Boost Cut Or Fuel Cut Problem! R33 Gtst Rb25

[scottish lad]

Hi Guys,

Just had the r33 dynod yesterday and man was she running rich(which i kind of knew). Guy advised me to up the boost so i went out and bought a manual boost controller which i installed.Before i put it in the car was boosting at 7 psi with the restrictor, so i set it up to boost at around 10psi which should be ok however seems to be hitting some sort of fuel cut / boost cut and i just loose all power. Someone mentioned a fuel cut defender today??? no matter what setting i put on the controller it seems to hit 'the cut'. Can anyone explain to me whats happening? and if possible how do i overcome this problem.

Cheers

James

[89CAL]

Will not be boost cut, the factory ECU's do not have provisions for this

They have rich and retard, your ECU will be seeing to high air flow (from increased boost) and seeing this as a problem and either putting it in rich and retard or cutting the engine

And if your tuner told you to wind up the boost to fix the problem then I would consider finding another tuner......

To correct this you will need an aftermarket ECU and a tune. If you dont want to do that, wind the boost down to 8psi and drive it standardish

[scottish lad]

Will not be boost cut, the factory ECU's do not have provisions for this

They have rich and retard, your ECU will be seeing to high air flow (from increased boost) and seeing this as a problem and either putting it in rich and retard or cutting the engine

And if your tuner told you to wind up the boost to fix the problem then I would consider finding another tuner......

To correct this you will need an aftermarket ECU and a tune. If you dont want to do that, wind the boost down to 8psi and drive it standardish

So basicly if you want to up the boost on these you NEED to change the ECU. What sort of ECU should i go for? Im not going crazy with the her, just looking to get nearer 260ish bhp.only put out 186bhp and was runing very very rich! was very disappointed and the guy didnt really help much! His advice has got me nowhere¬!!!!

Cheers

[paulr33]

nistune or apexi powerfc

[scottish lad]

nistune or apexi powerfc

Have you used NISTUNE mate? Think i might give them a try net week.

[paulr33]

i prefer the powerfc, but both would do the job

the nistune setup is probably cheaper

do some reading on both before you do anything

for the powerfc you can read the FAQ in my signature

[scottish lad]

i prefer the powerfc, but both would do the job

the nistune setup is probably cheaper

do some reading on both before you do anything

for the powerfc you can read the FAQ in my signature

Thanks Paul, going to look into it

[scottish lad]

so would this solve my boost problem for now at least http://cgi.ebay.com.au/R33-Skyline-GT-R-Tuned-ECU-perfect-working-order-/230602084111?pt=AU_Car_Parts_Accessories&hash=item35b0f48f0f#ht_2506wt_1139

[scottish lad]

so would this solve my boost problem for now at least http://cgi.ebay.com....#ht_2506wt_1139

shit thats gtr, guess that would be no use!

[Mayuri Krab]

So basically if you want to up the boost on these you NEED to change the ECU. What sort of ECU should i go for? Im not going crazy with the her, just looking to get nearer 260ish bhp.only put out 186bhp and was running very very rich! was very disappointed and the guy didn't really help much! His advice has got me nowhere¬!!!!

Cheers

1st, what mods do you have on the car so far? (exhaust?, intake?, inter-cooler?)

If you are not going for massive power & keeping the stock turbo with a 10psi boost setting, and you are short on cash, you can just get a piggy back signal bender like a SAFC (for cheap) & tune that to get rid of the R&R problems.

I've the usual bolt ons with a SAFC 2 & my car made 240rwhp last time on the dyno 1.5 years ago (was also only using R34 SMIC at the time, I have since added a proper FMIC) & I've no R&R problems when I floor it.

My car is also an auto, so there would be more power loss from the transmission compared to a manual.

You will probably get better results from a proper ECU (like the PFC & Nistune mentioned) but from my experience a SAFC is enough to tune out R&R problems on a lightly modified car.

Edited April 2, 2011 by Mayuri Krab

[scottish lad]

Thanks Geo,

Where do you get these piggy backs and how much are they? Could be an option at the min.

[Ad's]

People sell them secondhand on here for cheap. Mate put a SAFC II onto his rb25 and make pretty good power increase, as it's acting like a simple/cheap tune but a aftermarket ecu would be the way to go.

[scottish lad]

People sell them secondhand on here for cheap. Mate put a SAFC II onto his rb25 and make pretty good power increase, as it's acting like a simple/cheap tune but a aftermarket ecu would be the way to go.

The SAFC might be the route for now till i have the money for the ecu route. If its cheap and easy to do then why not??? Ecu can come at a later date. Just want to get her running better/quicker than she is at the moment/

[Mayuri Krab]

Have a look on the for sale section here, SAFCs pops up from time to time when the owner have done more mods & upgraded to a full aftermarket ECU, so they have no use for it anymore. I got mine for about $200ish off someone here 2 years ago.

[scottish lad]

Have a look on the for sale section here, SAFCs pops up from time to time when the owner have done more mods & upgraded to a full aftermarket ECU, so they have no use for it anymore. I got mine for about $200ish off someone here 2 years ago.

Thanks, been looking, all seem to have sold, would i been looking to get the safc 2 rather than the 1?

[89CAL]

Think SAFC 1 just had knobs to adjust rather then buttons etc but not sure

[scottish lad]

Think SAFC 1 just had knobs to adjust rather then buttons etc but not sure

Going by pictures i think you are right, anyone know for sure the difference between safc 1 and 2. Other than 1 being older and doesnt look as good!

[Mayuri Krab]

Going by pictures i think you are right, anyone know for sure the difference between safc 1 and 2. Other than 1 being older and doesn't look as good!

Other difference I remember was that the SAFC 1 only has 8 points (on the rpm band) for tuning while the SAFC 2 has 12 points.

There is also the AFC-neo (I think that what it is called, its pretty much a SAFC 3) that you can also look out for, it is the newest one in the product line & has a colour screen (& more tuning points again I think).

As for which one to get, I would just get which ever one shows up for a good price, since they are all just a basic crude tuning device & the difference between each other won't be that noticeable IMO compared to say going to a full aftermarket ECU.

Edited April 3, 2011 by Mayuri Krab

[nisn]

i hav 2 of these SAFC-2 use to run 1 on my sr20det.did make a difference,then i went NISTUNE. ...id prob sell 1. who knows how to set car,on the back of these where it sez. CAR SELECT-

[scottish lad]

i hav 2 of these SAFC-2 use to run 1 on my sr20det.did make a difference,then i went NISTUNE. ...id prob sell 1. who knows how to set car,on the back of these where it sez. CAR SELECT-

How much you looking for??