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Is it normal ? ? ?


Guest Koleto
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Guest Koleto

Hi all , i just go for a test drive my car for first time since i make the swap from n/a to tt ,and saw that the 1st turbo make a 10 psi and the 2nd 20 psi is this normal lol ?:search:

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10 psi or .7bar is right for the 1st turbo.

 

The 2nd one is way OTT for the stock turbo to handle (if its Jspec), you need to have a restrictor ring installed in the Downpipe or a boost controller plumbed in.

 

As above have you got Cats?

What other mods have you done ?? BPU ??

 

If you dont have the supporting mods when boosting more than .9bar then you will have problems with fueling and combustion chambers being too hot. These need to be looked at otherwise say bye bye to your turbos (As that pressure wont let them last long) and possibly worst case engine (due to detonation - Cylinders too hot)

Edited by ManwithSupra (see edit history)
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Guest Koleto

Not just decats ,it's straight pipe 3 inch from the cat to the back box , 3 inch FMIC and a hks air filter... i haven't change a lot of parst so i thing i have like around 330-340...yeaah i know that 20 psi are a lot for stock but what can i do i just make a test drive i saw on the boost gauge ( but the acceleration was amazing :p )

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Guest Koleto
Read the what to look for when buying a [TT] Supra: it covers this and much more.

 

Stever i have the car before N/A and i drive it ,then i make the swap to TT and this happend i don't need to look the things like i'm gonna buy the car now.. thanks anyway :)

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I'd be worried about how long it's been in this condition, you may end up having to replace some expensive parts if it's been overboosting for long. As was said, you just need to fit a restrictor ring between the decats, and a boost controller to up it ot 1.2bar

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Stever i have the car before N/A and i drive it ,then i make the swap to TT and this happend i don't need to look the things like i'm gonna buy the car now.. thanks anyway :)

It also mentions what boost you should see under turbo 1 and then both turbos! ;)

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Guest Koleto

Hyh...i will see is the problem will gonne hope in saturday ,coz i'm gonna change the gearbox coz i'm with the n/a now and i'm waint for keron to sent me the prop shaft so i can swap the gearbox,the problem is there i think ...the n/a gearbox is holding the clutch i think that's why i don't feel to much boost on 1st turbo on 2nd gear and is staing on 3500 to 4000 for 3-4 sec i think and then BOOM 20 psi no fuel cut nothing...i just try it 2 times and didn't hold too much like 2 to 3 sec and then realese the gas pedal, now may be you gonna think me for stupit coz i'm trying my supe whit this gearbox but this was the only way to get it out from the garage where i make the swap , and i wass asking some ppl and they say is not recommendet but it's possible to drive the car whit this gearbox...hope to get thissss precius prop shaft this weak to make evrything right and then i will try again if the car do the same shit... i will buy boost controler to make the things better for my turbos and engine coz i realy don't want to blow my supe :( :S

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It's a bit difficult to understand what you're saying (or maybe I'm just being thick).

 

Just to clarify, have you converted an NA to a TT? Which gearbox do you have fitted to the car now - I presume it's a w58 5spd.

 

The high boost you are seeing is likely to be caused by lack of exhaust restriction (which keeps boost in acceptable levels). Do you have a 1st decat or 2nd decat? Is a restrictor ring fitted?

 

A boost controller will not help matters, it can only increase boost, it cannot reduce it

 

Also, fuel cut only hits after 3 seconds or so of sustained high boost (normally set at 1.2 bar, but some boost cut controllers remove it altogether). Do you know which one is fitted?

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Guest Koleto

Sorry about my language ppl i'm trying to be clear but it's very very difficult for me ....yes i convertet from N/A to TT , it's not w58 5 spd - it's AUTO , now the car is whit the TT engine and N/A gearbox, it's straight pipe 3 inch from the cat to the back box ...no cats and no res ring.

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no cats and no res ring.

 

No cats and no restrictor ring will result in a massive overboost. My last one hit about 24 psi with a full decat and no restrictor. The engine will det itself to death very, very quickly like this (we're talking 5-10 seconds here)

 

You absolutely need a restrictor ring when decatting. Have a read here: bpu

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