Dialling In Hks Cams (rb25)

[PM-R33]

Obviously the turbo shall be the limiting factor, it aint made for big earth shattering dyno figures, i just wanted the best possible power delivery out of the current setup. The car is bullshit reponsive and makes 1.5bar at around 3500rpm and pulls hard to redline (7500rpm), if i stomp it in 2nd gear it wheel spins as soon as it hits full boost, exactly what i wanted for a street car. I'm very happy with it and will most likely leave it how it is, only reason i'm thinking to do the MAP sensor upgrade is because it is still an issue and i don't like anything not working 100% on the car because it shits me.

Like i said, got more important stuff to concentrate on at the moment, so for the time being the car is gonna stay the way it is for a while.

Edited April 9, 2009 by PM-R33

[PM-R33]

Ah ok. Yeah the MT's are a pain when your running close to 20psi .... as i won't let a car go without the map cut enabled, so you need a small leeway before it hits max to use it.

You should measure Turbine Inlet Pressures to see where the GTRS is at, at least give you a easy indication if much more is avail...... might not be worth it until you step up in turbo.

I got 272 rwkw on a 3500 histall auto yesterday, but the 135K std head gasket finally let go. Also the VCT isnt working down low, and killing my boost response.

How did you rate your head work ? I think i'll just get a good head gasket and bolt it all back on. Just weld up the VCT to full advance, and should get bottom end back and im happy with top end.

Gary

Very happy with the head work man and one of the best prices i could find. Most places wanted double what he charged. What workshop are you at? PM me if you don't want to post it on the forum.

[rb26sedan]

Ok did the compression test and everything seems fine, all 6 around 135-140psi. Spark plugs and tops of pistons all seem fine.

The photos show that its all at TDC. The only other thing i can think of is when I installed the microtech ages ago I had to lock the timing and set it to 10BTDC. Since the belt and cams have been changed wether this has altered something, because when i put the timing light on the car last night it was no where near 10BTDC and i couldn't even adjust it so it got near 10BTDC. This might have something to do with it....

This has really stumped me, im nearly up to the point of ripping the cams out and putting the standard ones in there

with my experience when i do a compresion test on rb25 i get around 180 psi with standard pistons...

compare your compresion test numbers with other people...

i think you might have problems with piston rings

[PM-R33]

with my experience when i do a compresion test on rb25 i get around 180 psi with standard pistons...

compare your compresion test numbers with other people...

i think you might have problems with piston rings

Lol replying in a bit of an old thread mate.

Problem was fixed ages ago and no there was no problem with the bottom end.

[aerofocker]

i know its an old thread but did you ever check your woorough key and the harmonic ballancer rubber part for slippage? i hate unsolved problems!

[James_03]

old thread.

edit damn you thread diggers lol.

Edited April 12, 2010 by James_03

[r33_racer]

What exactly was the problem? Ive read through it all a couple of times, but I couldnt decipher what the exact cause was???

Was it timing belt mark alignment, cam gear setting, or CAS? Or something else i missed?

Edited April 12, 2010 by r33_racer

[PM-R33]

Why it originally wouldn't make power with the HKS cams i'm not sure. Valve springs was the main thought but I can't confirm.

After the head was rebuilt with the Poncams the cat had collapsed and wouldn't make power, once that was fixed it was fine. The HKS cams were installed in a different car which made power fine so it wasn't the HKS cams (wish i had kept them to be honest.)

The MAP sensor on the Microtech is still the 20psi model which is a bit annoying because we can't tune near 20psi. The car is also tuned very safe and rich, which doesn't bother me however. I'm not going to chase 5kw by leaning it out. Every one also says the dyno we use isn't really happy as every ones car reads lower on it than elsewhere. However I cant be bothered paying money to some other place just so I can get a larger reading on a sheet.

In conclusion the turbo is at its limit. A MAP sensor upgrade to tune it properly around 20psi and taking a bit of fuel out would help it make a bit more power, but not much. On another dyno it would probably make 270 but as said earlier, not really interested.

The latest power modification to the car are FINALLY nearly ready to be tested. I've just been having a problem with an intercooler pipe constantly blowing off which has halted the progress. Once this is sorted ill get the car ready for the dyno again and go for around 300kw and see if it holds together on the stock bottom end.

The car doesn't get driven that much any more unfortunately so nowadays doesn't get first priority like it used to. Finishing my uni studies this year and riding the motorbike every where makes modifications to the car come to a halt lol.

Anyway that turned into a stupidly long post, sorry

Edited April 12, 2010 by PM-R33

[r33_racer]

Thanks for the clarification!

Stock bottom end should be fine. Is it just your usual i/c piping misalignment thats letting it pop off? Or is it custom made and fab'd slightly off?

[PM-R33]

It's custom made stainless but doesn't have a good enough lip on one end so im getting that redone and changed from worm drive clamps to T-bolt ones. Should hopefully fix the problem.