Performance Difference

[309PUG 2 1 Cars]

Hi,

 

After a car has been on the rollers mapping your DTA etc, would there be any performance to be gained by running 3bar fuel pressure instead of 2bar ??

I think the answer may be yes, but how much more bhp / lbs could be gained ??? 5% or 10% or is it more like 1%

 

Chris

[Craigb 2]

Surely you would also need additional air to accompany the fuel see a gain?

 

the only benefit could possibly better atomisation .

 

apart from a situation where the injectors had been maxed out and the engine running too lean?

[petert 607]

Convert into psi, then divide by the square root:

 

3bar = 43.5psi

2 bar = 29psi

 

43.5^0.5/29^0.5= 6.6/5.4 = 1.22 or 22% richer

Edited June 19, 2007 by petert

[309PUG 2 1 Cars]

Convert into psi, then divide by the square root:

 

3bar = 43.5psi

2 bar = 29psi

 

43.5^0.5/29^0.5= 6.6/5.4 = 1.22 or 22% richer

 

 

So if it could run 22% richer so to speak, if the engine was re mapped at the new fuel pressure of 3bar, what performance gain could be yielded ???

 

Chris

[petert 607]

I'm not sure why you'd run at 2 Bar anyway. That means under vacuum, you could be as low as 1.2 - 1.5 Bar, which is very poor for atomization. Remember that the pressure is relative to the manifold vacuum. I'd much prefer to do the mapping at 3 Bar.

[309PUG 2 1 Cars]

I'm not sure why you'd run at 2 Bar anyway. That means under vacuum, you could be as low as 1.2 - 1.5 Bar, which is very poor for atomization. Remember that the pressure is relative to the manifold vacuum. I'd much prefer to do the mapping at 3 Bar.

 

I couldn't agree more about mapping at 3bar, unfortunately my mapping was done at about 2.2bar, we only noticed it after the event, we all forgot to check it at the time. So back to my original question, would I gain any more performane by getting it remapped at 3bar or is it not worth while ???

 

Chris

[Sandy 191]

Extremely unlikely.

[d-9 0]

You'll get an extra 34bhp.

 

 

Would've thought it depends on wether ur injectiors are maxing at 2.2bar, if so then you could get more power but otherwise I'd have thought it wouldnt make that much of a differnce

Edited June 21, 2007 by d-9

[309PUG 2 1 Cars]

D 9 Where the heck do you get 34 hp from ??? although the thought is nice.

 

My injectors are not maxed out at 2.2bar.

 

Okay it's 15 all so far, one says yes one says no, anyone else care to add there opinion.

 

Chris

[boombang 2]

Of course it wouldn't gain power unless it was running lean, you would just make the engine run richer and lose power.

 

Possible damage:

 

foulling of plugs (causing missing)

bore wash (piston ring wear)

oil contamination (reduced lubrication throughout whole of engine)

 

If however you upped fuel pressure and remapped to suit, you may gain from better atomisation, giving better burn, better low running and pickup etc.

Edited June 21, 2007 by boombang

[deadcatdave 0]

Of course it wouldn't gain power unless it was running lean, you would just make the engine run richer and lose power.

 

Absolutely, isn't it obvious this would happen? It's always a good idea to have an adjustable regulator and gauge before you get your mapping done.

[309PUG 2 1 Cars]

Of course it wouldn't gain power unless it was running lean, you would just make the engine run richer and lose power.

 

Possible damage:

 

foulling of plugs (causing missing)

bore wash (piston ring wear)

oil contamination (reduced lubrication throughout whole of engine)

 

If however you upped fuel pressure and remapped to suit, you may gain from better atomisation, giving better burn, better low running and pickup etc.

 

So is that a yes ?? better performance if re mapped at 3bar ???

[309PUG 2 1 Cars]

Absolutely, isn't it obvious this would happen? It's always a good idea to have an adjustable regulator and gauge before you get your mapping done.

 

I do have an adjustable FPR and a means to measure the pressure, we simply overlooked the matter until days later.

 

Chris

[deadcatdave 0]

So is that a yes ?? better performance if re mapped at 3bar ???

 

it's only a yes IF it was running lean. On the basis you've just had it remapped the the mapper undoubtedly used an AFR meter, it's very unlikely you'll see any difference. Does your graph show the AFR on it ?

[309PUG 2 1 Cars]

it's only a yes IF it was running lean. On the basis you've just had it remapped the the mapper undoubtedly used an AFR meter, it's very unlikely you'll see any difference. Does your graph show the AFR on it ?

 

Hi,

The graph does not show the AFR but I do know it is running ever so slightly rich if anything. If in that case my engine at 2.2bar is NOT running lean why bother running 3bar fuel pressure ?

 

Chris

[boombang 2]

Better atomisation of fuel would be one - kinder on the engine and should help pickup at lower engine speeds.

 

Basically should help to give a more complete burn as fuel

 

How much difference it makes is a different matter, but tbh I can't think of any injection cars that run fuel pressure as low as 2bar.

[309PUG 2 1 Cars]

Better atomisation of fuel would be one - kinder on the engine and should help pickup at lower engine speeds.

 

Basically should help to give a more complete burn as fuel

 

How much difference it makes is a different matter, but tbh I can't think of any injection cars that run fuel pressure as low as 2bar.

 

Okay then, do I really need to remap the engine if I upped the fuel pressure to 3bar ???

 

Chris

[Sandy 191]

Yes, please don't screw about with it, without a proper handle on what it's doing to the air fuel ratio.

[deadcatdave 0]

chris, have you considered running a wideband display ? very handy for a track/race car.

[Pugnut 9 1 Cars]

like this one ?

 

here