On rolling road my car spikes, how can i stop it because i am loosing so much tracktion. By spike i mean it comes on boost lovely but then it goes from about 220 bhp straight up tp 300ish, which means loads of wheel spin. I want to stop it as its loosing me time on track.
What sort of boost control do you use ?
what you want is an APEXI AVCR boost controller, you can set it to give you whatever boost you want at what rpm and in which gear you want.
Its a clever bit of kit but costs new abot £500 but you can pick them up second hand on the sxoc forum.
My sr20det has one with it which is good but it does take some setting up
Not running any boost control at the moment apart from the wastegate.
quote:
Originally posted by madteg
Not running any boost control at the moment apart from the wastegate.
Indeed.
When you think that the modern boost controllers will use the throttle position as one of the parameters considered when allowing the relevant level
of boost, your problem could be dealt with.
That's exactly how mine was the boost came on so strong it just broke traction! it was fun for a while but you soon get fed-up with going
sideways when you didn't intend it 
Fitted an e-boost 2 controller to mine it can do boost by gear on some production cars but on mine i use the boost by rpm function mapping the boost
throughout the rev range transformed the way the car drives knocked a second of my 0 to 60 time.
Just remembered it has an overboost setting as well so keeps your engine nice and safe!
could also eun e boost contoller again controls boost 6 settings in every gear,
this should help you but again is ££££ but not quite as expensive as the others
Is your wastegate big enough? If it is too small it could be chokieing up and so the exhaust gases can only go via the turbine.
Darren
Just a normal more basic EBC could be picked up on eBay for under £100 second hand. Even a "dawes device" mechanical boost controller could
be better than nothing.
Also what Darren said could be a factor - you can port the wastegate if you're using a turbo with an internal wastegate. Or shut that one off
and run an external wastegate. Then you can run a screamer pipe to really scare pedestrians 
They sound like a jet taking off when you start
making full boost
Read part 1 & 2 of this - it might help - there are many articles in here about practical locost solutions to boost control
http://autospeed.com/cms/A_111348/article.html
What efi are you using, megasquirt can be setup for boost control, using the extre code.
Darren
At first whats the max boost you getting?
quote:
Originally posted by hobbsy
Just a normal more basic EBC could be picked up on eBay for under £100 second hand. Even a "dawes device" mechanical boost controller could be better than nothing.
i would see what pressure actuator you have, then find a lower pressure one, then you can use a simple electronic boost controller with a gain
setting to make the boost come in smoother and more gradual.
Tom Gregory 2000 You can not make a car run less boost than the actuator or wastage setting with any boost controller, you can only increase boost.
as said above apexi avcr is the best...i do have it and you can set each gear with different boost settings 1,2 nly wastgate boost and then from 3rd
and on give it some
quote:
Originally posted by MikeRJ
quote:
Originally posted by hobbsy
Just a normal more basic EBC could be picked up on eBay for under £100 second hand. Even a "dawes device" mechanical boost controller could be better than nothing.
The Dawes/PRV style boost controllers make the boost rise even more violent than without since they keep the wastegate fully closed until a preset threshold has been reached. By itself the wastegate will gradually open more as boost pressure increases, which gives a more gentle ramp.
Note that any type of boost controller, mechanical or electronic can only raise the boost above the level that the wastegate naturally opens. If the OP is already getting the desired boost purely under wastegate control, he'll need a lower pressure actuator to be able to control it.
[Edited on 20/10/09 by MikeRJ]