Steve W Posted July 14, 2002 Share Posted July 14, 2002 WHEN does the 'Boost-Creep' occur on a Jap' TT. ? I know if I remove both cat's AND have a 'performance' exhaust It MAY suffer boost creep (although, from threads it seems that this only occurs sometimes ), BUT, WHEN does it occur ? Is it when you hold high revs for long, or, is it high boost (ie. heavy acceleration ? ? ie. IF you just drive normally or 'reasonable' acceleration, will it still 'creep' or is it only if you drive like a complete WAZZOCK ? ? THEY'RE COMING OUT, BUT, JUST PLANNING AHEAD ! ! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 14, 2002 Share Posted July 14, 2002 Boost creep is caused by the wastegate being unable to flow enough volume of bypass exhaust gas to keep boost within desireable limits. It will ocur at wide open throttle, under hard acceleration. The reason some suffer it and otheres don't is down to the flow of the rst of the exhaust, and to a greater extent, production tolerances in how well the wastegate flows. If you were to use my downpipes I have calculated a rstrictor plate that just tips "creepy" engines back into the safe boost region, but I have only had to do this twice, on about 30 or more J-Spec downpipekits I have sold. Basically don't worry about it, although a pair of 3 inch downpipes and a none stock rear system WILL be MUCH more likely to give dangerous boost. Mine are less than 3 inch for this reason. Quote Link to comment Share on other sites More sharing options...
Steve W Posted July 14, 2002 Author Share Posted July 14, 2002 CHEERS Chris, I was/am going to buy your pipes (remember me from ~3 months ago ? ) I'm STILL getting as many faults rectified by the dealer before I go-for-it, BUT, they're USELESS. [ The only reason it's still with them is that THEY gave a 3 year ALL parts/ALL labour Warranty so I want it all 'right' to start. ] NO, I was more interested in what you just said about WIDE throttle/HARD acceleration.... I'm not that loony a driver, so, if I use your pipes I don't think I should need a restrictor (fingers crossed:devil: ). Steve W. Quote Link to comment Share on other sites More sharing options...
GavinL Posted July 14, 2002 Share Posted July 14, 2002 Originally posted by Steve W CHEERS Chris, NO, I was more interested in what you just said about WIDE throttle/HARD acceleration.... I'm not that loony a driver, so, if I use your pipes I don't think I should need a restrictor (fingers crossed:devil: ). Steve W. You should have the car running correctly regardless of your intended use....IMO When you do get your car back (to my mind you have been very patient, I would have been in a lawyers office weeks ago), will the garage honour the warranty once modifications have been made? Quote Link to comment Share on other sites More sharing options...
Steve W Posted July 14, 2002 Author Share Posted July 14, 2002 Gav', The only REAL mod' I'm gonna' make is the cat'removal, and those will go back on before ANY warranty work. THEY fitted the Mongoose cat'back so they can't poo-poo that. I WILL remove the speed limiter BUT that will NOT affect engine/fuelling only speed ? (and would they SEE it easily ? ) I will obviously want to fit a Gauge of some type - the only time it might get awkward is if I use a Controller - that IS a major alteration (increased boost ? ) AND bit harder to take on/off if anything goes amiss ? The only other mod might be the FCD and I suppose THAT could be construed (?) as a performance enhancer as it allows higher boost ? BUT would they SEE the FCD ? I know what you mean though - ANY excuse to get out of warranty work. WE deal with warranties at our garage and if the car hasn't had an oil&filter change every 6 months they won't fix a broken driveshaft ? ! ? (and the link between the 2 is ? ) Quote Link to comment Share on other sites More sharing options...
GavinL Posted July 14, 2002 Share Posted July 14, 2002 Originally posted by Steve W Gav', The only REAL mod' I'm gonna' make is the cat'removal, and those will go back on before ANY warranty work. THEY fitted the Mongoose cat'back so they can't poo-poo that. I WILL remove the speed limiter BUT that will NOT affect engine/fuelling only speed ? (and would they SEE it easily ? ) I will obviously want to fit a Gauge of some type - the only time it might get awkward is if I use a Controller - that IS a major alteration (increased boost ? ) AND bit harder to take on/off if anything goes amiss ? The only other mod might be the FCD and I suppose THAT could be construed (?) as a performance enhancer as it allows higher boost ? BUT would they SEE the FCD ? I know what you mean though - ANY excuse to get out of warranty work. WE deal with warranties at our garage and if the car hasn't had an oil&filter change every 6 months they won't fix a broken driveshaft ? ! ? (and the link between the 2 is ? ) Chris Wilsons downpipes will hold boost at about 17psi essentially what a boost controller would do under normal circumstances. The downpipes are a significant performance mod in there own right. Quote Link to comment Share on other sites More sharing options...
Steve W Posted July 14, 2002 Author Share Posted July 14, 2002 mmmmm..... yesssss.... s o o n . . . . . . . ..............................( I hope ! ) S. Quote Link to comment Share on other sites More sharing options...
Alex Posted July 14, 2002 Share Posted July 14, 2002 Steve, Me thinks you may have forgotten that the FCD is required to pass 15psi...so that will be required before fitting de-cat pipes or a boost controller. EDIT: The FCD and DSC (TRL SLD (TRL produce the best versions of both these pieces of kit)) fit behind the dashboard, my DSC is behind the hazard light switch on the top left of the dash....no-one will notice unless they drive it at over 112mph!! :o Quote Link to comment Share on other sites More sharing options...
Mark Ayling Posted July 15, 2002 Share Posted July 15, 2002 I currently have only one cat removed - if I remove the other, will I be able to keep boost down using my AVCR, or is it not as simple as that? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 15, 2002 Share Posted July 15, 2002 No, the boost controller can only raise boost. The lowest boost is a function of the fixed spring in the wastegate and backpressure in the exhaust. What size pipe have you got at the moment? Quote Link to comment Share on other sites More sharing options...
Mark Ayling Posted July 15, 2002 Share Posted July 15, 2002 At the moment I've got a Hiper with the second cat removed. What is the advantage of removing the first cat if not changing any elements of the engine/turbos/fuelling? (sorry if thats a dimwit question, I'm still learning!) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 15, 2002 Share Posted July 15, 2002 Originally posted by Mark Ayling At the moment I've got a Hiper with the second cat removed. What is the advantage of removing the first cat if not changing any elements of the engine/turbos/fuelling? (sorry if thats a dimwit question, I'm still learning!) No, what I meant was who made the cat removal pipe, is it a 3 inch diameter, or one of mine? The first cat is the more restrictive, removing that makes the engine run more efficiently, and cooler, and the boost goes higher, faster. So long as the boost doesn't creep TOO high (circa 18 PSI absolute tops) ,the stock fuelling system can cope. Quote Link to comment Share on other sites More sharing options...
Steve W Posted July 15, 2002 Author Share Posted July 15, 2002 Chris... DON'T use words like "HIGHER " & "FASTER ".... I just told you, I haven't got my Soop. YOU'RE JUST TEASING ME ! ! ! Quote Link to comment Share on other sites More sharing options...
Steve Cargill Posted July 15, 2002 Share Posted July 15, 2002 Originally posted by Mark Ayling At the moment I've got a Hiper with the second cat removed. What is the advantage of removing the first cat if not changing any elements of the engine/turbos/fuelling? (sorry if thats a dimwit question, I'm still learning!) Mark, mine used to have just the first moggie, but I managed to scare that away. WHAT A DIFFERENCE. I used to get 13lbs, could hit cut on a very cold day.... I'm currently bouncing off the top of Petes FCD (at 16lbs at the mo) after a couple of seconds WOT. I've still got a stock-ish cat back system as well. Go on, you know you realllllllly want it Quote Link to comment Share on other sites More sharing options...
Mark Ayling Posted July 15, 2002 Share Posted July 15, 2002 Originally posted by Steve Cargill Mark, mine used to have just the first moggie, but I managed to scare that away. WHAT A DIFFERENCE. I used to get 13lbs, could hit cut on a very cold day.... I'm currently bouncing off the top of Petes FCD (at 16lbs at the mo) after a couple of seconds WOT. I've still got a stock-ish cat back system as well. Go on, you know you realllllllly want it LOL er, yes, I do want to, but I don't want to blow my turbos!! With my boost controller I can turn the boost up when I want to scare the shit out of myself, so what difference will removing the first cat make? Quote Link to comment Share on other sites More sharing options...
GavinL Posted July 15, 2002 Share Posted July 15, 2002 Originally posted by Mark Ayling LOL er, yes, I do want to, but I don't want to blow my turbos!! With my boost controller I can turn the boost up when I want to scare the shit out of myself, so what difference will removing the first cat make? Turbo spool up will be quicker. As a wise man once said to me "once you have had both cats out you'll never go back" Quote Link to comment Share on other sites More sharing options...
Mark Ayling Posted July 15, 2002 Share Posted July 15, 2002 Originally posted by GavinL Turbo spool up will be quicker. OK, sounds like a good enough reason to me! Quote Link to comment Share on other sites More sharing options...
GavinL Posted July 15, 2002 Share Posted July 15, 2002 Originally posted by Mark Ayling OK, sounds like a good enough reason to me! Indeed, send Chris Wilson a cheque tonight! Quote Link to comment Share on other sites More sharing options...
Mark Ayling Posted July 15, 2002 Share Posted July 15, 2002 Originally posted by GavinL Indeed, send Chris Wilson a cheque tonight! LOL er, how much is it...? Quote Link to comment Share on other sites More sharing options...
GavinL Posted July 15, 2002 Share Posted July 15, 2002 Originally posted by Mark Ayling LOL er, how much is it...? Don't worry about the details send a blank one! Quote Link to comment Share on other sites More sharing options...
Mark Ayling Posted July 15, 2002 Share Posted July 15, 2002 Originally posted by GavinL Don't worry about the details send a blank one! that's not a bad idea actually - maybe I could send a blank one to Justin as well while I'm at it! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 15, 2002 Share Posted July 15, 2002 Originally posted by Mark Ayling LOL er, yes, I do want to, but I don't want to blow my turbos!! With my boost controller I can turn the boost up when I want to scare the shit out of myself, so what difference will removing the first cat make? The engine will be far less stressed by removing the cats than raising the boost with a controller. It's all down to cylinder and exhaust temps. By making the exhaust less restrictive temps drop, which is incredibly important on turbo engines running more boost than yhe makers intended. Quote Link to comment Share on other sites More sharing options...
Mark Ayling Posted July 15, 2002 Share Posted July 15, 2002 Originally posted by Chris Wilson The engine will be far less stressed by removing the cats than raising the boost with a controller. It's all down to cylinder and exhaust temps. By making the exhaust less restrictive temps drop, which is incredibly important on turbo engines running more boost than yhe makers intended. OK, thanks for the info, I understand now! So how much does your de-cat pipe cost Chris? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted July 15, 2002 Share Posted July 15, 2002 Originally posted by Mark Ayling OK, thanks for the info, I understand now! So how much does your de-cat pipe cost Chris? £150 singly, £280 for a pair. I have stock... :-) Comes with gaskets and bolts. Quote Link to comment Share on other sites More sharing options...
Mark Ayling Posted July 16, 2002 Share Posted July 16, 2002 Originally posted by Chris Wilson £150 singly, £280 for a pair. I have stock... :-) Comes with gaskets and bolts. And presumably they're easy to fit? Is it just a case of removing one section of the exhaust and replacing it, or is there more to it than that? Quote Link to comment Share on other sites More sharing options...
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