C4 supercharger problem advise needed
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Joined: Jun 2000
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From: Salt Lake City utah
C4 supercharger problem advise needed
I completed a Vortech supercharger install this winter and have been drivivg about 3 weeks . I set it up on a dyno and have not pushed it real hard untill yesterday. I was on the freeway at about 70 and I jumped on it. she went to 85 in a beat then she stumbled as if out of gas or lost spark three quick times in a row(almost a stall) I backed right out. This was at wot, if I bring it in at a constant increase I dont seem to have this problem but I have only been to 130mph. It happened once before when I was at a lower speed an jumped her. Thanks
Team Owner
Joined: Aug 2000
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St. Jude Donor '14
Re: C4 supercharger problem advise needed (Dennis McDougle)
What was your fuel level at ? on all my TT cars and supercharged cars if you don't have at least 1/2 tank of gas, the foreward momentum starves the fuel pump. If that's not the problem, then hook up a fuel pressure gage, and tape it to your windshield and see what the fuel pressure is doing when the hesitation is present. I doubt its electrical.
Drifting
Joined: Dec 2001
Posts: 1,313
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From: providence ut
Re: C4 supercharger problem advise needed (8388)
Dennis sorry I can't help as I'm installing a procharger on my 85, but i'm interested in this post an want to know who did your dyno, I live in logan and am looking for a tuner. thanks
P.S. with your present situation would you recomend them
P.S. with your present situation would you recomend them
Le Mans Master
Joined: Oct 1999
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Re: C4 supercharger problem advise needed (8388)
What was your fuel level at ? on all my TT cars and supercharged cars if you don't have at least 1/2 tank of gas, the foreward momentum starves the fuel pump. If that's not the problem, then hook up a fuel pressure gage, and tape it to your windshield and see what the fuel pressure is doing when the hesitation is present. I doubt its electrical.
I was thinking about having a sump welded in and going woth an external pump. I just dont want to remove the fuel tank and rear bumper.
[Modified by bill mcdonald, 1:59 PM 4/28/2002]
Instructor
Joined: Jun 2001
Posts: 208
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From: Cape Coral FL
Re: C4 supercharger problem advise needed (bill mcdonald)
How about a new fuel filter? Might be starving engine also as said before not enough gas in tank. Maybe net on intank fuel tank might have alot of crap. Hope this helps.
Team Owner
Joined: Aug 2000
Posts: 24,125
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St. Jude Donor '14
Re: C4 supercharger problem advise needed (bill mcdonald)
What was your fuel level at ? on all my TT cars and supercharged cars if you don't have at least 1/2 tank of gas, the foreward momentum starves the fuel pump. If that's not the problem, then hook up a fuel pressure gage, and tape it to your windshield and see what the fuel pressure is doing when the hesitation is present. I doubt its electrical.
8388, do you know of a solution for this? My N/A 90 does this in turns with half a tank. I am looking to supercharge it and need to solve this problem. I was told that some autocross guys put another small tank in the fuel line somewhere, and it solved it, I dont see how though... maybe with another pump after that.
I was thinking about having a sump welded in and going woth an external pump. I just dont want to remove the fuel tank and rear bumper.
[Modified by bill mcdonald, 1:59 PM 4/28/2002]
8388, do you know of a solution for this? My N/A 90 does this in turns with half a tank. I am looking to supercharge it and need to solve this problem. I was told that some autocross guys put another small tank in the fuel line somewhere, and it solved it, I dont see how though... maybe with another pump after that.
I was thinking about having a sump welded in and going woth an external pump. I just dont want to remove the fuel tank and rear bumper.
[Modified by bill mcdonald, 1:59 PM 4/28/2002]
Some cars are more sensitive to fuel starvation than others, and this has to do with how the pump sits inside the tank. I was able to minimize the effect on my SC'd car when installing the bigger Bosh pump by positioning the pickup further back. But still its not safe to run a SC or TT car with less than 1/2 tank, if you plan to run it hard.
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Joined: Apr 1999
Posts: 533
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From: Poinciana Florida
Re: C4 supercharger problem advise needed (8388)
My good deed for the day. Been there, done that. As have many on this forum. The stock pump cant keep up with the T Rex./ Replace the stock unit . I prefer a Bosch pump. Basically a drop in installation. Others prefer another unit. Possibly an hours work. Your probably putting out about 405/410 rwhp. your air fuel ratio is probably 13.8-1. If in the future you go the 383/ 9-1 compression route, dual pumps/ lines should be a consideration.
PS--- Don't believe the fuel pressure gauge on the dyno unless the vehicle is under load.
PS--- Don't believe the fuel pressure gauge on the dyno unless the vehicle is under load.
Drifting
Joined: Jul 2001
Posts: 1,897
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From: La Fontaine Indiana
Re: C4 supercharger problem advise needed (RVY)
I agree with RVY you have a fuel problem. I have two fuel pickup tubes and three fuel pumps on my car but the third pump is on a rpm switch and kicks in automatically at 4000 rpms if below that it is not needed. It takes a lot of fuel to make big power. :seeya
