turbo boost

[Elma]

Hi, I amtrying to find a bit of information about manuel boost valves, such as, How much can i boost a stock turbo and at what point of the guage do you take it from. Mine idles at -4 and goes up to +6 when you give it a boot full.
Also how much BHP am i likely to get from a manual boost? Any help greatfully received. Kev

[Martin P]

manual boost valves are not the best way to up the boost as they can cause surge etc,

yours sound s like it running stock psi, the factory gauge is not the most accurate, but its ok, you will be better off saving for a ebc, (electronc boost controller). they you can adjust the boost more controllably, you will hit fuel(boostcut) between 9-11 psi all cars are different, the ct26 runs out of efficenticy at around 14psi so your are not far off that when you hit fuel cut.
EBC example.

http://cgi.ebay.co.uk/JDM-HKS-EVC-4-electronic-boost-controller-S13-S14-RB20_W0QQitemZ180287077300QQcmdZViewItem?hash=item 180287077300&_trkparms=72%3A12%7C39%3A1%7C66%3A2%7C65%3A12%7C24 0%3A1318&_trksid=p3286.c0.m14

http://cgi.ebay.co.uk/JDM-HKS-EVC-3-electronic-boost-controller-S13-S14-RB20_W0QQitemZ180256229562QQcmdZViewItem?hash=item 180256229562&_trkparms=72%3A12%7C39%3A1%7C66%3A2%7C65%3A12%7C24 0%3A1318&_trksid=p3286.c0.m14

As for power, it hard to say, but you will notice a increase, as a word of warning check the turbo for play in the turbine shaft, before upping the boost!

[Elma]

Another job i was going to do was remove the cats, Is this worth while, how long will it take or is it better to buy a decat, (i was told i could just drill them out?)

[supramad77]

I thought it was about 15bhp per 1 psi gained. Something like that. There was a guid that had it all there.
Believe me if you are on stock boost when you get 9/10 psi you will feel the difference.

If i were you though i would get a 3" exhaust and a K&N induction kit on first. That will see you up to 8 psi. Hard pipe and larger intercooler got me to 12.2 psi with my AVC-R boost control switched off. You get the idea.

[Martin P]

De cat down pipe and knock out second one is a cheap fix, and a 3" turbo elbow, would help but they are expensive! stock intercooler is good for 350 plus! so leave that, for now! get a decent air filter as pat said also replace all your boost pipe clamps and check condition of pipes to eliminate any boost leaks

[Elma]

De cat down pipe and knock out second one is a cheap fix, and a 3" turbo elbow, would help but they are expensive! stock intercooler is good for 350 plus! so leave that, for now! get a decent air filter as pat said also replace all your boost pipe clamps and check condition of pipes to eliminate any boost leaks

I have already got a k&n filter but it is only the elliment not a induction kit is that good enough? Where would i find a 3" elbow?

[Elma]

I have already got a k&n filter but it is only the elliment not a induction kit is that good enough? Where would i find a 3" elbow?

Is it just a case of knocking the cat out or is there a bit more to it?

[Martin P]

Is it just a case of knocking the cat out or is there a bit more to it?

yes knock the centre out wear a dust mask! or buy a decat pipe and sell cat to scrappy! and one from downpipe! worth a bit in scrap!

[Martin P]

I have already got a k&n filter but it is only the elliment not a induction kit is that good enough? Where would i find a 3" elbow?

element is ok, doesn't suck in warmer air from engine bay and is quieter.
Keep an eye on www.supramania.com (http://www.supramania.com) for second hand.

new
www.suprasport.com (http://www.suprasport.com) usa or www.suprasport.nl (http://www.suprasport.nl) in europe. they can be got for as little as $75 shipped:yes: or American ebay:) just search for supra 86-92 parts.

[Elma]

De cat down pipe and knock out second one is a cheap fix, and a 3" turbo elbow, would help but they are expensive! stock intercooler is good for 350 plus! so leave that, for now! get a decent air filter as pat said also replace all your boost pipe clamps and check condition of pipes to eliminate any boost leaks

If i knock the cat out will it give me a noticeable gain or is it very small?
Sorry about all the questions but im not a supra expert

[Martin P]

If i knock the cat out will it give me a noticeable gain or is it very small?
Sorry about all the questions but im not a supra expert

small gain but it helps get ex gases out quicker, every bit helps on these, more so as cat is at least 15 yrs old! and most likely partly blocked up.

[supramad77]

Keep your eyes out for second hand parts on here, supramainia and ebay. Nearly all my parts were second hand. TBH i would just ditch the stock exhaust it is very restrictive.
Like i said i gained more than 2 psi which is 30bhp by replacing it all including the elbow.
I know most say the intercooler is good for 350/400 bhp but i had a very big gain by replacing mine.