Turbo lag...reduction
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I am interested in doing the sequential twin turbos. I want keep stock turbo for bottem end and throw on something huge for massive top end. How would I go about doing something like that. Where can I get a manifold for that setup? And how much would it cost me?
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I am not sure what the plumbing on a seq. turbo setup is. But I would not keep the stock one if I was going seq. because the stock one is a good mid power turbo. I would do something with fairly low end(like spool at around 1500 or so) and then do a bigger one that spools at like 4k. That should give you a little better power through the whole range. If you get some compressor maps though you would be able to get so that once the small turbo was out of its eff range the next turbo would almost be getting there. Just my thoughts, sorry I couldn't help you on the plumbing and hardware issues. I am not really sure how you hook up a seq turbo.
Stephen
Stephen
natedizzal,
You DO know that sequential twin turbos are INCREDIBLY hard setups to do, as are supercharger/turbo setups.
If you have to ask, then you do not have the mechanical engineering skills to design that kind of system!
I mean seeing as how the STi's came STOCK with VF30s, they can't be that bad.
You DO know that sequential twin turbos are INCREDIBLY hard setups to do, as are supercharger/turbo setups.
If you have to ask, then you do not have the mechanical engineering skills to design that kind of system!
I mean seeing as how the STi's came STOCK with VF30s, they can't be that bad.
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Originally posted by natedizzel
I am interested in doing the sequential twin turbos. I want keep stock turbo for bottem end and throw on something huge for massive top end. How would I go about doing something like that. Where can I get a manifold for that setup? And how much would it cost me?
I am interested in doing the sequential twin turbos. I want keep stock turbo for bottem end and throw on something huge for massive top end. How would I go about doing something like that. Where can I get a manifold for that setup? And how much would it cost me?
OK....I guess if you threw enough $$$ at it you MIGHT pull it off....
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Originally posted by XstephenX
You could also go with a sequential turbo set up. With a small turbo for the low end and a bigger turbo for the high end. Granted sequential turbos are fairly tough to plumb as I understand it, but they would really give you the best of both worlds. Also with the smaller turbo you would really minimize the lag you are getting.
Stephen
You could also go with a sequential turbo set up. With a small turbo for the low end and a bigger turbo for the high end. Granted sequential turbos are fairly tough to plumb as I understand it, but they would really give you the best of both worlds. Also with the smaller turbo you would really minimize the lag you are getting.
Stephen
Also who would do soemthing like this i havent heard of a small turbo enough for us to do this kind of thing.
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Most people her know what their talking about. Uppipe + downpipe will reduce the lag. But don't forget the Exhaust itself. It also plays a factor in reducing lag. Finally, selection of pipe diameter is also importaint. With the standard TD04, 2.5" pipeing will help, however 3.0" will actually increase your lag. I am speaking from personal exerience here. Becuase I am gearing the car up for VF34, and expecting the need for 3.0" pipeing. So I when ahead with the the 3.0" pipe. And as expect I noticed the increase lag and low torque at low end. Until I replaced the stock turbo. Hope this helps.
Originally posted by shadowsonic
Pretty much a Audi S4 setup than, could our cars handle the bi-turbo setup?
Also who would do soemthing like this i havent heard of a small turbo enough for us to do this kind of thing.
Pretty much a Audi S4 setup than, could our cars handle the bi-turbo setup?
Also who would do soemthing like this i havent heard of a small turbo enough for us to do this kind of thing.
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I was researching because i was going to buy a S4 before the wrx, and its a bi-turbo.
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Car Info: '02 WRX + '15 WRX
Someone in my car club tricked the Subaru staff into replacing his engine for free after using nitrous in a stock WRX. He just took it out, towed the car to the dealership, and said "I don't know WTF happened!".
Don't know if the newer WRX's will take it, but I know someone who twin-turbo'd a 22B, so it might.
Don't know if the newer WRX's will take it, but I know someone who twin-turbo'd a 22B, so it might.
Last edited by Brfatal; Oct 20, 2003 at 10:00 AM.
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It's going to be pretty hard to twin turbo a Ej20. Not enough exhaust to spool them both. Usually twins are done to atleast V6s, for example the 3000GT. From my personal Experience, the VF series are pretty good at eliminating the lag. I have a VF-35 turbo, read somewhere that this used to be the stock STi turbo in the earlier years, and it starts spooling around 2200-2400 which I think its awesome compared to the stock turbo IMHO.
however 3.0" will actually increase your lag
is this true? a shop here in hawaii is offering me a 4" uppipe for $375 and i was gonna get it. my car is all stock and i just want to get something to give it an extra kick. before being offered the 4" pipe, i was gonna get the helix 3" up/down pipe with hks carbonfiber exaust. does getting a big pipe increase your lag?
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Exhaust with turbo charged cars are strange. I'm not sure how corky the Subaru is, I'm going to just start playing with the exhaust now. I do know that you have to have a certain degree of back pressure in order to avoid turbo lag, and that by simply reducing restriction you increase lag but gain upper range performance. The key to reducing lag is to increase the velocity of that column of exhaust gas that's driving the turbine, and supposedly ( I say that because I never sat down and worked the aerodynamics of it ) lack of back pressure can actually slow that column. Also, shorter the intake the better. Whats easier to suck in through, a hose or a straw? With a shorter intake you dont create as large a vacuum in piping and therefor will increase spool up time if anything. Notice on the full drag cars they have the compressor wheel facing straight air.
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Sounds like you're confusing the up and downpipes. first off, there's no such thing as a 4" uppipe. A bigger uppipe would theoretically increase lag, as you want velocity to be at it's highest going into the turbo. Anything after the turbo is the opposite though. get the biggest DP that your ears/wallet can live with, you'll build boost faster and increase top end. turbos don't need/like backpressure. Anyone who's done a 3" DP and noticed "lag" is confusing off-boost power (a 2 liter, low compression engine pulling a 3300+ lb car with tall-*** gearing is gonna feel sluggish until boost comes on regardless!). with bigger exhaust, the car will probably "feel" slower until the turbo starts building boost - which will happen sooner... kind of a trade-off.