R34 GTT Fuel Cut/Ignition Retarding?!

[Myth33]

Ok I have a R34 GTT 4 Dr Tip-Tronic coming from Japan (Yes very excited!!).

I am a bit concerned about many GTT owners who have experienced Fuel Cut and/or Ignition Retarding in the top half of their rev range. Apparently the R34 Computer is very protective and the subsequent shutdowns temporarily reduce power to near stock in some cases. It seems that Owner's have encountered this problem after installing a few simple bolt on mods such as Filter and Exhaust .

So here are my Questions:

1) Can any mechanics or owners of GTT's comment on this? Has any GTT auto owners modified their cars with these or other mods and found their car had any wierd acceleration or idling problems?

2) If anyone can recommend a quality (experienced) R34 GTT tuner in Brisbane that would be bloody fantastic!

3) With a full 3" system and panel filter what type of power gains could I expect?

Cheers

[cameron]

Hi Myth33,

Q2) Gavin Woods @ Labrador on the GoldCoast, is know as a good tuner he might be able to help you out.

Q3) Yes full exhaust system will give you gain's with inconjunction with the Pannel filter i'd expect a gain, anywere between 10 - 20kw's.... Could be more, as this depends on what exhaust system you buy.

[NJR 34GTT]

I have a tiptronic 34 with exhaust, dump, pod, fmic, ebc and unichip. In winter I hit fuel cut from over-boost on very cold mornings. Never happens otherwise and I suspect if I play with my ebc settings a little further I can completely get rid of it. Also lowering the boost will resolve the issue, as I'm running a little higher than what I'd like due to a previous tune. Otherwise I have no idling or acceleration issues.

I don't think you will see that issue with just a filter and exhaust. You WILL experience the car running rich due to the factory ECU.

Also it may be a little hard finding a full exhaust for a 4 door locally, unless you get one custom made.

[Myth33]

Gavin Woods @ Labrador on the GoldCoast

Is the Business name 'Gavin Woods' also? Just wondering so I can find a phone number/address etc.

You WILL experience the car running rich due to the factory ECU.

Excuse my ignorance but what sort of problems are to be expected with the car running rich? Poor Fuel Consumption? Would a Dyno Tune fix that?

BTW NJR 34GTT how have you found the unichip with the tiptronic?

[IanH]

You could consider Greddys E-Manage for your Auto. There's a few GTT's in the UK running them (1 has a 2530/FMIC etc and is running200-210rwkw I think). Costs around $2k to get everything done at UK prices (not sure if stuffs cheaper for you guys).

[Abo Bob]

You wont get the dip you are describing until you up the boost. Exhaust and intake will get you about 15-30 rwkw I think. I got my exhaust from Japan. The car will run rich with these mods and use a lot of fuel but a dyno tune will not fix that. I got a lot better fuel consumption when I fitted an FMIC.

Powerplay in Sydney did me a chipped ECU which gave me lots more power and got rid of the dip for good.

[Mean_R34]

You wont get the dip you are describing until you up the boost.  Exhaust and intake will get you about 15-30 rwkw I think.  I got my exhaust from Japan.  The car will run rich with these mods and use a lot of fuel but a dyno tune will not fix that.  I got a lot better fuel consumption when I fitted an FMIC.

 

Powerplay in Sydney did me a chipped ECU which gave me lots more power and got rid of the dip for good.

Interesting. My R34 GTT tiptronic runs a Hi/Low boost controller & on high boost it retards.

Bob, did you get a stock ecu that was chipped, or a 3rd party ECU?

What did it cost you all up. I feel my car has some good potential, but the retardation annoys me. Also, how long have you had this mod & what boost presure are you running. I don't wanna blow my turbo!

[Abo Bob]

I used to run 0.85 bar but now only 0.8 bar with the chipped ECU.

Basically you swap your ECU with their one for a fee. Mine was the first to get done so I got a good deal. You will have to ring them for a price. I think I picked up something like 27 rwkw with the abovementioned slightly less boost.

What you are describing is completely normal. The extra airflow causes the ECU to retard the ignition and richen up the fuel supply causing a dip in power. I guess once you get over a certain revs it assumes the engine can swallow all that air so it gives it what it needs in ignition and fuel again.

[NJR 34GTT]

The unichip isn't a replacement chip, so the stock ECU handles the gear shift logic which means gear shifts are as meant to be. I'm not really sure of how great the unichip is really because the current tune leaves a bit to be desired, far too rich. I did notice a gain in fuel economy when I fitted my front mount too. I will be getting the unichip retuned shortly with slightly lower boost and a bit leaner and am hoping for around the 200rwkw mark.

[Myth33]

You could consider Greddys E-Manage for your Auto.

Ok so far everywhere I go (in Brisbane) I get told they prefer not to tune or use the E-manage. Not naming names or anything but I've been told quote "that the E-manage software is a pain and time consuming" One workshop would charge no less than $800 per tune compared to $300 for tuning of other ECU's.

Alternatives that have been recommended were; Haltech and Microtech LT12s. Both of these seem to be rather expensive options though with the Microtech 12s fitted and tuned for $2,200.

I am sure diferent workshops recommend different products for numerous reasons such as; experience in tuning, profit margins, supplier limitations etc. Just want to sort fact from fiction at this stage and find someone in Brisbane who I can rely on to carry out quality work. The Unichip sounds like it might be an option, especially if people believe that it fixed the power dip/retarding. Aren't Unichips fairly inexpensive also? I will check it out.

The extra airflow causes the ECU to retard the ignition and richen up the fuel supply causing a dip in power. I guess once you get over a certain revs it assumes the engine can swallow all that air so it gives it what it needs in ignition and fuel again.

Feel free to correct me if I'm wrong here but I would of thought that if you open up the breathing of the engine ie; with a pannel filter and exhaust you will gain extra airflow; therefore as quoted above get ignition retarding?

Has anyone heard of this term called 'boost creep'? I am no mechanic or anything however I have been told that a greater flowing engine, causes less back pressure on the Turbo than the factory set up and thus causes the boost to rise in the process. Not trying to start a firery debate in here people, infact I am just wanting to gain an extra 20-30kw or so above the factory power (about 10%) but I would be upset to find that these simple mods are all for naught because I start getting fuel cut when I rev the engine out.

I would prefer to chip the car as well if I am going to get that problem. Just seems like a waste of time and money to me otherwise

'Mean_R34' are you running an afterarket exhaust and/or filter or do you just have the boost controller?

[Mean_R34]

'Mean_R34' are you running an afterarket exhaust and/or filter or do you just have the boost controller?

'Myth33' - exhaust is an aftermarket 3.5inch with a Nismo muffler.