (TDC) strokes where the stresses on the con rods can be higher than at the power stroke. Plus tensial stress causes fatigue (like after the exhaust stroke) while compression does not (like power stroke).

-Dustin