R33 Boost Spike At 4500rpm

[dezz]

Ok guys heres the problem...

Ages ago when my car was stock, I did the high stage boost mod found in the DIY section (constantly grounding the solenoid to override the factory low/hi boost mode of 5psi and 7psi after 4500rpm)

As far back as i can remember, it worked just as it was supposed to, and saw 7psi constantly.

After fitting my exhaust, I got the common ~2psi gain, and the car would boost to 9psi with nothing other than a full 3" exhaust (no boost controller)

A while ago now I noticed it was spiking to ~11psi at 4500rpm, just like the standard solenoid used to do with the 5/7...

I thought fitting a boost controller (the manual JRD one with the massive thread on SAU) would fix it, as it completely bypasses the stock solenoid

We put mine on, and got it to hold 9-10psi...

My problem is, that even though i had the low/hi boost thing disabled before having the controller put in, my car is still spiking at 4500rpm!

now the problem is, that it will spike to ~12/13psi after 4500rpm.

Was hoping it was fixed with the installation of the MBC, but now its 9-10/12-13!!!!!!

im obviously not driving flat out atm so it wont hit over 10 anyway, but I need to fix the problem so that i dont kill my stock turbo with going over 13psi, and so that I can move forward mods wise...looking to fit fmic/pfc and tune shortly, but cant do that with this current issue.

Anyone got any ideas of what might be causing the spike, which happens SPOT ON 4500RPM, even though the solenoid has no hoses going into it, and is completely disconnected at the plug anyway...?

Sorry for the long winded post, but it should have all the neccessary info on whats happening for someone to take a stab at diagnosing...

Thanks in advance

Dezz

[Bliksem]

probably linked to the cams changing over

[dezz]

probably linked to the cams changing over

So why am I the only person having this problem?

Its a pretty big problem when you think about it....12psi being the limit of the stock turbo...and thats with a fmic or decent smic...I'm still running the stock cooler, hence setting it at 9psi...

Also the fact that with this spike, I can't really get my car tuned (once i get my fmic and pfc) as it'll spike to ~13psi once they pass 4500rpm, which they will obviously do to tune it...

Surely there's a way to fix this

[13thracer]

you may be having the same problem as myself. i started a thread about 2 days ago under the title "boost creep" some may be related to your issue so have a read

[dezz]

will do. thanks

[mad082]

hey dezz, so you are the one justin was talking about. it may be due to your dump pipe. they will slightly move on the turbo after time. it may have twisted to 1 side slightly and now is fowling the wastegate or the wastegate airflow slightly, and then when the cams change over (and it starts dumping more air out) it is causing the boost increase.

my advice would be to take the dump pipe off and make sure the wastegate is opening properly, and look for evidence of it hitting the dump pipe. if it is then grind the hole bigger on the dump pipe.

[dezz]

Justin told me what you think it is

We're gonna be trying some thing tomorrow to check if its hoses etc...bypass the boost controller...

if that doesnt fix it, then we'll check out the dump pipe like you've said.

Thanks

[paulr33]

yeah skip the controller completely and it should just run of the actuator

if it still spikes to 13 then the actuator is mashed or the rod is mashed or the gate is fouled like mad said

[nuffsaid]

Maybe get a good EBC and that will prevent spiking?

[smurf80]

Maybe get a good EBC and that will prevent spiking?

Yeah but the actuator shouldnt be spiking like that if everything is working properly. I get in there and check everything out first

By the way I hear this problem only happens in 40th Aniversary model R33 I think you should swap with me.

Just jokes mate im jealous!

Cheers

Chris

[dezz]

lol i was actually saying to my mate yesterday...they must've played around with the 98 model R33's to make them more interesting/challenging

[West]

Boost spike? To 13psi? Psss, more powah. I ran 14 constantly on my old 33gtst for three years .

Dont be a tight ass, get a EBC Micheal man .

[dezz]

If the controller was the problem, I would...but it doesnt seem to be the case...

[TurboX]

I could tell you the problem, but you might as well buy the latest HPI and learn about it like I did

[dezz]

or, you could tell us all...

[paulr33]

if you didnt have the problem before you fitted the controller then its the way the controller is fitted, or at least logic would say anyway.

i cant see it being that actuator at fault, if you remove the controller does the problem go away ?

[dezz]

I had the problem before the controller was fitted.

Update on this...

Justin and I pulled it all off today, took off the controller, and took off the heatshield to check out the dump pipe etc...

We basically took it all off, looked at it for a bit, and then put it back on....lol

Took it for a test, and it holds 9-10psi all the way (tested to about 6000rpm in 2nd)...so confusing...lol

However, the day we fitted it, I could swear it held 9-10 when we first tested it...but a day or 2 later I noticed it spiking...so although it seemed to work today, i'll get excited if its still holding in a day or 2!

[siddr20]

I have the same problem i believe its your manual boost controller.

Mine use to spike to 1 bar..

Have turned it down a fair bit, and only spikes to .9 bar which is alright. Car can handle it..

Btw there are no hoses going to your stock soleniod??

But now since playing around with the boost, i have to many flat spots in 2nd.. guess i need a tune!!!

edit:

I got my car dynoed at dyno day, and they said my car was running a little rich.. Which is gd news since mine use to spike a fair bit.

But i have just turned my boost down a bit and doesnt spike at all past 1 bar.

SO my suggestion is just turn the boost down a little..

Edited September 18, 2006 by siddr20

[dezz]

Stock solenoid has no hoses going to it, but its unplugged anyway...its as good as off the car.

I'll update in here after a day or 2, when I can see if it was just a once off thing again, or if its going to last this time..

literally all we did was unplug it, take off the heatshield, look at the turbo/dump area, and i moved the rod that goes to the actuator with my hand....we did absolutely nothing else lol

[Munkyb0y]

dezz, i suggest checking ur boost in a higher gear, like 3rd, pref 4th if possible. u get a more accurate reading there. but i guess if the spiking was apparent in 2nd before, and it's gone now, u should be ok.

so what was the prob anyway?

edit: nevermind, it's a mystery, lol.

Edited September 18, 2006 by Munkyb0y