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Help , cant feel 'hit' from 2nd turbo


dude

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Guys you prob. know im not sure of the performance of my J-Spec , but after driving a uk car tonight i noticed that on the uk the 2nd turbo comes in with a real wallop , mine seems to merge in slowly but i am hitting 1bar , any ideas , both cars de-catted .

John:flame Dev

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From all accounts, it's one of the UK/J-spec differences. A J-spec is making more torque and power than a UK before no.2, but less after, so the difference is greater on a UK than a J. Not to mention that the UK blowers are a bit laggier with the steel internals, which probably doesn't help the smoothness of the transition.

 

Does that make sense?

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The power delivery on the j-specs is so smooth compared to a UK spec you will think its slower, its only once you get it at Santa Pod or somewhere similar that you can actually see how fast it is.

 

Next Pod Bunfight is April 6th....get along there and see how it compares to other cars.

 

JB

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Guys,

 

I've got a stock UK TT (6spd) and the second turbo does not come on with a kick - it just eases in.

 

The turbo is definitely working (I think - I can hear it start to whistle at 3500-4000 rpm) - do you think I have a problem here? If it helps to give you an idea performace wise - a subaru STI has the edge over me until about 80MPH.

 

My intercooler is definitley knackered (8 year old stock Toyota item - very crumbly!), and the car is noticably faster when colder. Do you think this could have something to do with it?

 

Unfortunately I've got no way of reading my boost pressure. Would a low boost pressure problem be identified during servicing? (OK, can they tell anything during servicing!?!).

 

Any ideas?

 

Cheers,

 

Jeremy

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I agree with Pete, you probably wont feel the second turbo come on line. Once you modify the car its a totally different matter. Most supras that have been written off have lost the backend when the second turbo kicked on, and most supra drivers will probably anticipate the second turbo kick as it will break traction in most conditions. The higher the overall boost the bigger that kick should be. I run 1.2bar max (1.3 spike) and it really does kick on the UK spec, on the import I ran up to 1.4bar and the kick was there but not quite the same way.

 

JB

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thing is he has modded it. he has my old downpipe i bought off paul w with that on i was hitting 1.5bar and it was rapid. john has full de-cat and a big fmic and now cam gears. dont know if he has a cat back exhaust or not.

my biggest kick for money has been downpipes.

 

john do you have a stock exhaust?

 

you should be hitting 1.2 bar + i would think. the jap spec dont need a boost controller like uk specs. so you should be getting power.

have you hit fuel cut ?

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Mark and pete

the car has full de-cat , cat back exhaust,FMIC,Mines ECU,HKS inlet,HKS plugs and a blitz BOV , it seems to be making a lot of hissing noise when i drive it (the uk one has a HKS induction kit but no BOV and is nowhere near as noisey)

HELP

John:flame Dev

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Dude

 

Did you remove the stock BOV?

 

I ask because the pipes (3/4'') can get very hard and the stock clamps don't do a good job of sealing .

Just replaced mine due to this...

 

Incidentally , my j'spec with full de-cat and Dual Drager doesn't boost much more than stock either.

I suggest the bleeder 'T' mod as shown on mkiv .com as a quick test to check the 2nd turbo is boosting. Be gentle to avoid huge spikes to 1.5 bar ...... keep an eye on the boost gauge (which will be hard the first time it hits 1.2-3 bar)

 

I wouldn't recommend the mod for prolonged use tho'.......

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Originally posted by dudersvr

Matt

there are quite a few of the vacum hoses i dont like the look of so im changing them to silicone , hopefully this will sort out the prob. if there is one .

John:flame Dev

 

Hmm, the sort of silicone you are probably thinking of using is more likely to split or blow off than quality "rubber" hose. It won't have any fabric liner in it, and as such a tiny nick in the peripherary of the pipes cut end will start a longitudinal split off.

I personally would say decent black rubber hose is best, something like gates hose. Could be a BOV problem?

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Thanks chris, i agree about the hose thing but im trying to spruce up my engine bay as a bit of a showpiece type thing so it really has to be silicone , the car was front end damaged when i bought it (not mega hard) and has prob. sat around for at least 6 months , when i first took it for a shakedown run it was very rapid and hard to keep in a straight line on cold tyres , but a while later it just felt sort of fast , it seems to be making too many wooshing noises so it could be the standard BOV is f***ed , i also noticed that when i removed all the turbo outlet pipes the jubilee clips were only finger tight but there were no obvious signs of blow by to get it over .8 bar you really have to cane it , the turbos appear to have no play in the compressor wheels and it does not smoke , the car has been VERY well looked after with full Toyota history since 1998 (allthough they changed the cam belt but not the idler wheel which is a bit naf so im changing them both again even though the belt is 4000 km's old ) when it goes back together im going to remove the standard BOV so we'll see if this improves things .

John:flame Dev

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im going to remove the standard BOV so we'll see if this improves things

 

I would.

I've seen quite a few Supras now that have blown stock BOV's, including my own. The excessive boost just kills them.

 

As I had a HKS BOV already I decided to just take it off and block up the pipes. Been like a rocket ever since.

 

Pete

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