My R33 Goes Faster On 10 Psi Than It Does On 12psi

[zafeniak]

Hi Guys,

I recently purchased an R33 GTS-T and I am having some troubles with the power.

When I run 10 PSI, it seems to go quicker compared to when I run 12 PSI, why is this? It's killin me!

I got the following Mods:

GReddy Front Mount intercooler

3 inch exhaust (from the turbo back)

Pod filter with Cold air intake

Splitfire coil packs

Turbosmart manual boost controller

It almost feels as though the car doesn't want to pull on 12 PSI, the power feels so flat...

I get crazy wheel spin when I shift to 2nd gear running 10PSi, but when I run 12 PSI, I would be lucky to get a little squeek outta the tyres.

I thought it might be a faulty boost controller or that I may have to re gap my spark plugs to 0.8..

Has anyone had simular problems or know what the problem may be?

Cheers

[silva33]

Its your standard ECU buddy, leave it at 10psi until you do further tuning / ECU upgrade

[zafeniak]

I've ordered an Apexi NEO (SAFC), will this fix my problem you think?

[QUICKY]

most probably the ecu richening up. but could it possibly be your clutch slipping on the higher boost?

[zafeniak]

nah, if the clutch was slipping, the revs would shoot up while driving, and they don't.

Do you think it could be a problem with my spark plugs, the gap is set to 1.0mm, should I reduce it to 0.8mm?

[R33GOD]

yeah you can do that but i dont think youl solve much on the stock ecu.

upgrade ur ecu dude. you will be fine

[BLK33T]

To some degree ... but using a piggyback style/ signal bender messes with the factory ecu's knock correction functions ... which is bad news if you get a dodgy batch of fuel and a really hot day those things are a recipe for disaster.

Best thing to do in your situation is to leave the thing on 10psi (because much more than this will markedly shorten the standard turbos service life ... 12psi is getting to the pointy end of what is considered safe with a standard turbo) and save for either a full replacement computer or a rechip/ flash of the standard ecu.

A reflash or rechiping of the factory ecu is the ideal solution for most lightly modified 33's for a few reasons.

1. It's relatively cheap (around $1000 or so)

2. It's technically a leagal mod (all aftermarket ecu's are considered a defect)

3. It retains the factory ecu engine protection functions, cold start, and partial throttle/ cruise/ economy settings.

The only real downside to all of this is that adding extra mods and tuning is generally not as easy as just tweaking the maps, it generally requires a little bit more than this and finding someone around your area to do this can sometimes be hard.

The next mods after this you should look at are a new fuel pump, high flow turbo, and a bigger set of injectors and quite possibly a Z32 AFM ... with these mods and 16~18psi you should quite comfortably see 240~250rwkw's and ear to ear smiles when you plant that right foot towards the floor

My 2 cents hope this helps.

[zafeniak]

So will the Apexi NEO fix my problem you reckon?

[zafeniak]

Sorry, wrote that last message while the post before it came up.

These skylines are really a pain in the ass to get running properly, lol...

[BLK33T]

ohh by the way what you are experiencing is called boost cut or fuel cut ... your factory ecu has a function that robs you of power when it detects an amount of air flow that is outside what it considers normal ... the only to get rid of this annoyance is to (a) lower boost until it goes away or; (b) install a piggyback, replacement ecu or reflash the standard ecu.

[zafeniak]

I thought a fuel cut is when the car jerks you forward suddenly(ie. shuts the fuel off so the car temporarilty stops if over boosted)?

Basically, on 12 PSI, it feels as though I am driving with the handbrake half up. Feels like I am running 6 PSI.

I am sure you can imagine what it would feel like to drive your car with the handbrake semi up, yep, like sh!t......

[dead32]

i fail to see a problem here your car goes harder on less boost. so leave it on less boost. you turbo/engine will love you for it

Edited December 13, 2007 by dead32

[H@ME]

It think this has been covered already in the thread, but a re-chipped/aftermarket ecu would be a safe and good mod for your situation, re-gapping the plugs will not solve your problem. GL with it man, use the advice mentioned above.,

hame

[zafeniak]

So basically, what you are saying is that the Apexi NEO (Piggy back system) is pretty much useless (due to the inherent risk of detination), and that I would need a power FC or some other aftermarket ECU?

[SevenAngryPenguins]

safc will be fine with minor mods its just a bit of a compromise to a stand alone ecu because you cant adjust the timing so you might have to run a little richer up top do a search you will find shitloads of info on safc's

Edited December 13, 2007 by SevenAngryPenguins

[green 33]

Upgrade your fuel pump, i had to do the same, now that i have changed turbo to GTRS i have same problem and today i am upgrading pump again

boost/fuel cut kicks in around the 14.2psi and you will know if you hit it, i used the apexi safc and have been for around 4yrs running around the 13psi mark, granted that my turbo did eventually let go, but only after countless races, circuit days and drift days,

Using the safc will also remove factory boost cut, so make sure you have it checked on a dyno that you are not leaning off

[BLK33T]

So basically, what you are saying is that the Apexi NEO (Piggy back system) is pretty much useless (due to the inherent risk of detination), and that I would need a power FC or some other aftermarket ECU?

^^ pretty much they are more of a band aid than anything else

[Spunky Munky]

Its because you're running less backpressure and hence giving you more power ... the more psi you boost it up to means more turbo lag... I wouldn't say you go faster - more so less lag... if that makes sense.

[R34GTFOUR]

Its because you're running less backpressure and hence giving you more power ... the more psi you boost it up to means more turbo lag... I wouldn't say you go faster - more so less lag... if that makes sense.

*shakes head* you sir are an idiot

okay im gonna drop the boost down in my cars now cause it will "run less backpressure and give me more power"

Edited December 15, 2007 by R34GTFOUR

[r33cruiser]

-sigh- dude this has been covered to death. it is the stock ecu. it has a process of RICH AND RETARD. when u go over 10psi the ecu freaks out and retards the timing and dumps fuel....hence the rich.

this results in the car feeling as tho it is hitting the wall, and is slightly jerky with a huge flat spot. twist it back to 10PSI.

safc will help with the rich problem. but it doesnt monitor or control timing etc.

GET A REAL EAM ECU.

greddy emanage ultimate controls timing.

em blue is fine but lacks the features of the emu

Edited December 15, 2007 by r33cruiser