Jump to content
SAU Community

Recommended Posts

Hi guys. Please help me here any advice would be appreciated. This was my set up: RB30det block honed out to 3.2L< forged rods and pistons, port and polished rb25 head, stock cams and cam gears, bosch coils, cheap s*** GT45 turbo and waste gate, top mount manifold, greedy plenum, 80mm throttle body, 800cc injectors, jun oil pump, microtec ltx12s ecu. Was running perfect at 450hp at the wheels tuned by dyson rotary.

That's how i bought the car:

Now i stripped the rb25 head off and replaced it with a r32GTR head from spool import. CNC ported, Good valves(not sure what type), HKS 282 cams, tommie cam gears, Turbonetics GTK1000 turbo, Turbonetics waste gate, 6BOOST top mount manifold, STANDARD GTR PLENUM ( not sure if this is a let down), sard fuel rail, sard 820cc twin spray injectors, One in tank bosch fuel pump that feeds to a catch can with 2 bosch 040 taking fuel from catch can to fuel reg. Eboost2.

So that's a list of what i have added to it. It now only makes 430hp at the wheels on 24psi and runs like shit. where or what have I done wrong. Or what have I left out. Maybe it's my tuner. Any good tuners that are recommended around Brisbane or gold coast Please let me know as well.

Thanks for your help. And please email me at b.n.manteit@bigpond.com.au

Thanks

post-40332-1245075213_thumb.jpg

post-40332-1245075237_thumb.jpg

post-40332-1245075278_thumb.jpg

have you got anyway of looking at the map inside the microtech? swapping from a microtech to a vipec (or anything) is not going to fix your root issue as the ecu swap wont make any more power if the microtech is tuned properly (Granted a vipec/LINK is a better ecu though).

If you do have the ability to view the maps feel free to take screen grabs of the timing curve and boost compensation curves and email them to me info@statustuning.com it will soon be obvious if it is tune related. Another thing to check is cam timing, was it dialed in properley? or just installled at zero? ive had a few aftermarket cam gears be up to 12 degees out and then when the workshop does the install they guess the best cam setting without properly finding zero (3degrees advance on the intake and 3 retard on the exhaust seems to be a favourite) the cam timing is way out.....

Edited by URAS
  URAS said:
have you got anyway of looking at the map inside the microtech? swapping from a microtech to a vipec (or anything) is not going to fix your root issue as the ecu swap wont make any more power if the microtech is tuned properly (Granted a vipec/LINK is a better ecu though).

If you do have the ability to view the maps feel free to take screen grabs of the timing curve and boost compensation curves and email them to me info@statustuning.com it will soon be obvious if it is tune related. Another thing to check is cam timing, was it dialed in properley? or just installled at zero? ive had a few aftermarket cam gears be up to 12 degees out and then when the workshop does the install they guess the best cam setting without properly finding zero (3degrees advance on the intake and 3 retard on the exhaust seems to be a favourite) the cam timing is way out.....

Thanks trent. I belive that the cams are left on 0 and they havent touched them. But ill double check that. And ill get back to you with these graphs. Thanks lots for you honest help.

  TiTAN said:
why did you retain the RB25 cam covers? and 450hp seems a bit low for a GT45.

With the cheap chinease GT45 it was running 20psi and making 450. Now with what i think is a better setup its only running 430 on 24psi

  URAS said:
have you got anyway of looking at the map inside the microtech? swapping from a microtech to a vipec (or anything) is not going to fix your root issue as the ecu swap wont make any more power if the microtech is tuned properly (Granted a vipec/LINK is a better ecu though).

If you do have the ability to view the maps feel free to take screen grabs of the timing curve and boost compensation curves and email them to me info@statustuning.com it will soon be obvious if it is tune related. Another thing to check is cam timing, was it dialed in properley? or just installled at zero? ive had a few aftermarket cam gears be up to 12 degees out and then when the workshop does the install they guess the best cam setting without properly finding zero (3degrees advance on the intake and 3 retard on the exhaust seems to be a favourite) the cam timing is way out.....

whats a Link ?

  monty_r33 said:
It now only makes 430hp at the wheels on 24psi

At what RPM?

My guess is tuning, that's where I would start looking. Post up the dyno graphs with A/F ratios is a good place to start.

The 282 cams are bit long in duration for an RB30, unless you are intending reving it to 10,000 rpm of course. which is not a good idea with a standard crank.

The standard GTR inlet won't be the problem, most certainly not at 430 rwhp, maybe at 730 rwhp.

How's the blow by? To get 3.2 litres (rounded) the smallest bore size is 88.2 mm (2.2 mm oversize) which is rather large for an RB30 block to handle, 87 mm (1.0 mm oversize) is the most I would go. So it may pay to check the leak down at 3 or 4 piston heights just in case the bores are oval.

What the exhaust like? You shouldn't need anywhere near 24 psi to make 430 rwhp, maybe it's choking the tubine, pumping up the boost and killing the power. Easy to check, turn the boost down to say 19 psi, if it still makes around the same power on the dyno, then drop the exhaust for one quick power run. That'll confirm whether or not the exhaust is the restriction.

Since it is running a Microtec my guess is it has had some work done on the CAS, Mictrotec's don't like the Nissan CAS signal much. You can check the trigger accuracy with a timing light, just make sure that you can see the igntion advance mapped in the Microtec actually agreeing with the timing marks. Try it at 1000 rpm increments up to say 6,000 rpm, if it's accurate then there is a good chance the trigger is OK.

If the above doesn't show anything I would be surprised, the answer is there, you just have to use the right test to find it.

Cheers

Gary

I dont see any mention of valve springs. What are you using?

Also, from my experience with the lt12s you've got to take it to a tuner who's actually used them before. I got mine tuned by a rotory specialist when i first bought it, ran perfectly. Had it retuned by a big sydney workshop with a very expensive reputation and a large amount of R35's there right now. Car ran like shit.

Then back to a guy who does a lot of rotors and what do you know, runs great again.

Note, this was with the stock nissan (mitsubishi) CAS, stock plenum etc

  N1GTR said:
I dont see any mention of valve springs. What are you using?

Also, from my experience with the lt12s you've got to take it to a tuner who's actually used them before. I got mine tuned by a rotory specialist when i first bought it, ran perfectly. Had it retuned by a big sydney workshop with a very expensive reputation and a large amount of R35's there right now. Car ran like shit.

Then back to a guy who does a lot of rotors and what do you know, runs great again.

Note, this was with the stock nissan (mitsubishi) CAS, stock plenum etc

If Dyson tuned it the second time, I'd be surprised if it were a tuning issue.

Does the exhaust manifold and rear housing get red hot at full noise after a couple of runs?

Possibly as Gary has suggested is the exhaust, perhaps the cat has collapsed and is creating backpressure....

or maybe your timing belt is on one tooth out on exhaust side? Your timing might be good, but exhaust cam out by 15 degrees......sometimes silly things happen.

  N1GTR said:
Maybe i missed it, did Dyson tune it the second time?

Nah, It was more of a rhetorical statement rather than a factual comment. Wasn't saying you said otherwise but just making an observation that if he had the second tune done at Dyson, it would more than likely rule out bad tuning.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I’m not sure what happened I told them about sonic tunes free OTS tune and the next the I know .. I was booted..   To funny 
    • Yea - I mean I've seen my fuel pump which is decades old and uh, while I'm not saying this with real knowledge... but I sure get the ick at using anything in the fuel system that produced the state of that pump. Many years ago I went through multiple pumps (and strainers) before I dropped the tank to clean it out with extreme violence. I'm talking the car would do maybe 50km before coming to a halt, which resulted in me cleaning out the filter with some brake cleaner and going on my way. None of my stuff ever looked like what came out of your fuel tank. I don't think I'd be happy with it unless every single component was replaced (or at least checked/cleaned/confirmed to be clean here).
    • I'm not going to recommend an EBC pad. I don't like them. Just about anything else would suit me better. I've been using Intima pads for a while now.
    • Agreed, and in particular the earth strap that should go from the subframe to the chassis but it often broken or left off. There is a section in the R32 workshop manual you can follow for troubleshooting if you don't see anything suspicious, and depending where you are (there is no location on your user profile) you should be able to get your hands on a second hand replacement unit still if needed
    • Yeah they mention as a R34 for 2.5 Turbo...but then again thos "small" were also for R34 by that different site. But i look into it and that 310mm EBC is for R34 GTT. And by those you linked the specs are the same 🙂    EDIT: I found these on one site here: DBA 4000 series T3 DBA42304S They are 310mm...and it says are for R34GTT...are there good? EDIT2: ok they have pads too.  What "color" should i get for street use? I dont want/need some noisy ones...(and if they are not that dusty that is good too)
×
×
  • Create New...