Tarmac Rally Car Advice Needed

[arwel 43 2 Cars]

Hi people. Did Brawdy stages yesterday and although we finished and had a good result there are some issues that have come to light.

 

Firstly is a problem with what appears to be seriously bad fuel surge. Either sharp tight corners or long sweeping corners I get really bad surges if the tank is around half full. Is there anything that can be done to stop this apart from obviously running with a full tank

 

Second problem or more advice needed really. Car has been used for road rallies, for you that arent aware a road rally is a event run from around midnight on a saturday on open public roads where the aim is to visit all controls and pick up all code boards and maintain an average speed of 30mph. Events usually use old farm tracks and farm yards as part of the route to keep speeds down so the routes can be rough at times. As this is the case im using Group N spec struts and forestry springs. Cant remeber what poundage they are but when competing on tarmac stage events the amount of body roll is a bit much for my liking. To eliminate the body roll or reduce it what would the best springs be to use? Full Tarmac ones with a higher poundage rate?

Also the rear seems to be the same, Im thinking my beam has seen better days aswell so shall be looking at rebuilding or replacing it. That also has Grp N struts on the rear, would different torsion bars be the way forward on that and if so what diamiter? Beam is a standard 1.9 gti with above mentioned struts and solid mounts.

 

Cheers

Arwel

[welshpug 1,666]

A swirl pot and second fuel pump will alleviate the fuel surge issues, or a custom fabricated baffled ally tank in place of the original plastic unit.

 

 

If you aren't struggling for grip I would leave the spring rates, you could uprate the rear quite easily though that's not seen as such a good idea down the lanes as it moves the back end around rather more on the uneven bumpy single tracks, uprating the torsion bars would help though.

[jorg 11]

The fuel surge issue is something I have been trying to eliminate since I started my builds, first on the 205, now on the 306. I will be running a swirl pot and second fuel pump under the boot floor just like the 306 high boost supercharged cars do. And as I have about 30 litres of fuel tank baffle foam I will be putting that in the tank too.

 

For the 205 I managed to get hold of an alloy half size tank, which sits in the original tank position but on the drivers side. I was hoping to use the free space under the rear seats on the passenger side to mount a swirl pot and second pump but due to a lack of fabricating skills on my part I abandoned any hopes of getting it sorted. There are solutions but it depends of how much time/money you want to spend. If you click the link below you will find all the past topics on fuel surge that have been discussed on the forum, well worth a read

 

https://www.google.co.uk/search?q=steering+bosses+site%3Ahttp%3A%2F%2Fforum.205gtidrivers.com&hl=en&num=10&lr=&ft=i&cr=&safe=images#hl=en&lr=&sclient=psy-ab&q=fuel+surge+site:http%3A%2F%2Fforum.205gtidrivers.com&oq=fuel+surge+site:http%3A%2F%2Fforum.205gtidrivers.com&gs_l=serp.3...2653.4598.0.5045.10.10.0.0.0.0.63.521.10.10.0...0.0.rSm42LVGfnI&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.,cf.osb&fp=1deb3a27a4d9b1ab&biw=1920&bih=950

[tri_longer 25]

Some of the later fuel tanks were baffled, but it's hit and miss finding one, I have a 91 plate and thought it was bafffled until I had the same issue and had to run a full tank to stop it. I now have a custom tank which cures the problem, the other alternative as suggsted is a lifter pump and swirl pot, but bear in mind where you put it as if it's inside the car then it will need to be boxed in for firewall purposes.

[arwel 43 2 Cars]

Thanks for the replies guys. Looks like the swirl pot idea is the best then.

 

Any recomendations on the torsion bars?

[allanallen 528 2 Cars]

Thanks for the replies guys. Looks like the swirl pot idea is the best then.

 

Any recomendations on the torsion bars?

 

Just for reference, I run 21mm bars/19mm arb and billy grpAs on the rear of my road rally car (180lb/challenge dampers on the front). It's very good on the rough stuff and nicely composed on the road. Considering the standard ride height and soft tyres it corners very flat on Tarmac.

[309jazzpanda 41]

Where did you get your 21mm bars from?

[welshpug 1,666]

i got mine from Anthony

[allanallen 528 2 Cars]

My 21mm bars are PTS ones which Chris penrose now supplies (309pug on here IIRC) but I also run a set of bars supplied by 205turbo/Anthony off here which are also highly recommended.

[309jazzpanda 41]

Are you running the fixed base or coilover on the front of yours Allan?