Problem With R32 Gtst Rb25/30

[lwboosted]

hey i just finished putting my car back to standard as i am selling it.. and here is the problem i have..

basically it is a rb25 (r32 head) /30 i have put the following standard items back on the car to sell it..

- Stock ecu

- stock cam gears

- Stock injectors

- stock AFM

- stock turbo/manifold/exhaust

think thats about it...

basically as soon as i go to drive the car it struggles as soon as it gets past about 2500 rpm it makes boost but doesnt go anywhere and cant really pick up any more speed.. it is not missfiring it just bogs down n turns into a slug... i am fairly sure it has something to do with what i have put back on the car.. i am thinking the AFM but i aint sure.. any help would be good...

cheers leigh.

[CeJay]

well if you've got a stock ecu trying to run an rb30, wouldn't it tend to run crap if it hasn't been rechipped?

[MBS206]

Stock RB20 ECU should be able to run the RB25/30 setup so long as you've placed all of the RB20 sensors on to the motor.

CAS should be okay.

Correct injectors?

Correct AFM?

Correct knock sensor?

Correct TPS?

[lwboosted]

i have always used a stock ecu it was just reprogrammed to run 550cc injectors and a z32 afm.. now i put a non-chipped ecu in it and all stock rb20 injectors, afm, etc as i said before.. and yeah they are all good.. they were all working fine when i pulled them off my rb20 when i did the conversion..

Edited November 16, 2008 by lwboosted

[116.hks]

i have always used a stock ecu it was just reprogrammed to run 550cc injectors and a z32 afm.. now i put a non-chipped ecu in it and all stock rb20 injectors, afm, etc as i said before.. and yeah they are all good.. they were all working fine when i pulled them off my rb20 when i did the conversion..

I would be checking for vaccum leaks. like intercooler piping. something is upsetting the air flow meter. it sounds like

[Adriano]

Its r&r, the ecu doesn't know what is going on, there is double the airflow of the stock motor

[45ULT]

rb20 ecu's don't really get r&r.. i'd be looking more at the wiring for the airflow meter if its been changed from z32 back to rb20

[bubba]

They do get R&R and when I put my 30 in and ran it off the standard (unchipped) ecu it hit R&R pretty much straight away and was maxing the stock afm by before 6000rpm.

+1 for R&R

I had to use a CEFFIE remap chip that had no R&R to get me through until I could get a full remap done to suit bigger injectors and afm.

[lwboosted]

the wiring is all good for the afm.. what does r&r stand for? can some1 explain this a lil more.. i am going to borrow a afm of a mate to see if its that.. if not it must be this.. if it is this r&r will the standard afm be suitable or should i put the z32 back in it and change the map for stock injectors??

[bubba]

r&r is rich&retard

It is the result of the ecu's afm "over-voltage" protection. When the ECU sees more than it's set threshold of air flow, it retards the timing and throws in more fuel.

For safetys sake, I would put the z32 afm back in and remap to suit the smaller injectors.

[lwboosted]

F%$K, cant be bothered!!! alright i will get back to u on how i go with it.. wasn't cubes running everything stock with his rb30 for a while??

[Cubes]

They definitely hit R&R with the RB30.

The stock ecu is only good for limping the car around. Definitely keep it off boost.

When attempting to bring mine on boost it would fuel cut at around 2500rpm if I had 5-6psi on board.

Anything more than a pound of boost and it would feel R&Rish as it accelerated.

With the turbo disconnected/wastegate wired open it was ok with heavy throttle. Which is how I ran mine in.

Add boost and the ecu turns to shit.

[45ULT]

depends wat rb20 ecu too. From my experience the early r32 ecu's barely suffered from rich and retard they weren't that complex. Also the fact that the 30 is running a standard 20 turbo now would create a fairly substantial restriction in the exhaust.. Limiting breathing and also revs

[Cubes]

Mine was a late 92.

On the rb20 my stock ecu with the stock turbo was good for 16psi before it hit fuel cut at around 5000rpm.

Never suffered R&R.

With the stock turbo it definitely killed rev's. 4400rpm was peak power that flatlined to 4800rpm where power dropped off sharply.

Due to the R32's short gearing the car was actually quicker with the rb20det and its stock turbo even though on paper it was making 10rwkw less peak. Simply because the rb30 didn't rev with the stock turbo which is no good for short gears.

The car was VERY turbo dieselish to drive. Comes on strong then just rev's out as you feel torque drop off.

[lwboosted]

so what do i have to do to get it running ok? i want to sell the car.. do i just need to get another map put on it? or will the afm still max out? should i put the z32 back in? i want to sell the car so least expensive option!!

[45ULT]

u'll be maxing out the standard airflow meter with the 30. Best bet is put the z32 one back on and get a full retune. Depending on the tuner and how much money u wanna spend they could get by with the standard rb20 airflow meter but the tune won't be the best. At least it'll be running alot better. As i mentioned before and cubes confirmed it won't rev with the standard 20 turbo

[lwboosted]

just ran an ecu diagnostic and errors came up for..

-Cas

-Afm

-Knock sensor..

[bubba]

Technically you're not putting it back to "stock" as there is still an RB30DET in there.

We've already given our suggestions, now it's time for me to go home.

[Cubes]

No need to throw a Z32 at it as you can tune it fairly well with the stock afm even though its max'd out. Mine max'd out at around 180rwkw with the rb30. You can still push them with a fair amount of safety to 220rwkw.

Stock turbo the std afm is fine. Only 'just' maxing out.

If you want it to drive half decently make sure you have it tuned to suit.

Knock sensor ecu diag.. Make sure they are connected..

As for the cas and afm. Make sure they are connected properly. If the cas is playing up try another. Any decent workshop that deals with these cars will have one laying around for testing.

[lwboosted]

yeah think they were old faults.. i reset the computer and got 55 so all is good there.. i know it runs fine with the stock turbo as i have been defected before and needed to put it back on... looks like i am gonna have to get another tune with the stock injectors and afm.. sucks as i am wanting to just sell the car.. and was wanting an easy way around it.. i will let u know how it goes for future people..