dRuNk-mEdIc Posted March 23, 2005 Share Posted March 23, 2005 That intake manifold is very pretty wow I love it. Homer by any chance why did you change your fuel pump. I heard it lowers performance?? Quote Link to comment Share on other sites More sharing options...
Homer Posted March 23, 2005 Share Posted March 23, 2005 Homer by any chance why did you change your fuel pump. I heard it lowers performance?? Its a JDM car. The JDM pumps are not as strong as the UK/Euro/US spec cars so when you up the boost its wise to upgrade the pump. A single Walbro offers similar flow to a NEW US/UK/Euro spec car and is far more cost effective - a no brainer really when upping the boost on a Jap car. Edited to add: Why would consistent sustained fuel supply degrade the performance? Quote Link to comment Share on other sites More sharing options...
dRuNk-mEdIc Posted March 23, 2005 Share Posted March 23, 2005 Yeah, I forgot this is a UK site with JDM Supra's. It is a no brainer but since im in cali yeah, its kinda different Quote Link to comment Share on other sites More sharing options...
dRuNk-mEdIc Posted March 23, 2005 Share Posted March 23, 2005 This is kinda stupied but do you got emissions in the UK? Quote Link to comment Share on other sites More sharing options...
Homer Posted March 23, 2005 Share Posted March 23, 2005 Thread hyjack in progress!! Medic, yes, we get emission tested but as I understand it the restrictions are FAR less than in the US, particularly Cal. My car pased the UK MOT with a straight though pipe and no Cats Quote Link to comment Share on other sites More sharing options...
Robert Posted March 23, 2005 Share Posted March 23, 2005 Thread hyjack in progress!! Medic, yes, we get emission tested but as I understand it the restrictions are FAR less than in the US, particularly Cal. My car pased the UK MOT with a straight though pipe and no Cats how did it pass with no cats? did you know the guy doing the MOT? Quote Link to comment Share on other sites More sharing options...
Robert Posted March 23, 2005 Share Posted March 23, 2005 forget my last post Quote Link to comment Share on other sites More sharing options...
dRuNk-mEdIc Posted March 23, 2005 Share Posted March 23, 2005 Wow amazing you can't pass with a single turbo with a cat here . Sucks bigtime Quote Link to comment Share on other sites More sharing options...
Ian C Posted March 24, 2005 Share Posted March 24, 2005 Dude, What's important is mass airflow. The mass of air on the atmospheric side and the pressurised side will always be the same, so the MAF meter will always report the correct amount of air entering the engine. I think the temp sensors in hot-wire MAF meters are there for some sort of internal compensation. Aha - but, I just made sure that the MAF based cars also have an intake air temp sensor. Could this be for measuring post-turbo/intercooler air temps and adjusting fuelling to suit? For intercooler degradation, overboosting, etc.? -Ian Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted March 24, 2005 Share Posted March 24, 2005 The Bigger intake is of absolutely no use unless you have Huge power, and then you should be looking at the likes of a Veilside etc. If anything a larger unit may actually lose a bit of low down torque. Those who saw my car run yesterday, did it seem to be struggling?? Now look at the size of a stock VVTi intake. Quote Link to comment Share on other sites More sharing options...
Digsy Posted March 24, 2005 Share Posted March 24, 2005 The Bigger intake is of absolutely no use unless you have Huge power, and then you should be looking at the likes of a Veilside etc. ...and then I guess you might be using a bigger throttle body as well? Quote Link to comment Share on other sites More sharing options...
Guest Usmann A Posted March 24, 2005 Share Posted March 24, 2005 I agree, the stock intake gives the best response to power ratio, it helps by having longer intake runners, these help the motor make more torque, and response as air velocity is increaced on low cylinder filling(cruising) Whereas, the likes of aftermarket manifolds(Veilside,etc) all have short stubby runners which hurt low down response but at big HP levels its all about getting air in and out as fast as possible. Intake mani. tuning design is down to pulse tuning thoery, making sure the pusle from the manifold return hits the intake valve at the correct time for efficent power, But again, if you want BIg HP, in and out is what its all about. This is IMO btw, and from looking into early jaguars/fords intake tuning thoery. Re, the air temp sensor, if you are talking about the one built inthe MAF, then I would have thought that it was in direct relation to the mass of dry air vs temperature factor table, built into the stock ecus alithogram. I have seen a supra with a MaF based on the outlet of the intercooler too! I have a few pages of MAF( non-vvti) based alithograms, and boy o boy the stocker is dapper unit. Judging from those alithograms and from what tel says, those Vvtis are no joke fellas!!! Quote Link to comment Share on other sites More sharing options...
Digsy Posted March 24, 2005 Share Posted March 24, 2005 I agree, the stock intake gives the best response to power ratio, it helps by having longer intake runners, these help the motor make more torque, and response as air velocity is increaced on low cylinder filling(cruising) Whereas, the likes of aftermarket manifolds(Veilside,etc) all have short stubby runners which hurt low down response but at big HP levels its all about getting air in and out as fast as possible. Intake mani. tuning design is down to pulse tuning thoery, making sure the pusle from the manifold return hits the intake valve at the correct time for efficent power, But again, if you want BIg HP, in and out is what its all about. Guys, its a forced induction engine. Runner tuning doesn't matter because the engine is having the air compressed and rammed down its throat at a bazzillion bar. Off boost and on NA's, yeah. But on boost it doesn't matter a fcuk. Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted March 24, 2005 Share Posted March 24, 2005 ...and then I guess you might be using a bigger throttle body as well? Absolutely, 100mm Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted March 24, 2005 Share Posted March 24, 2005 Guys, its a forced induction engine. Runner tuning doesn't matter because the engine is having the air compressed and rammed down its throat at a bazzillion bar. Off boost and on NA's, yeah. But on boost it doesn't matter a fcuk. On the pukka ones it's a distribution thang Quote Link to comment Share on other sites More sharing options...
Ian C Posted March 24, 2005 Share Posted March 24, 2005 Guys, its a forced induction engine. Runner tuning doesn't matter because the engine is having the air compressed and rammed down its throat at a bazzillion bar. Off boost and on NA's, yeah. But on boost it doesn't matter a fcuk. I'll just paste that into a tech article shall I? -Ian Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted March 24, 2005 Share Posted March 24, 2005 LOL, @ Chis At some point the TB must become a restriction, as must the manifold, but where. 600-700 bhp++. That was my point the VVTi manifold is fecking tiny, but my car doesnt seem to suffer for it. It think unless you have a really big single the modified stock manifolds are snake oil to a degree. The Purple car made 690 bhp on a stock manifold. Quote Link to comment Share on other sites More sharing options...
Digsy Posted March 24, 2005 Share Posted March 24, 2005 On the pukka ones it's a distribution thang Good point, but that's more plenum volume that runner length, I would have thought? Now that would be a benefit of a larger plenum (but not to the tune of 40 or 50bhp). Quote Link to comment Share on other sites More sharing options...
Guest Terry S Posted March 24, 2005 Share Posted March 24, 2005 I assume they have correct length/design velocity stacks. The VS one looks like it has been given some thought. Obviously the volume helps especially with a 100mm TB. I would be suprised if you saw 50 bhp on an 800+ bhp car, but nothing on a 400 bhp one. Quote Link to comment Share on other sites More sharing options...
Guest Usmann A Posted March 24, 2005 Share Posted March 24, 2005 Guys, its a forced induction engine. Runner tuning doesn't matter because the engine is having the air compressed and rammed down its throat at a bazzillion bar. LOL,.yes I agree(I should have put that comment in the correct context,sorry, I meant it as a kind of universal intake tuning thoery), pulse tuning does not count for much in forced indution engines, but runner diameter and lenght have a influcence the shape of the power curve, diameter can fix a certain RPM for peak HP, while the lenght can tune response, etc. BTW guys. Im not saying go get a intake manifold, as TBH most of us on here will not reach the TB limit, and that toyota spent alot of time tuning the intake for street respone, and has been proven to make big HP too. Quote Link to comment Share on other sites More sharing options...
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