Boost Spike With Turbotech Fully Unwound

[mrgilly]

Hi all,

I have purchased a Turbotech boost controller, whacked it in... have a query which I posted in the monster thread but I think it would be better off here. Any help would be much appreciated!

Has anyone else had issues with a boost spike to over 12psi even with the screw barely tightened? Could this be caused by the ball bearing not being seated correctly?

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Hi mrgilly,

Boost spike with a gated controller such as the Turbotech is unlikely to be caused by the controller in itself. keep in mind that there are many factors relating to the usage of boost and it differs from car to car.

Boost spike most definately will not be cause by a ball bearing not seating nicely.

In fact, if the ball is not seating tightly it will be hard to get high boost levels as it wont hold back the pressure very well. Boost spiking tends to be related to other car components and it is exaggerated differently between different controllers. advice that I have been given is that spike is very often related to modifications done willy nilly without expert computer and dyno assistance in the planning.

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Thanks for that.

The only mod on my r34 otherwise is a cat-back exhaust...

Are there any other common causes to this i.e. stock parts needing replacement etc? Is it likely my stock boost gauge is just cactus?

Cheers

[Cubes]

Mines been fine, check the spring hasn't caught on the bur some times created by the small drilled relief hole in the side of the boost controller.

I had to remove the bur in order for my boost controller to adjust correctly.

If the ball isn't seated correctly it won't make higher boost levels, it will be lazy and chances are will only hold near stock boost levels.

If the spring is caught on the bur preventing ball travel then this may cause what you are experiencing.

[mrgilly]

Thanks, I have pulled it apart and re-assembled it but to no avail, however I shall specifically check this.

Cheers

[mad082]

first of all, is the boost spiking to 12psi then dropping back, or just going to 12psi and staying there? these boost controllers don't take much of a turn to change the boost, so if it is staying at 12psi, just unwind it a touch (1/4 turn or so).

i found with mine, when it was fully wound out boost was a bit spikey, then when i wound it in a touch the boost dropped, then as i wind in further the boost rises agin. my mate had the same thing with his turbosmart boost tee.

[mrgilly]

Interesting, it's spiking to just over 12 then dropping slightly but staying high. I may try winding it in slightly to see if this is the problem.

Will try it after work today

Thank you.

[WazR32GTSt]

i have no spike running 14psi... have you tried winding it literally out as far as it can go?

[Links]

mine spikes to 10 on rapid acceleration in 2nd/3rd.. than settles to about 8psi.. if I ease the boost in.. it won't spike..

I think this is due to a rush of boost as it comes on and the bleed valve can't quite accomodate it quickly enough..

[mad082]

Interesting, it's spiking to just over 12 then dropping slightly but staying high. I may try winding it in slightly to see if this is the problem.

Will try it after work today

Thank you.

are you trying to run 12psi? if you are then just leave it there. i thought you were trying to run lower boost and that was as low as you had got it. it may be other things that are making it spike, such as the bov leaking. what exhaust setup are you running? if you are still running stock dump/front pipe then that could be another cause.

[Links]

Make sure there isn't anything restricting it.. maybe run a thicker hose so it presents less restriction to the wastegate..

[mrgilly]

I'm trying to run 10psi, it's fully unwound and I have stock everything except cat-back exhaust... nothing obvious is restricting it. If I unwind it any more it will fall out of the thread!

[AzzurrA]

i take it you're not relying on your stock boost gauge for these readings?

if you are, i suggest you get yourself a proper boost gauge and THEN tell us what it is reading.

[mrgilly]

Yep, stock gauge, hence in the first post I noted that it mightn't be accurate - you think this is likely? Is it the case that the stock gauge is fine for stock levels but less accurate when upping the boost?

[Links]

Stock gauge is good for making sure your making boost.. after that.. I wouldn't use it.. how do you know it's making 12PSI.. could be making 10psi not much difference on the gauge.. especially when driving..

Grab a boost gauge.. T it in.. than see how you go.. personally my turbo timer has boost as well.. and gives me a MAX reading which helps alot..

[mrgilly]

Well, my guess is that 3/4 up to +1bar is 10.5 psi and it's definitely above that

Thanks for all the advice, I shall investigate an aftermarket boost gauge. Shame they're a pain in the ass... can't just switch out the stock-o

[Cubes]

Stock guage.

Mine sits on the + sign and thats smack on 11psi according to a dyno's map sensor.

Smack on the +7 line is 14psi and slightly over is 1bar.

[mad082]

personally my turbo timer has boost as well.. and gives me a MAX reading which helps alot..

so does mine but i found that it is nearly pointless to use as it isn't a true indication. it only reads the max that it spikes to. so if on a gear change it spikes up 2psi above what it is actually running at you will think that you are running that boost.

[Links]

I use 2 x things.. 1 is the max to see what it's spiking too.. and than I use the current real time boost display to see what it's running when your @ full boost with load.. e.g. up a hill in 3rd.. used a video camera to record it and review it while I was tuning it in..

Also if you slowly build the boost up rather than quickly slamming the accelerator and having it ramp up - it's less likely to spike and you'll be able to see what your running with a max boost setting

Edited July 7, 2006 by Links

[mad082]

I use 2 x things.. 1 is the max to see what it's spiking too.. and than I use the current real time boost display to see what it's running when your @ full boost with load.. e.g. up a hill in 3rd.. used a video camera to record it and review it while I was tuning it in..

i started off using both but then just went to using the boost gauge. i was just pointing out that it will only show the spike max for anyone reading this that isn't that knowledgable about this sort of thing so they don't think that their boost gause isn't working properly.