Clive's 400 BHP Super GT RX-8 Race Car

[boosted]

Quite expensive!  You dont need doors or a roof clive!.....just a coat! And a hot car to dive into after!

[Grant Monkhouse]

Many thanks for the links guys but, one its a lot of money, next there is no weight mentioned, next my doors are now very light after a huge amount of attacking with a disc cutter leaving just the outer skins.

I would also have had a problem had I wanted to buy, parting with my hard earned cash toward the man who is selling them, but thank you anyway.

Hahahaha rather burn your money than give it to him hey Clive;)

[clive]

Next update ----as you will see below I have spent the weekend  making up a revised fuel system :cool.

I have reverted back to a stock fuel pot assembly with a Walbro in place of the stock pump then powered up with a full 12volts powering both pumps via a swirl pot with the exterior assembly sitting on the small rubber mounts below.


I know the RX-8 fuel pump has a variable speed by different voltage but I was still  staggered to find  just 4.8 volts, whilst this is not a problem for even a modded RX-8 this was obviously what was causing many issues at Brands.

Next up from what I found at Brands was those small F1 style door mirrors that needed adjusting every time I set out of the pits.

As you will see, now on stock mirrors.

Lastly I thought I would share how to cut your braided hose easily without special tools.

Even with a thin cutting disc you can still have it frey and you risk metal dust going up the inside.

By using insulating tape bound tight then tin snips, lay them on the ground and hit with a good size hammer and you will have a clean cut in one hit and braided that\'s not a mess on the ends;)

[Martin Price]

Your fuel system is very similar to ours now, our whole set-up even sits on identical rubber bobbins to the ones your using.
How are you planning on boxing it all in Clive?

[clive]

Hi Martin,

Funnily enough I was just coming back on to say that I still need to box it in yet :Giggle

I am literally just going to use the tunnel and the boot floor to come off of to box just that one area in,

Even if regulations didn\'t deem it just as all my previous race cars I would shield the fuel from me anyway, scares the life out of me when I see FD\'S with a whole fuel system in the back with no firewall and all that fuel pressure going on !:Hammer   .

p.s. if you can\'t see , there is a 12mm link pipe under the swirl pot feeding the pump.

[Martin Price]

Looks good Clive, as you\'ve already said the standard pump is a real complicated affair, we ran a spare one of ours up in a pot of water over xmas to see how shallow it would pump, after some head scratching we opted for bypassing the pump regulator and filter, cutting vee\'s round the bottom of the pump housing to let fuel in and piping the pump straight out the top of the pump housing

[clive]

Martin,

If you use this type of system you may well find you have to address the problems I uncovered along with Aston\'s research, in that the stock pot assembly maintains the syphon effect drawing fuel across from the other tank.

One guy reckoned he had a pump in the other tank instead but this must be rubbish because there would be no way of balancing the tanks, i.e. you would just pump one tank into the other.

This is another reason for taking a step back, reverting to the stock pot because the other assembly like yours had the stock regulator removed and its this part of the pot that operates the syphon.

I just blocked off the regulator feed on the balance pipe which I now know was wrong and pre Brands was working on ways of modifying the pot to draw fuel in from the other tank, something I now don\'t need to address.

 

Obviously the stock RX-8 regulator needs removing or it will fight an external regulator, unless of course you only use the stock pot assembly lift to lift fuel to a swirl pot only, hence my backward step.    

hope this helps

[Martin Price]

Hi Clive, I probably should have explained exactly what we’re doing instead of giving you half the info.
Our system comprises of twin pumps in each side of the tank modified as I’ve previously described so they just pump out into our swirl pot, then a return/overflow out the top of the pot back into the top of the tank via a fitting in the top of one of our fuel pump housings.  Then from the swirl pot we go through the filter into our 044 then straight to the fuel rail via the inside of the car, then through the reg back to the swirl pot.
Other than the twin pumps (which we can switch individually if necessary) as far as we’re concerned this is a pretty conventional race car fuel system set-up.
We’ve just been looking at your pictures again and we’ve noticed that we can’t see a return from your pot to your tank. If you’ve removed the regulator from the in tank pump I’d be very concerned about the return from your fuel rail pressuring up, confusing the external regulator and causing all sorts of problems.  You really don’t want any pressure in your fuel pot.
Cheers Martin

[clive]

Hi Martin,

We still have the stock set up in the tank with regulator, just using the pump as a lift pump so that pump will regulate at a lower pressure than the main system.

As with many cars before I am using a 1.1 regulator with the return back to the swirl pot which is the middle pipe in the picture to ensure the swirl pot has extra fuel.

If we have problems during the next test we can quickly revert back to the system we had where we were dumping fuel straight back into  the  top of the stock fuel pot.

[Martin Price]

Hi Martin,

We still have the stock set up in the tank with regulator, just using the pump as a lift pump so that pump will regulate at a lower pressure than the main system.

As with many cars before I am using a 1.1 regulator with the return back to the swirl pot which is the middle pipe in the picture to ensure the swirl pot has extra fuel.

If we have problems during the next test we can quickly revert back to the system we had where we were dumping fuel straight back into  the  top of the stock fuel pot.

Ah I see, we didn\'t consider connecting our system up like that, I just assumed the pressure on the other side of the reg would upset it. Our system might be a bit over complicated with hindsight, we were saying today that we could have probably got away with not running the 044 and swirl pot with us running twin pumps.
Cheers Martin

[Grant Monkhouse]

I\'m still a little confused: Surely you need a return from the swirl pot so when the pot is full it will fall back into the tank? Obviously during a race not much fuel will be returning too the engine but waiting around the pumps will fill up the system and when the swirl pot is full where will the fuel go too?

My fuel return line goes Into the swirl pot but I also have a return from the pot to the tank. An overflow if you like.

Have you thought of a fuel cooler Clive? Cooler consistent temp fuel is always better:D

[clive]

I like simple, (stop laughing at the back):Giggle

Seriously, had I realised the voltage was our problem I would not have fitted the swirl pot and Bosch because we know from years of playing with FD\'s that just the better Walbro in tank should have been sufficient for our power demands.

I initially went for just the in-tank set up because it was simple and I like simple on Race cars as simple and uncomplicated tends to be more reliable, hence our initial set up.  

Like I said, in a way its a step back to go forward and at least we are now back to simple inside the tank that I was still not convinced was not going to bite us the more we tested.

There\'s a huge amount of info on FD power but as you will have seen, there\'s very little on integrating the FD with the FE.

[clive]

Hi Grant,

This may work fine on a bigger swirl pot but I am also relying on a certain amount of pressure in the pot and should I vent this it would potentially loose fuel from what is dumping back into the tank from the vent.

Dont forget my pot looks odd as  I designed it to have the main feed out of the bottom, so normally you would see three pipes out the top.

The other route is to have an in and an out and pipe the return directly into the tank but that way we loose all that extra fuel that will ensure the swirl pot always has a full partially pressurised feed, that will not be as much as the main pressure feed from the Bosch down to the injectors.

I believe we should never need a cooler with the BHP we are going to use.

Hope this makes sense

[Grant Monkhouse]

Ah I get it now, so in theory the slight pressure inside the fuel pot should help push fuel around again.

[clive]

Ah I get it now, so in theory the slight pressure inside the fuel pot should help push fuel around again.

Yes that\'s it :chat