Stock Rb26 + -9S + E85

[usmair]

Not sure but have seen it on a few progress readings.. might be a temp thing

A mate said that I can have his standard valve n springs from 34 gtr rb26.. anyone know if it would fit a 33 rb26?

[usmair]

Lol whoever told yavuz the problem.. THANKYOU!

[N1GTR]

Haha I mentioned it to get any thoughts from him.

[usmair]

he is such a good guy... didnt think he would still remember me

told him the issue and he did say the problem I have is one that could occur due to valves.. although he did say that valve problems are pretty rare

he also said he had a method of determining whether it is actually the valves without opening the head!

so will def be getting the car looked over by him (not sure if i should tell PT though)

was going to call him tomorrow but he called me lol... was very impressed! should have just gone to him again lol

Edited February 1, 2012 by usmair

[Rolls]

I might have misinterpreted him

i think he meant due to the cost involved in changing springs... it might be financially better to 'do' the head (if i wanted to) seeing as we're spending $ on labour regardless

I can understand this, a full reco'd head might be better value than doing just the springs on your head. Though you'd want to make sure it was a reputable company that supplied it.

[Piggaz]

was going to call him tomorrow but he called me lol... was very impressed! should have just gone to him again lol

Why didn't you?

[usmair]

Why didn't you?

had met the PT tuner a couple of times... he's pretty switched on too

plus they have done a fair few eflex tunes and are supposebly the best with Haltechs

ah well.. whats done is done

[rob82]

From the graph it doesn't look like valve float. It's sometimes hard to tel thoughl. What total timing are you running? What other mods mods and whtere are the cams?

[usmair]

not sure about timing... cams are standard... all other major mods are on the 1st page

what sort of indications do you look for with valve floats?

[smithy85]

Not something simple like heat soak at those sort of boost levels?

What are the intake temps like before and after the intercooler?

[rob82]

Usually valve float occurs at a resonant point in the rev range meaning that the power falls away momentarily. You usually see the mixtures do weird things at that point as the exhaust valve stays open longer.

If your exhaust back pressure is high you will usually float the exhaust valve on a turbocharged car given the profiling of the inlet is similar to the exh.

Does the power stay on higher at lower boost levels?

[usmair]

Usually valve float occurs at a resonant point in the rev range meaning that the power falls away momentarily. You usually see the mixtures do weird things at that point as the exhaust valve stays open longer.

If your exhaust back pressure is high you will usually float the exhaust valve on a turbocharged car given the profiling of the inlet is similar to the exh.

Does the power stay on higher at lower boost levels?

Tuner said power isnt falling momentarily... it just starts to lose power consistently after 6300RPM... its not like it temporarily loses power then jumps back up :S

the back pressue shouldnt be an issue... its got big front pipes and a 3.5" exhaust

the power is staying similar thought! it made 317kw on 22 psi with a boost leak under the plenum from a gasket

what does that suggest?? (sorry complete noob here)

[smithy85]

Not something simple like heat soak at those sort of boost levels?

What are the intake temps like before and after the intercooler?

^^^ Is your intercooler doing its job?

[SS8_Gohan]

i guess you could also try the old, drop the exhaust dyno run check?

[usmair]

Tuner has assured me that all the bolt ons are fine

Standard GTR cooler and a 3.5" exhaust... Shouldn't be an issue

[DVS JEZ]

Shouldnt. But 10mins to drop the cat out and do a run to see if there is an improvement.

Did they say if iys knock limited or just wont make power

[usmair]

I'm sure he would have tried it already but I will mention it again

he didnt mention anything about knocking... just seems to be stuck at 320kw

[Rolls]

he didnt mention anything about knocking... just seems to be stuck at 320kw

Which makes it sound more like a flow issue, and not exhaust side as that tends to send temps up and hence detonate.

Which leaves valves, intake, leaks??, turbo, cam timing etc.

[destrukshn]

"peak power right now is at 6300... car just starts struggling to breath and loses power"

Sounds like an exact thing i had.. Drop a set of Tomei TypeB 9.15mm in. Ignore what everyone says about running standard cams and try again and you won't live to regret.

Everyone is always talking highly of Unigroup but i find the car's he tunes runs quite low power and they are only in RWD/2WD? Too safe of a tune perhaps? Who knows...

[usmair]

"peak power right now is at 6300... car just starts struggling to breath and loses power"

Sounds like an exact thing i had.. Drop a set of Tomei TypeB 9.15mm in. Ignore what everyone says about running standard cams and try again and you won't live to regret.

Everyone is always talking highly of Unigroup but i find the car's he tunes runs quite low power and they are only in RWD/2WD? Too safe of a tune perhaps? Who knows...

can you please provide further details of your situation?? even the tuner said standard cams are perfect for -9s

yeh Yavuz only has a 2 wheel dyno so readings are in RWD... he does tune them to last so they might be slightly lower in power perhaps...