On slicks and fuel starvation

[abrussich]

Having just switched from the Yoko A048 to a full race slick I have encounetered a problem with what feels like momentary fuel starvation during high speed left hand turns. Had the car out on a track this weekend where the turns are fairly high speed able. When getting on the gas in the turn the car would sputter momentarily, almost as if hitting the rev limiter, and then run normally as the turn straightened out. If I applied the gas gingerly the "miss" would not happen. If throttle was applied more liberally the sputter would occur.

This never happened in any right hand turn.

Because of the higher G's experienced with slicks is it necessary to adjust the fuel pressure in the system and if so, how is the adjustment accomplished.

Any assistance would be greatly appreciated.

Al B.

U.S. 2-11

Edited February 21, 2011 by abrussich

[Bibs]

What fuel tank have you got Al? The bag tank is baffled to avoid this problem.

Is a swirl pot an option?

[Mr.Oz]

Mine did the same thing. My factory fuel tank had the baffles come loose, my dealer installed a up-graded tank

and I have no more problems even running down to less than 1 gallon of fuel. I am running Yoko slicks.

This was warranty. Check with your dealer.

[abrussich]

Currently the car is equipped with the standard non fuel cell tank. Same as what comes on all U.S. spec Elise/Exige variants. Considering the nature of the beast you would have thought Lotus would have installed a proper fuel cell but such is not the case.

Will enquire about the fuel cell offered by Lotus Sport and see how that goes.

Al

[Jack]

I think it's a traction control issue.

You don't need a fuel cell (except for safety concerns). If "TC off " doesn't take care of the issue, follow Dan's advice.

[ads_green]

The problem is

- the standard fuel pump has a relatively small baffled section. The supercharged car can exhaust this very quickly.

- the baffles in the tank are only half height and 211 cornering on slicks can generate enough load to cause overspill

- the standard baffles have been known to come loose.

The 70liter fuel cell supplied by lotus is made (indirectly) by Pro-Alloy.

They make the primary aliminium tank section and ATP add the rubber sections and sell the final product.

Unless you need the bag tank for racing regs, extra range or the extra safety aspect then I would go with a normal pro-alloy replacement tank. The cost of the bag tank is high and needs to be looked after and has a fixed lifespan (5-7 years) before it must be replaced.

The normal ali tank is a like for like tank with an extra 10 litres of fuel capacity. Can be spec'd with or with safety foam which indirectly helps with fuel surge by slowing the movement down.

The main differentiator from stock is that the pro alloy tank apart from being much lighter and bigger is that the baffles are full height. They also have one way valves that allow fuel to move close to the pump but then close under any left turn. There are small "mouse holes" to allow the fuel to stabilise slowly. This buggers up the fuel gauge and you'll need to be aware (both with the ali and bag tank) that the fuel gauge will read high when moving. Takes about 10 minutes to stabilise after a track session.

However they've used this on racing elises pumping out 300-400 bhp and not had any starvation down to 3-4 litres.

To me this is the best option as its a simple diy operation to swap the tank over if you're handy with spanners. Fitting a swirl pot can also be done and there are kits but I don't see the point of the extra complexity for no gain over the pro-alloy tank.

[Scotty C]

Pro alloy tank will solve your problem

http://www.proalloy.co.uk/

if your ordering a tank from pro alloy, dont forget to get theses while your there.

http://www.proalloy.co.uk/cgi-bin/sitewise.pl?act=det&pt=52_921_62_178&p=885&id=proalloy

Say hi from me.

Scotty C

Edited February 23, 2011 by Scotty C