not even factory boost?

[firin Supra]

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Hi people woundering if anybody can help got a uk supra and its basically its running bpu mods and the thing is ever since i have had the car its never even boosting to factory spec and i can't understand why. I checked the pipes theres no leak but there is one thing when u put the car in ttc mode it boost to 0.8+ sumtimes not under but when its running in twin mode it hits 0.56 drops to 0.43, second turbo comes in and it goes to 0.68. When the boost controller is on and set to 1.2 bar i only get a 1 bar sumtimes 1.1 or not even that 0.9:taped. What could be the problem Its really pissing me off :taped: coz i also own a mark ll aristo and thats running standard and when the second turbo comes online it really takes off:D and the power is so smooth. Can someone please help thanks.

[marc_p]

LOL at the fact you got more help in the ICE section :d

[firin Supra]

c mon sum1 must be able to help or no wot the problem is?

[heckler]

remove the boost controller to eliminate that from the equation... see how that goes

[prosty]

Are you still using cats or just a straight pipe,

Problems can be: misfitted boostcontroller , or just misadjusted boostcontroller, vaccum leak, pressure hose leak, if you're using cats / cat, it could be clogged, broken turbo(s), clogged exhaust, cracked exhaust manifold

Hope this helps a bit

[firin Supra]

i have a full de cat pipe on there and there is no leak in the vacume pipies or intercooler as i have checked but why is it that when you put the car in ttc mode it works fine again?. I really want to solve this problem but the thing with the boost controller is that it was already on the car when i got it but i cant see that being the problem because it will boost fine that 1 time and then put the foot down again and it dusn't produce enough boost so im really confused.

[heckler]

that sounds like VSV problem, or pressure tank - same happend with mine, so I bypassed the presure tank.

[robin]

I found my car was a little low on boost, about 0.61 on turbo 1 and 0.65 on turbo 2.

After I replaced my old original cats (167k miles) with a nice shiney new one the boost rasied to 0.74 and 0.82. Still on the standard exhaust and everything.

Edit: just saw you posted about having no cats... ignore me.

[firin Supra]

the pressure tank works because when you take of one of the vacume hoses on the top of the engine you can here the vacume release, where is the vsv?

[heckler]

the pressure tank works because when you take of one of the vacume hoses on the top of the engine you can here the vacume release, where is the vsv?

I think its the one on top of the engine (under the pipe work). try bypassing the tank anyway to confirm.

[firin Supra]

ive already changed that but if i take that pipe off will the sequential still work its the 1 that looks like a actuator isnt it?

[heckler]

ive already changed that but if i take that pipe off will the sequential still work its the 1 that looks like a actuator isnt it?

no, you need to give the VSV/actuator a direct pressure feed.

[firin Supra]

how do i do that?

[Steviekid]

Which way did you run the TTC mod?

[firin Supra]

by bypassing the vsvs the one under the turbo and and top of the engine and linking a derect feed of the second turbo where ther are two pipes next to each other, i got the no how of hear of 1 of the links but sorry for not mensioning the names of the vsvs coz they confuse me:rolleyes:

[firin Supra]

sum1 must have had the same problem who nows how to solve thisd weres all the machanical gurus gone:search: sum1 must be able to help me owt:Pling:

[firin Supra]

today i swopped the egcv vsv of my aristo and still did not have any look so i checked all the vsv with a 12v supply and they all work fine coz you here a click so could the problem be with the ecu stopping it from boosting properly? Iv also checked the actuators and alll are opening fine dont seem to be sticking and also checked the pipes again for leaks and theres nothing. Iv also checked the diagram on how to fit the hks evc boost controller and thats seems to be fine also so the only other thing i can think of is the ecu telling it to back off but then im not getting any warning lights so dont no what to do:(

[Steviekid]

Was is still not running properly in TTC though? Have you pressure checked the intercooler?

[firin Supra]

when you put it in ttc mode it works fine and boosting properly its when its back to sequential mode it dosn't. I havn't checked the intercooler cos it works fine in the ttc mode so didnt feel the need to thats why im so confused on what it can be. I had the car dynod at thor and thats when pete noticed the problem and put it in ttc mode. He also checked for leakes in the pipes but found nothing it dus have a front mount intercooler on it which i got from jezz at silverstone but cant see that being the problem even pete said they are a good intercooler. I would have it in ttc mode but its too loud and also too much lag but it did produce 398bhp at the wheels at 1.2 bar :d.

[edge]

Make sure on the smaller VSV's you have the hoses on the right way round. THe large vsv on top of the engine is just a one way but the other 2 vsv's (smaller ones) still let air through one way when 12volts is NOT applied and will let air go through the other way when 12volts is applied. Ands pics of hose arrangements on the vsv's?

[firin Supra]

thanks for that reply edge but iv already done that coz i made sure i checked with the aristo and is the same:eyebrows:

[firin Supra]

Today found the problem withb the car it was the vsv the one on top of the engine, it works but the thing with it, it wasnt letting enough air to flow threw so i swopped it with the aristo and all is well boosting to 0.75 didnt quite let it go all the way as there was to much traffic but im really happy with it now and i just wana say thanks for the advise those people who reply'd to the post you now who you are:d