Robster
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| posted on 10/1/11 at 05:42 PM |
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Hesitation exiting right hand corners
Hi all,
I'm sure most are aware of the problem as it's been discussed before - on the throttle exiting sharp right hand corners I'm getting
a moments hesitation before the engine picks up properly.
I used to have the issue when I started out in the Locost series a couple of years back, and the recommended solution was to fit a fuel pressure
regulator to reduce the fuel pressure to the carb. I did and all seemed well until the final race last year at Oulton - exiting the right hand part
of Brittens the hesitation/stuttering was back, every lap, no matter how I tried to alter my line through the chicane, which of course meant I was
slow all the way down the following straight to Knickerbrook. V.V. frustrating!
I (think) I've seen mentioned somewhere (can't find where tho) that altering the float height in the carb may help?
I'm running the usual Weber 32 DGV carb that most in Locost run - will tweaking the float heights help? Which way should I go - increase the
lower setting (which I think will increase the amount of fuel in the carb) or reduce it? Any ideas how much?
Any ideas appreicated - trying to solve an old problem that I thought was history is driving me mad!
Cheers, Rob.
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snapper
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| posted on 10/1/11 at 05:48 PM |
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Have you got a baffled tank or a swirl pot?
If not could be fuel moving away from the pickup in the tank
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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r1_pete
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| posted on 10/1/11 at 05:55 PM |
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As above it could be tank starvation.
Regarding float, it depends on the orientation of the float relative to the chokes.
If its to the right it will tend to overfuel on right handers, if its to the left it will under fuel.
Front or back it can just be the centrefugal force of cornering preventing fuel getting to the relavent jet, slightly raising the float level may
help.
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Robster
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| posted on 11/1/11 at 03:48 PM |
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Thx both for the replies. Yes the tank is baffled, has a swirl pot & the pickup is on the extreme left of the tank so going through right handers
there's no risk of fuel starvation due to tank pickup.
Orientation - the floats are in front of the chokes. So if it is centrifugal force causing the issue, surely it would also happen exiting left hand
corners???
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samuelgill
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| posted on 12/1/11 at 01:51 PM |
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Hi,
32 DGV's don't need much pressure at all. I set the float levels iaw the book and just kept backing off the pressure till the issue went
away
Sam Gill
[Edited on 12/1/11 by samuelgill]
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Robster
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| posted on 17/1/11 at 12:54 PM |
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Thx Sam, I'll try reducing the pressure further then, easier than fiddling with the floats 
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procomp
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| posted on 18/1/11 at 04:49 PM |
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Hi
This problem is present on more than a few of the cars that race in the championship. The basic settings such as 3-4 PSI at the carb and a float
height set at 38mm - 41mm depending on the angle of the manifold on your manifold and angle of engine in the car will see the very basics set. From
there it gets complex due to the different carbs and combination of power valves fitted if any and pump jet and regular jetting. Whats required
usually to get the best results is a test session whilst running a lambda gauge and data logger to establish whether your chasing a richness or
weakness problem. ( service we offer ) from there you know where to go looking for the problem.
Cheers Matt
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