randy Posted March 2, 2002 Share Posted March 2, 2002 Hi everyone! Just joined your group. Have a question regarding boost- I would like to know how much boost I can run on a Jap spec without blowing my ceramics? I am currently hitting boost cut on 2nd gear at 6000RPM. I'snt boost cut on jap spec 16psi? With a Profec B turned up full, boost will I hit 20+psi? Quote Link to comment Share on other sites More sharing options...
Syed Shah Posted March 2, 2002 Share Posted March 2, 2002 Fuel cut is nearer 15psi, so you'll need a FCD. Don't drive hard before this as hitting FC is very bad for the car. I think anything more than 18psi is excessive on stock turbos, and if you set the boost controller to max on the j-spec, you'll be over 23psi. Which WILL blow the turbos very quickly :o Quote Link to comment Share on other sites More sharing options...
Alex Posted March 2, 2002 Share Posted March 2, 2002 Randy what's the R2D2 blow off valve like??? I've seen a few pictures and it looks bizarre Syed's right don't exceed 18-20psi there is no point... There have been many discussions on this the search function should help you to find more answers along these lines.. I see you have a custom downpipe, what diameter is it and who made it?? Quote Link to comment Share on other sites More sharing options...
randy Posted March 2, 2002 Author Share Posted March 2, 2002 Sard R2D2 Racing Blow Off Valve is really great looks cool and makes really loud pssssh sound and can be adjusted to how fast you want it to vent. It is very reasonable too only paid 170USD. The custom downpipe was a project I did not want to do. cause I ordered a front pipe from HKS and it replaced only the main cat, they should have mentioned midpipe. Anyways I had to make a front pipe from the turbo manifold to the midpipe flange with O2 sensor to eleminate my precat. Real bummer!! The Jap turbo exit manifold is only a little over 2 1/2" wide so the pipe made was that size till it hit the midpipe which was 3". made it in Stainless steel and was polished too! not necessary but the guy who made it just wanted to impress me with his work. Also the Priest exhaust is 4" with 5" tip. Quote Link to comment Share on other sites More sharing options...
THOR Racing Posted March 4, 2002 Share Posted March 4, 2002 You'll need to obtain a fuel cut controller. Fuel Cut is at 15psi I'd recommend only running 18psi max on stock set up and even then in the summer you must do something to prevent knock, maybe larger intercooler, water injection or octane booster. For fuel cut information see. http://www.trlperformance.com/vfcc.html The TRL VFCC has a secondary threshold at 18psi to prevent you from blowing those stock turbos up. You can of course remove this altogether if required. Make sure you read the NOTES: section on that page. Not many people are aware of what a fuel cut controller (defencer) does. Regards Pete Quote Link to comment Share on other sites More sharing options...
MONKEYmark Posted March 4, 2002 Share Posted March 4, 2002 hi randy how much was the front downpipe to be made.i have a j spec and was wanting to replace front cat too,is it loads louder and is boost out of control.i have got a s/steel de cat pipe and have started getting fuel cut only if i rapidly boot car.if i let it build up slowly and its ok then .i have got a trl fuel cut to fix when its warm got about 6 days of in a couple of days will fit it then,i also need a boost gauge too. can you find out if your mate can get a price of a downpipe to take front cat out.i have stock turbos. i have kept my stock exhaust and cat in case i have any trouble.i would put cat back on for mot. thanks for any info mark Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted March 4, 2002 Share Posted March 4, 2002 Mark - I don't think Randy is in the UK, which may make shipping a custom downpipe a bit expensive. Quote Link to comment Share on other sites More sharing options...
MONKEYmark Posted March 4, 2002 Share Posted March 4, 2002 thanks martin i was just curious is there anywhere that you can buy them. the usa pipes are different and remove 2 cats.i rang up dragon autosports and he said he would make one or modify mine. as anyone got bot cats off and whats the difference like thanks for any info mark Quote Link to comment Share on other sites More sharing options...
randy Posted March 5, 2002 Author Share Posted March 5, 2002 Hi Mark! I was under the impression that de cat means removal of both cats? From what you are saying its just the main cat which is called a midpipe. Well I did remove my main cat at first but was not too happy with the performance gain. Mark removing the pre-cat will make a really big difference as I found with my car. The boost builds so quickly, troque comes on strong as low as 2500/3000RPM it will blow your socks off!! Waiting to boost 19psi~I cant wait to fit my Greddy Profec B, BCC, and 60mm boost gauge/peak hold,warning. Anyway's mate~I live in Bangalore/ India so making a frontpipe which was polished to elimenate the precat cost me 60 pounds including fixing. http://www.geocities.com/randymurthy2002/supra6.jpg (Edited by randy at 10:12 am on Mar. 7, 2002) (Edited by randy at 10:25 am on Mar. 7, 2002) Quote Link to comment Share on other sites More sharing options...
Phil Wall Posted March 24, 2002 Share Posted March 24, 2002 Just fitted my new Greddy boost gauge. It is a very good looking bit of kit. The peak hold and warning are brilliant. I have one cat, the first one, HKS cat replacement pipe and a Hiper. Last night while testing the gauge, with an air temp of 6 degrees, I was hitting 1.12Bar max, which is about 16.5 psi. In the week in between fitting the new exhaust and a TRL VFCC, I hit fuel cut a few times, easy to see why now. Quote Link to comment Share on other sites More sharing options...
randy Posted March 24, 2002 Author Share Posted March 24, 2002 Phill, Man you need to get rid of the pre-cat~ This is where the performance is!!:biggrin: I replaced the main cat at first with the HKS midpipe but the performance gain was not that much, but when I replaced my precat it made a huge difference. The turbo spools really fast at much lower RMP and it builds boost quickly. Made me smile a lot!! Trust me!:biggrin: Quote Link to comment Share on other sites More sharing options...
Phil Wall Posted March 24, 2002 Share Posted March 24, 2002 I know, it is coming off. I have a lovely SS Chris Wilson pre cat replacement pipe sitting in the garage. I just wanted to fit the gauge with warning light so I could ease off if things got out of hand. I just need to check out if I need new nuts and gasket. Quote Link to comment Share on other sites More sharing options...
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