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 [email protected]

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 [email protected] 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
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 [email protected] 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.

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

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 [email protected] 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 ?

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

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.

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

    • If they can dyno them, get them dyno'd, make sure they're not leaking, and if they look okay on the dyno and are performing relatively well, put them in the car.   If they're leaking oil etc, and you feel so inclined, open them up yourself and see what you can do to fix it. The main thing you're trying to do is replace the parts that perish, like seals. You're not attempting to change the valving. You might even be able to find somewhere that has the Tein parts/rebuild kit if you dig hard.
    • Can you also make sure the invoices on the box (And none exist in the boxes) are below our import duty limits... I jest, there's nothing I need to actually purchase and order in. (Unless you can find me a rear diff carrier, brand new, for stupidly cheap, that is for a Toyota Landcruiser, HZJ105R GXL, 2000 year model...)  
    • Murphy strikes again! Nothing at all would have gone wrong if you had the tool kit in the car! You'd have just found the clamp loose the next time you went to touch it...
    • I have been being VERY quiet about what you're alluding to, as it is something that ticks me off... The number of cars from factory that run coil overs is HUGE! Most of them these days do... The other part that annoys me, is people saying "Well all the incabin adjustable suspension is illegal by blah blah blah"... If that's the case, then why can I buy a car brand new that can do it if, FULL STOP in cabin adjustable suspension is illegal...   Also, I could just chuck some aftermarket shocks in my car, throw the stock springs on, after my blue slip, dump my super low springs back in. Same shock and spring style setup... Hell, they could also be the same colour springs etc.     I'm voting, BlueSlipper didn't want to touch the above car for some reason. Whether it be some sort of bias against the car, the owner, them maybe having previously done dodgy shit and now they're being super careful in case they get slapped in the face by the Gumbyment again... Find a new blueslip place.   And can confirm as you had said, yes there are holy bibles of vehicle heights, and all sorts of other suspension stuff. Heck your run of the mill mechanic, and tyre shop has access to all of that stuff. It's how they do wheel alignments...
    • Funny story Heading to Sydney this morning on the HWY there was some slow traffic, so I gave it the beans and midway through my overtaking "power run" I lost all power It seems that I missed a hose clamp,  and the MAF and filter went WiFi To make this more problematic, the little tool kit that lives in the boot, is sitting in the sun room at Goulburn......LOL Luckily for me I found a bit of steel on the side of the road that could be used like a rusty and bent flat head screw driver to tighten it up enough that it got me into Sydney, it is now all tight like a tiger with the aid of a 8mm socket Note to self: Use my brain and double check stuff, and always keep that little tool kit in the car for when I have a brain fart
×
×
  • Create New...