mac79 Posted February 3, 2015 Share Posted February 3, 2015 Just a quick question i will have the first decat done on friday on my TT. It already has a boost contoller fitted do i need to set low boost to 1.0 as it will boost to that anyway its set at 0.8 atm. Quote Link to comment Share on other sites More sharing options...
Scott Posted February 3, 2015 Share Posted February 3, 2015 Do you have a restrictor ring in place? The second CAT, if it's still in place, might not have enough back pressure to hold 1.0bar. Quote Link to comment Share on other sites More sharing options...
mac79 Posted February 3, 2015 Author Share Posted February 3, 2015 I have got the RR off whifbitz as i dont have a second cat. I have my high boost set to 1.2 ready i was just wondering about the low boost? Quote Link to comment Share on other sites More sharing options...
Scott Posted February 3, 2015 Share Posted February 3, 2015 I have got the RR off whifbitz as i dont have a second cat. I have my high boost set to 1.2 ready i was just wondering about the low boost? Don't worry too much about the boost settings until you know exactly where you stand. Once it's all together turn the boost controller off, or set it really low, and see what it boosts to. Whatever it hits, is your minimum boost from now on. You can pretty much hit any figure between 0.8 and 1.x with a double decat and restrictor ring in. It's not an exact science and relies a lot on your individual engine/exhaust setup. My setup saw 0.9bar of boost with no boost control, and that was with a 1.2bar restrictor ring in. I wasn't happy with that so I gently opened it out until I saw 1.1bar. It's important that you don't have too much of a restriction when boosting to 1.2bar using a boost controller. It generates a lot of heat and increases the EGTs massively. In my opinion 1-1.1bar of boost with no control is the ideal, the extra 0.1-0.2 gotten from the boost controller keeps everything in check and allows for any cold weather spiking. Once you have the kit all setup, lower the boost to 0.5bar and report back with what you get Quote Link to comment Share on other sites More sharing options...
mac79 Posted February 4, 2015 Author Share Posted February 4, 2015 So once it's all set up, run with no boost controller. See what it's getting. I have an original profec b fitted (it came fitted to the car when it came from Japan) So I am not sure how I will take it down to 0.5. Quote Link to comment Share on other sites More sharing options...
Scott Posted February 4, 2015 Share Posted February 4, 2015 Should be fairly easy to google the instruction manual. Most boost controller instructions are online Quote Link to comment Share on other sites More sharing options...
mac79 Posted February 4, 2015 Author Share Posted February 4, 2015 I have some instructions. With the way you set it up, start at nothing then turn it up till you hit the boost you want on your boost gauge. So if it will naturally boost higher than 0.5 it does not have a set max boost option on it (it's that old). Quote Link to comment Share on other sites More sharing options...
Scott Posted February 4, 2015 Share Posted February 4, 2015 Can you not switch it off? Off would be your minimum boost, on would be your maximum boost. Quote Link to comment Share on other sites More sharing options...
mac79 Posted February 4, 2015 Author Share Posted February 4, 2015 I can. That does sound the easiest way to run it. Quote Link to comment Share on other sites More sharing options...
costas1 Posted February 6, 2015 Share Posted February 6, 2015 is it a jspec supra? if yes do not expect too much work from the boost control as they tend to overboost a bit..all comes to what ring you have..if you hit 1.1 with the controler off thats pretty much your minimum..and because you can not go much higher than that (0.1) cause is dangerous for the j specs the controler is pretty much useless..to set it you just start from 10% and keep rising until you get the boost you want..but as i mentioned you will have the boost from the ring at 5% of the controler and max at 10%...as scott said keep it off and enjoy the boost from your exhaust.. Quote Link to comment Share on other sites More sharing options...
mac79 Posted February 6, 2015 Author Share Posted February 6, 2015 It is a Jspec took it out this evening with controller turn off acceleration is better and quicker spool up but still only seeing 0.8 tried a few times and it only just made it over 0.8. Turn on the controller in high boost and it hit 1.2 bar no problem and quick. The RR is a wifbitz one. Does it need opening up a bit? Quote Link to comment Share on other sites More sharing options...
Scott Posted February 6, 2015 Share Posted February 6, 2015 Yeah I would definitely open it up. Do it a little at a time though, it'll surprise you how little it needs changing to impact the boost. It's a PITA but once you've had a few goes at it you will gauge how much to take out to make a difference. Once done, you'll have a very safe and healthy car Quote Link to comment Share on other sites More sharing options...
mac79 Posted February 6, 2015 Author Share Posted February 6, 2015 Thanks for the advice. How much is a good bit to open it up by? Maybe 5ml at time? Quote Link to comment Share on other sites More sharing options...
Scott Posted February 6, 2015 Share Posted February 6, 2015 Thanks for the advice. How much is a good bit to open it up by? Maybe 5ml at time? I would be more likely to try 1mm. If that makes no difference, try 2mm. I wouldn't try much more though tbh. Quote Link to comment Share on other sites More sharing options...
mac79 Posted February 6, 2015 Author Share Posted February 6, 2015 I will give that a go tomorrow. I will let you know how I get on. Quote Link to comment Share on other sites More sharing options...
Nic Posted February 7, 2015 Share Posted February 7, 2015 is it a jspec supra? if yes do not expect too much work from the boost control as they tend to overboost a bit..all comes to what ring you have..if you hit 1.1 with the controler off thats pretty much your minimum..and because you can not go much higher than that (0.1) cause is dangerous for the j specs the controler is pretty much useless..to set it you just start from 10% and keep rising until you get the boost you want..but as i mentioned you will have the boost from the ring at 5% of the controler and max at 10%...as scott said keep it off and enjoy the boost from your exhaust.. Do you really know what you're talking about? Quote Link to comment Share on other sites More sharing options...
costas1 Posted February 7, 2015 Share Posted February 7, 2015 (edited) .what do you mean nic? All i am.saying is as far as boost goes cause the car already is boosting according how open is the restrictor ring and because is a j spec you can not go beyond 1.3 bar well thats about it..yes probably it will boost better with a boost control but thats pretty much it...thats my opinion anw...if you disagree feel free to explain Edited February 7, 2015 by costas1 (see edit history) Quote Link to comment Share on other sites More sharing options...
mac79 Posted February 9, 2015 Author Share Posted February 9, 2015 I ended up taking about 2ml off and it's all good now. Quote Link to comment Share on other sites More sharing options...
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