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Problem with stock twins not spooling up right!!


RB-GTE

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My Supra is mostly stock performance wise other than exhaust and 2 row intercooler + intake.. and HKS EVC4

The 2nd turbo usually wasn't coming online, car would be accelerating but didn't feel the punch from 2nd turbo most of the time.

 

Well anyways I just did the TTC conversion just to see if things would change.

Mostly in 1st and 2nd gear the car feels gutless. Sometimes it will be pulling up to even like 5/6k rpm and I don't feel the punch from the turbo's at all.

 

Another thing is that in TTC the car should be constantly loud since the valve is open yes?

well it is on/off. Sometimes it is LOUD, other times it is quieter like sequential.

 

I am thinking the valve is not opening up all the time? IF SO, what is the cause of this? and how could I fix the issue

 

 

Here is somethings that have been checked so far:

 

pressure tank is fine

VSV is fine

boost leak test done, no IC leak or vaccum line leak...

disconnecting boost controller no improvement

 

 

What is the next to-do ?

checking for blocked cat converter possibley or I was reading about some 2 hoses running above the turbo's where they could have failed on the inside?

 

 

I have owned 2 other TT cars and those drove very smooth and responsive. This Supra from the 4 months I've had it has been very sluggish :( I am ready for BPU just need to figure out this problem first.

Edited by RB-GTE (see edit history)
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Sounds like you have checked the things i would suggest. If it sometimes comes online it must be a leak or faulty vsv as if the turbo was gone it would never work. Double check all the vac hoses again mate. :(

 

Hope you get it sorted. I know these problems can be a nightmare and always end up being something simple.

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They do come online quite often but many times as well they aren't spooling up.

 

Will be doing some more boost leak testing with my mechanic and he will be replacing a bunch of the hoses.

And the VSV has been checked he confirmed it is good. So VSV shouldn't be the issue here.

 

The valve not opening up is another thing I'm trying to figure out as well

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all i can say is read this thread http://www.mkiv.co.uk/vbb/showthread.php?35926-The-sequential-system

and check the vsv at the top back of the block that controls the 2nd turbo

 

I'm not sure if it will be the vsv that controls the second Turbo only because sounds like you are having trouble even in TTC mode. So replacing that would be expensive and might not solve it. I guess if you have someone local to swap the vsv over and check that can rule out any faulty vsv.

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If you put your foot down and get nothing, then lift off and back on again hard, do you then get boost? I had a problem with my TT, thought all the lines etc were perfect. Turned out to be two little pipes at the back of the engine that led into the perssure tank. Difficult to see on a TT...worth checking!

Edited by TheTurtleshead (see edit history)
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Yeah if I baby the pedal, and get back on I can usually get the boost start coming on. But usually not as fast as it should come on maybe around 4500-5000 range.

It's mostly in 1st and 2nd gear. It seems to always spool fine at around 5000 in 3rd gear and on.

 

Will be doing some more tests and changing vac lines with my mechanic, if I have any success I'll update this thread.

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I'm not sure if it will be the vsv that controls the second Turbo only because sounds like you are having trouble even in TTC mode. So replacing that would be expensive and might not solve it. I guess if you have someone local to swap the vsv over and check that can rule out any faulty vsv.

 

 

okay not the vsv it self but vac's too it and down the back would be where i would start , replace all vac pipes both sides of the block then go from there

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Just got a call from my mechanic

 

I told him before there is this springy kind of noise after I did TTC.

 

I didn't get the part he said exactly, but something to do with a exhaust valve or wastegate which has fallen apart on the inside and the valve is not opening up causing this issue.

He will remove the full cat to get to it, and this most likely should be the issue.

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sounds like the EGBV which would stop the 2nd turbo coming in, its like a turbo waste gate actuator but for the exhuast,

if it was stuck closed it means no 2nd turbo but if its stuck open would mean you would be in TTC all the time.first time i have actually heard of one failing its normally vac pipes and vsv's to it,

see the problem is that you proved it not to be the EGBV by doing the TTC test and you said that it got louder which proved it opened did it not?

i would plumb all the vac pipe back to stock NO BOOST controlers then see how it is.

i have a EGBV if you need one from my jpec TT its the large actuator on the down pipe just after turbos

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sounds like the EGBV which would stop the 2nd turbo coming in, its like a turbo waste gate actuator but for the exhuast,

if it was stuck closed it means no 2nd turbo but if its stuck open would mean you would be in TTC all the time.first time i have actually heard of one failing its normally vac pipes and vsv's to it,

see the problem is that you proved it not to be the EGBV by doing the TTC test and you said that it got louder which proved it opened did it not?

i would plumb all the vac pipe back to stock NO BOOST controlers then see how it is.

i have a EGBV if you need one from my jpec TT its the large actuator on the down pipe just after turbos

 

When I did the TTC conversion, the car wouldn't be much louder than Sequential. When I got on the car quite a bit in 3rd gear and on, after I got down to 2nd or 1st gear it was suddenly much louder. It was on and off, usually it was just as quite as sequential and other times it would be MUCH louder. It seems to me like the valve is remaining shut most of the time but opening sometimes?

 

I guess this is the important part I haven't mentioned. I was getting a little boost around 2500-3000rpm in TTC, after 3000 none at all. Then after 4000 they would spool up (if the turbo's would come online).

Edited by RB-GTE (see edit history)
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i would plumb all the vac pipe back to stock NO BOOST controlers then see how it is.

i have a EGBV if you need one from my jpec TT its the large actuator on the down pipe just after turbos

 

We already did that and it didn't solve the issue ;)

 

I'm not in the UK but my mechanic should locate me a EGBV. If not I'll let you know!

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When I did the TTC conversion, the car wouldn't be much louder than Sequential. When I got on the car quite a bit in 3rd gear and on, after I got down to 2nd or 1st gear it was suddenly much louder. It was on and off, usually it was just as quite as sequential and other times it would be MUCH louder. It seems to me like the valve is remaining shut most of the time but opening sometimes?

 

I guess this is the important part I haven't mentioned. I was getting a little boost around 2500-3000rpm in TTC, after 3000 none at all. Then after 4000 they would spool up (if the turbo's would come online).

 

"the car wouldn't be much louder than Sequential. When I got on the car quite a bit in 3rd gear and on, after I got down to 2nd or 1st gear it was suddenly much louder"

 

this still proves the EGBV to be working mate, and that the vacuum is leaking away closing the EGBV in TTC mode, when its loud its open but because you have a leak its taking longer to open this is the point you pressuring the sequencial system it SHOULD stay open and loud untill left for a long period unless leaking away!!

 

so i take it that when you get between 5,500 and 7,200 in TTC you car goes like normal ?

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oh dear,am having the same problem,only mine occurs more on higher gear and when very cold.just swap the iacv,and problem remain.one second it's working,few second after it's not.really annoying.:search:

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My mechanic knows his Supra's well, and has a 800bhp one himself. Not just some random guy.

 

He is convinced that it is the 'flap for the EGBV that's lose inside the exhaust' causing the issue.

 

I'll know within the next day or so if this is the case.

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Wow ok so it seems like the issue is still there.

We removed the whole cat, and it was melted on the inside (so this was part of the problem). The possible problem regarding the EGBV above was checked and there was no problems there..

 

So I insalled my 1st and 2nd decat pipe (exhaust is straight through also), so I'm running a 3" straight pipe from the turbo.

 

With the extra power it made it a little more obvious about the current problem.

 

In 1st gear the power is usually non evident, usually the turbos will barely spool up.

In 2nd its about 40% of the time turbos are not coming online, it will be going up to 5000-6000 and nothing.

Other times in 2nd it will spool up perfect.

 

This problem is only occuring in 1st and 2nd gear. In 3rd and up it spools perfect right at 4000rpm in TTC mode.

 

I still don't have the fuel pump, HKS FCD, restrictor ring, or wideband installed.

 

 

So I'm not really sure where to check now for what is causing this, after all the stuff that has already been checked...

Edited by RB-GTE (see edit history)
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what boost are you getting ? if you dont have a boost gauge fit one, and do you have a boost controler fitted if so remove it and plub back to stock, from what you are saying another member had something similar with his auto when he put in manual mode it spooled ok,

but it also sounds like you have a intercooler /intake from turbo side pipe off or leaking

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Did you message Mark??

 

Mark from Whifbitz?

not yet! but this problem can vary car to car it could be many things...

 

what boost are you getting ? if you dont have a boost gauge fit one, and do you have a boost controler fitted if so remove it and plub back to stock, from what you are saying another member had something similar with his auto when he put in manual mode it spooled ok,

but it also sounds like you have a intercooler /intake from turbo side pipe off or leaking

 

Well, since I don't have the restrictor ring fitted, the highest I saw on my HKS EVC 4 was 1.33 bar when I stomped the throttle in 3rd gear (the boost controller reads my current boost gauge). Roads are wet and cold so car did nothing but just slide all over the place. Boost is just spiking up too high. This issue is only in 1st and 2nd. In 2nd I will accelerate even up to 5500rpm and turbo's won't come online, I can let my foot off, let it drop down to around 4000 and on the second or 3rd attempt it can spool up in 2nd. Other times it will spool up right away.

 

Honestly, the car is running superb.. and when the turbos spool it pulls like a monster. They can't consistently come online in 1st and 2nd gear.

 

The boost gauge was already removed and everything plugged back to stock, this didn't solve anything. (this test was done before the decat's were done).

The boost gauge was now hooked up during the double decat install.

 

my ARC 2 row intercooler looks pretty old and dirty, I even noticed the piping has surface rust on it in some spots.

My mechanic already did a boost leak test on it he said and it has no leaks. I can perhaps check it closer myself by taking the bumper off.

 

I feel myself like there is just some kind of leak somewhere based on how the car is behaving.

Edited by RB-GTE (see edit history)
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oh dear,am having the same problem,only mine occurs more on higher gear and when very cold.just swap the iacv,and problem remain.one second it's working,few second after it's not.really annoying.:search:

 

I would like to add,that mine is doing when 2nd should come online.from 4000rpm,my rev won't go up.look like am not moving or moving backward.ohh and a loud sound coming from my blitz sus too.so I will,swap egcv,change 2 hoses between firewall and the engine.also change the 2 big one sitting on top of the sequential system.then we shall see.my money is on the EGCV.cross fingers

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