Fuel swirl pot

[e21-Mark]

On my track car I have had problems with the fuel pick-up in certain corners. Am I correct in thinking that all I need to do is fit a swirl pot? Is the thinking behind that, that there is then a mini resevoir that the engine runs on till you are through the corner? Would I be better to run the tanks with more fuel in or should I just remove the OE tanks and fit an alloy boot-mounted replacement?

[drjim]

What setup do you have now - OEM tanks with e30 in tank pump, or e21 external pump?

Swirl pot is basically a smaller tank that stays 100% full - unless you are running out of fuel. You need a pump to feed it, and another to feed the engine from the pot.

If you go for an alloy tank in the boot you'll need to completely seal the rear bulkhead, which is trickier than it should be as you need to seal down the side of the rear arches. I need to do mine.

If you get an alloy tank, my tip is to get a big one. I have 4.75 gallons and the slug seems to use it all up very quickly, not helped by lack of a fuel gauge sender meaning I only know I'm low on gas when the fuel pump gets noisy and I get lack of fuel manifesting itself in the engine not working very well. I'm going to find my original fuel level sender, drill a hole in the tank, cut some foam out and fit the thing. Alternatively I'm going to get a bigger tank with a sender in it.

Jim

[e21-Mark]

OEM tanks with e30 pump Jim.

Mark W made himself a boot mounted tank and a nice job he did too. Ideally, I would like one that sits in the spare wheel well but as I want to keep the car road legal I think it's just far easier if I leave well alone and simply fit a swirl pot with it's own pump instead.

I also want to switch back to Toyo888's as the Yokos just cry enough after a couple of hot laps, I'm guessing the larger tread blocks are getting far hotter and that's why the car was moving about so much more?

I really want to get to a track day with yourself and any other track e21's. Sadly Cadwell is just a bit too far away. Any other days in the pipeline Jim?

[murran]

yeah a swirl pot is designed to be a mini fuel tank that cant suffer fuel starvation.
but you need two fuel pumps, one feeds the swirl pot and returns to the tank, the other pump feeds the engine and the returns to the swirl pot.
and so abit of mucking about changing fuel pipes ect is needed.
tho its a good idea to have the pump to the swirl pot on an ignition live but also switched via a switch on the dash too (so you can turn it off if you want the ignition on while the cars not running for some reason). and then leave the pump to the engine as it was.... engine ecu switched on cranking (if thats how yours works atm?).

depending on the fuel cell (if you get one) you might still suffer the same starvation problems.....

the swirl pot has four pipes to it. the one lowest in the pot feeds the engine, the third one up is the return from the engine. the second one up feeds the swirl pot, and the top one is the return to the tank...... i think, im sure someone more familiar with these things will be along soon!

what fuel pump set up is the track car running? on mine it doesnt have any fuel starvation while drifting, even with the fuel light on.... until your minutes away from running out entirley that is.

[murran]

ah took me a while to write that^^ i made a coffee in the middle of writing it too.

wierd, ive got just the o/s tank with an e30 in tank pump and dont suffer starvation problems
on yours hmmm might be because the fuel is transfering to the n/s tank on long right hand corners?
i wonder if you could fit some sort restricter valve in the cross over pipe inbetween the two tanks??

[drjim]

Get a swirl pot and another pump, use the existing pump as feed pump. Fit the pot and second pump inside a metal box in the boot, hoses coming up through the floor and suitably grommeted. OEM tanks have good capacity to do a proper session on track (or drive there/back), so if you want to keep it road legal extra box in boot is the way forward.

[e21-Mark]

I think I was pretty low on fuel as after the last session the reserve light was on. I'm going to go for the swirl pot and retain the OE tanks. It makes sense to keep them as they've just been refurb'd anyway.

I would like to get some slicks for sprint events as I'm in a modified class anyway. I know 13's are easy enough to get but unsure about 15's? Are all slicks pretty much the same at clubman level? The guy in the Westfield XTR thingy I was chatting too, used Formula Ford slicks iirc.

A swap to rear discs is in the pipeline although the brakes have been excellent so I'm in no desperate rush to lose the rear drums.

[drjim]

13" slicks cheap as chips ebay or sticky slicks http://homepage.ntlworld.com/trrmotorsp ... ytyres.htm 13" wheels go over drums, what are your front brakes?

15" slicks - much harder to find and much more expensive.

Difference in contact patch minimal, grip from 13" slicks good enough to not notice the difference.

[murran]

id go for 13's just because theres a good source of s/h ex-caterham one on ebay. just run in most of them!

as jim said depends on what front brakes your using and if 13" wheels will fit over them?

[e21-Mark]

The fronts are just OE 323 brakes with EBC red stuff. They've been great so far although I do have a set of Wilwoods to go on eventually.

I'll go for 13'' slicks as I have an old set of Minilites that should do the job. Mind you, I'd quite like some Mahle to go for the authentic County look.

I've been offered some new fibreglass bonnets for £100 each too. If they do turn up I'll let you guys know.

[murran]

http://cgi.ebay.co.uk/Set-4-Dunlop-13-S ... 4aaba8eb57

^^^ the're a little bit wider than the two i bought ages ago, mine were 160 530 13 they fit nice on e21 steels.




tyre sizings different for comp. tyres. "160" is the width, "530" is the overall diameter, "13" size of wheel.

[e21-Mark]

They look just the job.

[Jason_323i]

Mark I have used these guys for some stuff recently seems good value

http://cgi.ebay.co.uk/ALLOY-1-5-LTR-FUE ... 563a01c960


Also I am not sure slicks will be allowed for hill climb sprints in your class, but my mate has about 30 part worn kumho V70 13" part worn semi slicks due a change in tyre supplier for the Scottish XR2 race series

Jason

[e21-Mark]

Cheers mate.

I've just mailed the secretary to ask if I can run slicks or not? Meanwhile, once I get back from Cornwall, I'm going to swap back to 888r's.