Harey

Hi All, I have been looking at lots of different turbos that would work well on my RB25. So I had a few minutes spare at work and thought I would put them on a chart to do a comparison. Let me stress this is very approximate, I only took 7 different rpm readings and rounded off the power figures to at least 5kw. Its just more to get an idea of the different shapes etc. - 3071R dyno sheet was obtained from the Nistune Forum, in particular Matts own one - 3076R dyno sheet was obtained from the RB25 dyno results thread on this forum - Hiflow was off Hypergears website - PU Hiflow was also off Hypergears website - Std Turbo is my own dyno sheet Some of the inconsistencies: - boost level, generally it is around 17psi dropping off to around 15psi (except for the std turbo which is only 10psi). - speed vs rpm seemed to vary between the dyno sheets, could be the different model cars having different diff gears. So please take it for what it is.

What sort of dump pipe do you have? I know some people have issue with split dump pipes causing the wastegate arm to fail on the dump pipe and cause higher boost.

Im no gtr expert so im not sure what size the stock dump size is. My opinion is anything over 300rwkw and you should have a 3.5" exhaust. If you look through the rb26 dyno thread 90% of the gtrs over 300rwkw have 3.5" exhausts.

Thats true if hes trying to go faster on a track or twisties in the hills. However, 95% of street driving is in a straight line and sway bars and tyres wont help you (tyres only if you have too much power for your current tyres). Also, it doesnt take much skill to accelerate in a straight line

No one said that its wrong. The discussion is whether it is dangerous to the turbo to not run a bov, of course running a bov wont do any damage. I am of the opinion that bovs are not required and didnt run one on my previous car for 5+ years with no issues. Yes this is far from conclusive evidence but just my experience.

When I ordered them they asked if i wanted the grooves, I said yes That is the extent of my knowledge unfortunately. The installers said the grooves were definitely required to get my rear back to its 350mm centre of wheel to arch height. Which I think is the perfect street height on a R34. Mine were ordered and installed by Centreline. Give Chris a call, he will be happy to answer any questions.

so cars dont have to meet emissions?

The results of this I believe is what he wants. Well its what I want anyway

Good work. So as you have probably worked out the wastegate actuator on your car operates at 12psi. This is a minimum boost pressure so you cant go below it. When you introduce the boost solenoid it spikes to 16psi and above, so your boost controller is not setup correctly. Sorry I cant help with that specific boost controller.

Use this thread (I know its for the R34 but the mod guide is the same) http://www.skylinesaustralia.com/forums/Ni...Mo-t282082.html As it says in more detail: 1. Finish Exhaust off 2. Up the boost 3. Tune Also becareful with the intercooler kit pictured above as cops dont like those ones that you need to cut a hole for. I recommend a return flow cooler if you are worried about that sort of thing.

!!!!! AWESOME !!!!!!

If its just the auto and converter sapping the power, it should still be bloody fast. How does it feel?

Yes to meet emissions. A plumb back bov is the only way to ensure you are not releasing air to the atmosphere without going through a catalytic converter. No bov and you are still releasing air to the atmosphere. Aftermarket and OEM bovs have different goals so whichever one came first is irrelevant. OEM bovs for emissions. Aftermarket for noise and to supposedly protect your turbo.

Yeah would be great to see a dyno sheet to see what the curve looks like. You can normally see converter slip on a dyno.

i am assuming its an R33 turbo hi flow from your profile. the R34 has a different exhaust housing (OP6).

If you have a number of mods it can cause the stock ecu to not be ideal for the modified setup. One thing is the ecu can go into rich and retard mode which means it adds extra fuel and takes out timing. This is more under power though but as you can see will worsen your fuel economy. Custom tuning can also further optimise your afrs for better fuel consumption.

I have exactly the same setup, I was recommended the king springs also by Centreline. The website doesnt work for me??

If you are keen I would give them a call, never had much luck with car stuff via email. Sydney Kid basically just spoke to Tony from Heasmans and put some specifications in for Tony to order from Bilstein. Sydney Kid has not been on the forum for a while now. The group buys have all been closed. If you talk directly to Tony he will know what you are talking about.

In the thread below SKYPER says that he has tested a few R32 wastegate actuators and they were higher then 10psi, they varied around 12psi. http://www.skylinesaustralia.com/forums/Rb...-U-t312106.html Plus a full exhaust so 12.5psi sounds ok. As Hypergear said remove the boost controller from the system and see what just the wastgate actuator runs at.

Yeah I think people are comparing the noise of an external bosch 044 to an intank walbro which is not fair. The external bosch 044s are very noisy! I ran a walbro on my previous commodore with 250rwkw for many years with no issues.

No they definitely wont fit. The fronts will but the rears have a completely different lower mounting type. Those coilovers are for R33 GTS-T but not a GTR. The rear ones you want have a U mount bracket on the bottom (same as a 33 and 34 GTR).

I really dont understand why you think it is a boost leak?? The boost pressure looks excellent, very constant. I would class it as a lack of power and appears to be some sort of restriction. My initial thoughts are blocked exhaust, maybe a blocked cat or something. Have you tried dropping the cat and doing a dyno run?

I just purchased some sydney kid spec bilsteins for my R34 GTT. I spoke to Tony at Heasmans Steering, he knew of the group buy and had them in stock. Give them a buzz and ask for Tony: Heasman Steering 455-463 Princes Highway (cnr Railway Road) Sydenham NSW 2044 tel (02) 9557 3739 I changed out japanese coilovers for these and they are so much better for the street. They are faster and more comfortable in every situation I have tried so far.

I dont see the point of using E10 unless you have it tuned to suit. I tried it on my turbo commodore without a tune and i got considerably worse fuel consumption with no gain in power. You really need to advance the timing to make use of the ethanol in the fuel.

as above the boost seems to be holding very well. a plot of the afrs would be very helpful if you have it.