Bigger Waste gate for BPU so the turbos can cope with higher boost??

[Guest FKADizzmystar]

Quote from the "HOW TO:BPU" guide;

 

"There is a down side to this. With both cats removed the turbos will in fact over speed far past their safe limit and reach over 1.6bar (23.2psi). This is due to the small size of the jspec wastegate which cannot cope with the increase in exhaust gasses.

At these pressures the ceramic blades in the turbo can become detached from the shaft and therefore cause catastrophic failure of the turbo."

 

with if you added a bigger waste gate?? would the turbo be able to cope then? and how big would the gate need to be

[Nic]

There is very little material around the wastegate opening, plus they are prone to cracking in this area, opening up the wastegate would only make the area even weaker.

[Scott]

There is very little material around the wastegate opening, plus they are prone to cracking in this area, opening up the wastegate would only make the area even weaker.

 

But, could you add a bigger wastegate instead of opening up the one thats on there?

[Homer]

But, could you add a bigger wastegate instead of opening up the one thats on there?

 

The wastegate is integral to the turbo housing so you cannot "add" one, the only way to make it bigger is to grind it out, but thats not possible as Nic pointed out above.

[Scott]

Ahh yes, forgot it was internal. Same with the MR2 turbo's.

[Jake]

Besides which the small stock turbos are not efficient at high boost levels anyway. So there's very little point in going to a lot of effort to enlarge the wastegate anyway.

[Scott]

Besides which the small stock turbos are not efficient at high boost levels anyway. So there's very little point in going to a lot of effort to enlarge the wastegate anyway.

 

My only reason would be to get rid of the restrictor ring and instead control the boost with a boost gauge.

[bolarbag]

My only reason would be to get rid of the restrictor ring and instead control the boost with a boost gauge.

 

Boost controller? Yeah, if I was staying bpu I'd like to have that element of control, but it goes hand in hand with the J-specs, you may lose slight top end but you would gain low down torque due to the back pressure from having a restrictor ring fitted

[Guest FKADizzmystar]

can you fit a bigger external wastegate? or with the stock TT set up you can only have the internal?

[bolarbag]

Think the problem is, no one has went to that level of modification due to all the fabrication work involved (mating an external wastegate to the stock manifold), why do that when you could just buy the UK twins?

[Guest FKADizzmystar]

how much are new UK twins? and then the fitment price? compared to an external waste gate setup? or could you rebuild the J-spec turbos with steel blades?

[Jake]

could you rebuild the J-spec turbos with steel blades?

You could, but why would you want to? The ceramics are much nicer turbos.

[Guest FKADizzmystar]

thought you could get more power out of the UK/US turbos and they last longer

[Jake]

A bit more bhp, a bit less torque. Personally, I wouldn't swap fast spooling ceramics for slower spooling UKs just to gain a little more top end power and sacrifice torque. YMMV

[Guest FKADizzmystar]

another quick question, can you install a BCC without any1 other mods beside apexi air intake??

[Jake]

You can but it wouldn't do anything. An air intake wouldn't make an otherwise stock Supra over boost anyway.

[Guest FKADizzmystar]

so you have to put and exhaust of before BCC

[Jake]

Eh?

[bolarbag]

Yes, your car will not have any gains from increasing the boost with a stock exhaust, plus if you could, your exhaust gas temps would go through the roof!

 

The best idea is to do it all at once, thats when you will feel as if you have made a difference to the car, you would have gains of 50bhp plus and loads more torque

 

p.s the apexi intake has better filtration properties than virtually any other aftermarket intake on the market hence why thats advised, if it was me I'd stick with stock or trd, or if you dont really care about your engine and dont mind replacing it every so often then fit a hks muffler, or any foam one, drill holes in it too for maximum gains and engine destruction;)

Edited May 14, 2008 by bolarbag (see edit history)

[Guest FKADizzmystar]

how do i get the Boost cut Controller to work? is there an order to BPU. like in the HOW TO BPU. http://www.mkivsupra.net/vbb/showthread.php?t=94705&highlight=exhaust+install

[bolarbag]

Boost cut controller/fuel cut, buy one, wire it in, go with a Greddy, the HKS ones are not recommended, cant remember why,its been so long, I think its the way the HKS one fudges the ecu

 

Or go for a F-Con SZ, GReddy Emanage e.t.c piggy back fuel controller if you have a spare 500quid, safest way to prevent fuel cut

 

order, assuming your car is running as it is meant to be from factory

Intake - if needs must

New O2 - you got to assume its not been replaced, ever

Exhaust and decat's - 2.5inch minimum for J-spec, you can go 3inch plus with UK's

Restrictor ring - if your j-spec

Fuel cut Defender - not hks, do both Restrictor ring and FCD at the same time

 

Fuel pump(if you are j-spec), either 255 Walbro or UK/US spec

IK22/24 Denso sparkplugs...or any colder rated than oem

Edited May 14, 2008 by bolarbag (see edit history)

[Guest FKADizzmystar]

yeah awesome. so cat back or turbo back exhaust system? does a down pipe add that much more power?

[Guest FKADizzmystar]

yeah i have the Greddy Boost limiter Cut controller, got brand new of ebay for 100bucks

[bolarbag]

yeah awesome. so cat back or turbo back exhaust system? does a down pipe add that much more power?

 

turbo back, the cat back does nothing but create noise, if your stock exhaust is in good condition you could add your two decats and have similar performance, without the noise

[Guest FKADizzmystar]

so the perfect set up would be:

 

getting rid of the stock down pipe with the two cats on it and putting a straight through down pipe on then,

getting a high flow cat.

and then the cat back part.

 

all 3" to a 4" cannon

 

??