Jump to content
The mkiv Supra Owners Club

Fuel System Setups!


JamieP

Recommended Posts

Guest Cody Phillips

Jamie,

 

IMO I would definitely stay away from the triple Walbros, the more fuel pumps you have in the system the less reliability you have. Ultimately it depends on your end result goal for HP levels. You'll never use up the Weldon's potential ability and with a voltage controller it makes the sound very quiet. Running twin 044's works well but you've got a lot of fitment issues to make it work, plus you'll need to buy a total of four filters and many more fittings to make it work. It ends up being kind of a cluster when it's finally installed. I prefer to run the 044's externally, rather than in the tank, especially if you're running E85 because the pumps don't stand up to the corrosiveness for very long. Bottom line, stay away from the triple walbro (those were cool in 2005), and the less complicated the fuel system, the better off you'll be in the long run.

Link to comment
Share on other sites

  • Replies 100
  • Created
  • Last Reply

Top Posters In This Topic

Guest Cody Phillips
Just bought some high imp injector dynamic 2000cc injectors, rated as the best available it seems.

 

These work well, but probably an overkill for current build. You could've ran ID 1,000s :)

Link to comment
Share on other sites

I can tell you the stock pump connector in the tank top fitting is not up to running even one 044 without the risk of the contacts overheating, let alone two. You need to use feed throughs to seal the leads and bring them out of the tank in one piece, and connect externally with a high amperage connector.

 

A swirl pot is good insurance for track days, probably not so much for drag racing if you have plenty of fuel in the tank.

Link to comment
Share on other sites

I ran a fuel cooler on my MK3. It had an interesting side effect that I had to reset the cold start fueling map as the temperature difference was such it provided it's own enrichment. I think 25row x 235mm -6 core was probable overkill but it was what I had left over when up sizing the oil cooler core with -12's. One trick I used was to T the rail fuel return to back to the tank as well as the swirl pot as this can reduce the fuel temp. Swirl pot sizing is very important. Nathan Freke had to add extra volume to his on his drag MR2 as the twin 044's were emptying it faster than the lift pump could fill it.

 

Best option is always a pump that can supply the engine demand, anything else is compromise. Having twin fuel entry on the fuel rail with no pulse damping has always been something I've tried to avoid too. All those pressure waves colliding in the fuel rail must cause localised pressure spikes in the rail which could make an injector push a little more fuel that it would normally making for very interesting AFR balance issues.

 

I could be just talking bollocks though :D

Edited by Nodalmighty (see edit history)
Link to comment
Share on other sites

Worth considering the wiring used regardless of what carlos fandango pump you select , the supply cable needs to be a quality cable due volts drop and the earth cable is often neglected ,everyone assumes that if bolted to the chassis all must be good - the cars are old and earth cables aint what they were new !

you could have high resistances at the main chassis earth ,worse varying resistances , now with the pump under load you get varying voltages and outputs , consider a separate earth wire back to battery or main earth -cheap as chips

Link to comment
Share on other sites

I ran a fuel cooler on my MK3. It had an interesting side effect that I had to reset the cold start fueling map as the temperature difference was such it provided it's own enrichment. I think 25row x 235mm -6 core was probable overkill but it was what I had left over when up sizing the oil cooler core with -12's. One trick I used was to T the rail fuel return to back to the tank as well as the swirl pot as this can reduce the fuel temp. Swirl pot sizing is very important. Nathan Freke had to add extra volume to his on his drag MR2 as the twin 044's were emptying it faster than the lift pump could fill it.

 

Best option is always a pump that can supply the engine demand, anything else is compromise. Having twin fuel entry on the fuel rail with no pulse damping has always been something I've tried to avoid too. All those pressure waves colliding in the fuel rail must cause localised pressure spikes in the rail which could make an injector push a little more fuel that it would normally making for very interesting AFR balance issues.

 

I could be just talking bollocks though :D

 

I think it largely depends on your base pressure. If you have a relatively low base pressure, then the change in pressure that you would see at the injector when it opens will, I imagine, have a reasonably high effect. If you have a reasonably high base pressure, then I think it will help to smooth those effects out.

 

Fuel temperature is quite a 'hot topic' in F1 at the moment. Mainly due to a regulation that prohibits any direct cooling of the fuel or tank, but there are very clear performance gains for doing so.

Link to comment
Share on other sites

What would you recommend as a good fuel setup for something like Jamie's car, Chris?

 

I wouldn't want to run huge injectors just to future proof alcohol fuels. I'd probably bite the bullet and run two injectors per cylinder so as to keep excellent low flow atomisation and control. Then run to only run the secondary ones when needed. Pump wise I wouldn't touch anything other than Bosch or engine driven mechanical. I would run a swirl pot if the car is to do track work. I run a big home made pot in the Skyline, with twin 044 pumps, one is just a back up though, I found at my power level I didn't need the second one, but as it was there I left it. I have to move the car in a bit, I'll grab a photo.

 

Oh, and as for cooling my single pump set up, even with a swirl pot of well over a gallon capacity, still heats the fuel badly. When I move this stuff to the new shell I will have a fuel cooler, in the return, but I will want to site it somewhere very safe, probably under the car with ducting to it. Rouse did this with the Group A Sierras, I'll probably just copy him ;)

Edited by Chris Wilson (see edit history)
Link to comment
Share on other sites

Fuel temperature is quite a 'hot topic' in F1 at the moment. Mainly due to a regulation that prohibits any direct cooling of the fuel or tank, but there are very clear performance gains for doing so.

I remember the big fuss at the Brazilian Grand Prix a couple of years back about this. It's got to be a few degrees relative to ambient hasn't it?

Link to comment
Share on other sites

I wouldn't want to run huge injectors just to future proof alcohol fuels. I'd probably bite the bullet and run two injectors per cylinder so as to keep excellent low flow atomisation and control. Then run to only run the secondary ones when needed. Pump wise I wouldn't touch anything other than Bosch or engine driven mechanical. I would run a swirl pot if the car is to do track work. I run a big home made pot in the Skyline, with twin 044 pumps, one is just a back up though, I found at my power level I didn't need the second one, but as it was there I left it. I have to move the car in a bit, I'll grab a photo.

 

My head is battered with all of this!

I don't fancy twin injectors per cylinder, but there again, I've no plans for E85 or exotic race fuel, just Shell Vpower and the like for me.

I need to go away and think.

Link to comment
Share on other sites

When I move this stuff to the new shell I will have a fuel cooler, in the return, but I will want to site it somewhere very safe, probably under the car with ducting to it. Rouse did this with the Group A Sierras, I'll probably just copy him ;)

 

That's where mine was, in front of the passenger wheel behind the front bumper with a big metal plate under it and mesh in front of it so no stones could get near it. My Oil cooler must have been quite jealous.

Link to comment
Share on other sites

I remember the big fuss at the Brazilian Grand Prix a couple of years back about this. It's got to be a few degrees relative to ambient hasn't it?

 

No less than 10 degrees below ambient rings a bell. Seeing as the fuel tank is bolted to the front of a V8 at 19,000rpm for 2 hours, unless you have something fairly obviously underhanded I think you'll struggle to get it below that.

Link to comment
Share on other sites

That's where mine was, in front of the passenger wheel behind the front bumper with a big metal plate under it and mesh in front of it so no stones could get near it. My Oil cooler must have been quite jealous.

I'm NOT too mechanically minded, but that sounds a bit scary - if you have an 'off' or someone hits you and the front is badly damaged, the cooler would be burst and fuel would be splattered all over the place, including the hot engine bay, no?

Link to comment
Share on other sites

I'm NOT too mechanically minded, but that sounds a bit scary - if you have an 'off' or someone hits you and the front is badly damaged, the cooler would be burst and fuel would be splattered all over the place, including the hot engine bay, no?

 

Academic really, the car was cubed after about 100 miles (as it was total shite). However, that could be true of any location on the car. Also a big enough shunt could shear the fuel lines giving you the same problem in any car. It's one of lives little lotteries that you don't want 6 number on I guess!

Link to comment
Share on other sites

Academic really, the car was cubed after about 100 miles (as it was total $#@!e). However, that could be true of any location on the car. Also a big enough shunt could shear the fuel lines giving you the same problem in any car. It's one of lives little lotteries that you don't want 6 number on I guess!

What sort of capacity is the cooler though? True a fuel line contains fuel, but a minimal volume, and the lines are as well protected as possible, being towards the centre of the car (front/back and left/right).

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. You might also be interested in our Guidelines, Privacy Policy and Terms of Use.