Boost Problem

[Jsikalias]

hey guys i got the car tuned today but on the dyno graph the psi is droping from 14psi to 11psi is this normal i got a gizzmo boost controller and the setting is on 56 duty cycle and the gain is 0 would it be my wastegate and also its a highflow gcg turbo

Edited April 23, 2007 by Jsikalias

[7yphon]

hey guys i got the car tuned today but on the dyno graph the psi is droping from 14psi to 11psi is this normal i got a gizzmo boost controller and the setting is on 56 duty cycle and the gain is 0 would it be my wastegate and also its a highflow gcg turbo

What boost controler you using because it sounds like its spiking then going back to stock boost

[Jsikalias]

gizzmo

[Jsikalias]

but as i said the gain on the boost controller is on 0 so it shouldnt really be spiking it should take longer to hit 14 psi

[Green_s13]

it could be a number of things, very restrictive exhaust will do this, stock intcooler could cause, it could be the boost controller, it could also be the wastegate

[rob82]

From what I've seen of those controllers they are quite shit!! If an EBC has no PI or PID based boost control then you may as well just use a bleed valve. From memory you set the boost from a base duty cycle not an actual desired boost pressure so there is probably no brains behind it anyway.

You could try setting the gain to a higher value but it probably wont work anyway. If it is possible which I dont think it is you could check the duty cycle on the valve to see if its attempting to control the boost. As has allready been said it may be a mechanical restriction.

Edited April 23, 2007 by rob82

[Jsikalias]

well i do have a full zorst and an aftermarket intercooler so it must be the wastegate ill have to try changing it.... hopfuli it fixers the prob

[Jsikalias]

has anyone had this problem before and to also add it hold boost at 10psi well, its only when i boost it to 15 it starts to drop at high rpm

[Nismo_God]

turbo running out of puff? what turbo u using?

[skylinecouple]

I had a similar problem and discovered the wastegate arm was hitting the bracket that holds the heat cover because the new dump had a thinner flange.This prevented the wastegate from opening fully and capping boost to 15psi.Anthing over and boost would spike all over the place.However,the duty cycle could be lowered then turn up gain til it spikes then back off a little.

[InterCooL]

what wastegate actuator are you using? a new gcg one or your old standard one? if its your old one, it may be getting a bit long in its years

[Gazee]

couldn't they troubleshoot when your car was on the dyno?

[7yphon]

Have you tried disconecting the Controler to see if it still spikes? because if it was exhaust it should spike up and hold unless your turbo is running out of steam like it was said.

[666DAN]

I'd say wastegate actuator, my one does the same thing (R34 also) with a similar setup...it was diagnosed last time it was on the dyno.

[cheez]

its the gizzmo boost controller,

they are known to spike. i have 2 mates that have had em in their cars and the cun*ts spiked like crazy.

my suggection, get rid of the gizzmo and buy and apexi or similar

[Jsikalias]

yeh the tuner said it could be my wastegate BUT i found the problem, because i have an aftermarket intercooler the new piping didnt give me a nipple for the powersteering vacum so i T pieced it off the boost controller vacum so iv removed the T piece and now it doesnt drop boost it holds 14-15 nice feels faster as well

[Jsikalias]

now i need to find a nipple so i can weld it on the piping any suggestions in melbourne ?

[cheez]

go to like super cheap or repco and buy an air compressor fitting. they thread and can easily be drilled and screwed into the cooler pipe. plus add some sealant around it and ur done.

should look like this hen done

[Jsikalias]

thanks for the help

[cheez]

no probs