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Registered
Join Date: Sep 1999
Location: Michigan
Posts: 494
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Whats your red line?
Hay all,
I was just wondering what you all have for a red line. Mines stock, so that makes it 5.5 right? Anyone around 7 or 8? |
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Registered
Join Date: Oct 1999
Location: Marietta, GA
Posts: 809
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We run a GT-3 914-4, 2.0L in SCCA racing. We currently use about 7000 RPM as a redline. I want to get to 8500. They just freed up the rules on us so it may be possible.
neil |
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Registered
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please explain, and forgive my ignorance. how are you raising your redline by that much?.. is it using a stock 2.0 stroke? different valve springs?..
TIA, Jeff |
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Administrator
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If I recall correctly, GT-3 requires stock dimensions for bore and stroke.
The answer, in a nutshell, is "TONS of money!" Big springs, very definitely. Everything balanced to within an inch of its life, most certainly. Lightweight reciprocating and rotating parts wherever allowed by the rules. Lots of cam, lots of carbs (as much as allowed by the rules), lots of head-work, and a well-designed exhaust. Without that, there is no point to going over the stock redline, as power has fallen off to the point of absurdity by 6000 RPM. --DD |
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Stay away from my Member
Join Date: Aug 1999
Location: Agoura, CA
Posts: 5,773
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Neil also didn't state how long his GT3 motor is expected to last...it is obviously not a street car built to run 150-200K miles, eh? I know my stock old 2.0 feels pretty suffocated over 5K and there's no point revving a stocker much higher than 5.5K or so as DD points out...
[This message has been edited by campbellcj (edited 05-08-2000).] |
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Registered
Join Date: Dec 1969
Location: chula vista ca usa
Posts: 5,697
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A stock 2.0l d-jet will not be able to breath much over 6k RPM since the throttle body is designed to keep the RPMs below destruct limits. A GT class racer would have to rev to 7k or higher to be able to keep up with the competition, whereas a 914 used for auto-x would want the power and torque to come on full bore at 3k to 4k and you can usually tell the cars that are made this way as they are top time of the day contenders. The very high rev engines are usually called "grenade motors" for good reasons. The 2.4l engine that I just pulled from my 914 lasted nearly five years and was very seldom reved over 6k.
[This message has been edited by john rogers (edited 05-08-2000).] |
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Registered
Join Date: Oct 1999
Location: Marietta, GA
Posts: 809
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All of you are correct. If our engine survives a couple (2) of race weekends we consider it a good motor. We run the Pauter long rods, FAT counter weighted crank, J&E forged pistons of our own design (total weight 440grams and 13:1 compression), a REED cam of our own design, 48mm Webers (just made legal), 48mm intake and 38mm exhaust valves, springs with 130 lbs seat pressure,and large tube header. We are about to go with titanium valves to further reduce the recipricating mass. We are also working on an aluminum flywheel and clutch package. The prototype is complete and ready for testing.
We go to great lenghts to get increased flow for racing purposes, we race against 240sx nissans, toyota celicas with multivalve engines. The stock motor if I recall correctly really stops producing power around 5000 RPM. Unless you enjoy working on motors I wouldn't try much more. This is our hobby and we do enjoy working on these things. Hope this has given some insight to 8000 RPM. neil |
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Registered
Join Date: Sep 1999
Location: Michigan
Posts: 494
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What kind of times do you get in 0-60 or 1/4 mile on that 2.4l?
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