109 replies to this topic

[CHILL Gone DUTCH]

So the pump your offering for supercharged car will be similar output to the walbro 255 But with the advantages you mentioned earlier If there is a type of pump which replaces walbro 340 gst type pump which I'm using direct in tank for a 350 hp + SC setup with SFP + boost can you give details As I've had fuel starvation at zandvoort unless I'm above 3 / 5 of a tank Cheers

Edited by CHILL Gone DUTCH, 28 November 2015 - 08:21 PM.

[Spitfire Engineering]

So the pump your offering for supercharged car will be similar output to the walbro 255 But with the advantages you mentioned earlier If there is a type of pump which replaces walbro 340 gst type pump which I'm using direct in tank for a 350 hp + SC setup with SFP + boost can you give details As I've had fuel starvation at zandvoort unless I'm above 3 / 5 of a tank Cheers

 

Hi

Just a couple of quick questions as I mentioned two options previously.

Do you know what rail pressure you are running? and boost?

Did you fit the Walbro yourself? if not then where?

 

The later question may seem random bit there is a pattern  

 

Ta

Gaz

[CHILL Gone DUTCH]

Running 3 bar static 213 kpa map pressure. ( 2.1 bar) 113 kpa boost pressure (1.1bar)

[JG]

Finally

[Spitfire Engineering]

Running 3 bar static 213 kpa map pressure. ( 2.1 bar) 113 kpa boost pressure (1.1bar)

 

OK so as a working example for all viewers.

We need the base rail fuel pressure 3 bar

And the boost pressure (otherwise the increased air pressure will resist the fuel flow).

 

Maximum needed 4.1 bar x 14.5 = rounded up 60psi

If you use the 60psi line in the pump table you get 438 bhp

 

In this table the last column is calculated from the actual flow at a BSFC of .5

If the engine was NA this figure would be correct.

But for SC you need to correct it to .6

So simply multiply 438 x 5/6 = 365bhp max SC

 

We than add a margin of 15% to allow for wear over time and small drag losses.

 

So NA at 60 psi = 438 x .85 = 372

and SC  "   "      = 365 x .9 = 310

 

This pump will support anything OE and modded up to the figures above.

 

 

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Next option is the more powerful pump which fits the new pump unit (see below)

This is the test result for this unit (lowest results of 15 units tested)

It is much firmer in the higher regions and at 60 psi as above would give...

NA 60 psi = 496 x .85 = 421bhp

SC 496 x 5/6 x .85 = 351

 

 B2 .jpg   159.17KB   6 downloads

 

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After this there is no option for a dual input (non eductor) pump for this unit.

So the last option is a correctly modified, original OE unit with a high quality turbine pump selected to requirements.

 

_______________________________________________________________________

 

Not true of course, the last option is to buy a Walbro pump and fit it yourself………..  

 

Gaz

 

 

 

 

Edited by Spitfire Engineering, 29 November 2015 - 09:35 AM.

[Spitfire Engineering]

Running 3 bar static 213 kpa map pressure. ( 2.1 bar) 113 kpa boost pressure (1.1bar)

 

You didn't mention what the pump situation is at the moment?

U2U if you prefer.

 

Gaz

[Spitfire Engineering]

Should have mentioned the higher output pump (HOP) is not priced yet as I need to accurately gauge the conversion time.

The sharper ones amongst you will have noticed the amp draw of the HOP is even less that the new units standard pump.

This is also a turbine pump and the most efficient pump we have ever tested. Remember a portion of the output is forced back through the centre of the turbine to charge the canister which this does in 4 seconds by the way, same as the standard pump.

 

Gaz

[Exmantaa]

Running 3 bar static 213 kpa map pressure. ( 2.1 bar) 113 kpa boost pressure (1.1bar)

 

@ Chill; never new you modded your regulator for 3 bar static fuel pressure. Does the later OBD-Tuner support that, or you got a special 3 bar calibration from Peter?

[CHILL Gone DUTCH]

From memory it's the gst 450 pump The housing did need a light modification to get it in The Harrop SC cars are getting close to producing 400 hp plus a bit more And producing up to 2 bar of boost pressure Don't know if it matters but water injection is also going to be used next year by a few Is there a alternative pump available to do this ?

[Exmantaa]

edit

Edited by Exmantaa, 29 November 2015 - 11:24 AM.

[CHILL Gone DUTCH]

Running 3 bar static 213 kpa map pressure. ( 2.1 bar) 113 kpa boost pressure (1.1bar)

  @ Chill; never new you modded your regulator for 3 bar static fuel pressure. Does the later OBD-Tuner support that, or you got a special 3 bar calibration from Peter?

? I thought static fuel pressure was 3 bar standard

[Exmantaa]

Ehhhh, you really need to start reading this topic...

[smiley]

@Gaz; we have various configurations out there. From highly tuned NA, up to SC conversions that either use oem or saab material for fuel rail and fpr. SC conversions also connect the manifold to the fpr, adding pressure at full monty. As that that can also vary, depending on pully size, we have a lot of variables in the end on pressure in the fuel rail. 

 

[smiley]

 

_______________________________________________________________________

 

Not true of course, the last option is to buy a Walbro pump and fit it yourself………..  

 

 

That has been done a lot of times over the years.

We have not yet seen fatalities or broken engines on this.

 

Edited by smiley, 29 November 2015 - 11:38 AM.

[Spitfire Engineering]

 

 

_______________________________________________________________________

 

Not true of course, the last option is to buy a Walbro pump and fit it yourself………..  

 

 

That has been done a lot of times over the years.

We have not yet seen fatalities or broken engines on this.

 

 

 

Hi There

I don't think anyone has suggested they may cause a crash? or destroy an engine.

But we have seen cars with fuel starvation, start problems and most are noisy.

As mentioned we changed four over last year from poor conversions, it is not as simple as making the pump fit!

 

Edited by Spitfire Engineering, 29 November 2015 - 12:37 PM.

[Spitfire Engineering]

From memory it's the gst 450 pump The housing did need a light modification to get it in The Harrop SC cars are getting close to producing 400 hp plus a bit more And producing up to 2 bar of boost pressure Don't know if it matters but water injection is also going to be used next year by a few Is there a alternative pump available to do this ?

 

So same details as above?

power?

future proof power? i.e at 2 bar boost?

 

[Spitfire Engineering]

@Gaz; we have various configurations out there. From highly tuned NA, up to SC conversions that either use oem or saab material for fuel rail and fpr. SC conversions also connect the manifold to the fpr, adding pressure at full monty. As that that can also vary, depending on pully size, we have a lot of variables in the end on pressure in the fuel rail. 

 

 

Yes, seen quite a few today  

At the end of the day with the info supplied, you should be able to work it out or at least use blanket figures i.e under 400 NA = new unit etc

 

But to use the above example 

It runs at 3 bar plus boost 1.2 = 60psi max

It produces what? 360bhp?

 

So we need 360 x .6 = 216 lbs/hr = 137lt/hr at 60psi.

we want a margin of at least 10% better 15% so thats now about 158lt/hr

 

The GST pump fitted at that pressure supplies 381lt/hr!

Can you see what a phenomenal miss match that is?

220 lt/hr are recirculated from the pump to the engine and back into the pump unit canister again, and thats only when at full power, for the rest of the time it is probabaly closer to 300lt/hr.

 

So completely the wrong pump to use and the unit was never correctly adapted to receive it either. Making it fit isn't adapting the unit.

Does it have problems = yes

Do you have to tank the tank out and start all over again = yes

So was it a good option just because it appeared to be cheaper?

 

You decide that one!  

 

 

 

As an alternative this pump supplies the following and we have used it in at least 40 conversions since we swapped over from Walbro, all successful, all still running ...

 

 T255 .jpg   177.66KB   3 downloads

 

Now you can see the 60psi line gives a flow of 217lt/hr

it is still high but not stupidly, it will cope with a boost upgrade of 2 bar nicely

 

If we go on further and look at 400 bhp as mentioned.

400 x .6 = 240lbs/hr = 151lt/hr + 15% = 174lt/hr

However we have increased the boost from 1.1 to 2.0, total 5 bar now = 72.5psi

Using just under the 75 psi line = about 200lt/hr so still more than enough fuel, but now a more sensible margin of 30% total.

This pump only uses around 12.5A not 17A of the Walbro and can safely be used on the vehicles existing wiring.

 

Gaz

Edited by Spitfire Engineering, 29 November 2015 - 01:49 PM.

[Exmantaa]

Gaz,

 

Chill was probably wrong and he still uses the stock 3.8bar regulator. Plus 1.2 bar boost pressure, so he is at 5 bar/ 72psi railpressure @ max power in your example...

[Speedy4Fun]

And producing up to 2 bar of boost pressure Don't know if it matters but water injection is also going to be used next year by a few Is there a alternative pump available to do this ?

 

2 bar of boost with a Harrop?

You are way out of efficiency, only pumping hot air and don't think the piston rings will like it.

I wouldn't go higher then 1.35 bar boost.

Get the intake temp down that will make power!

[CHILL Gone DUTCH]

Not me I'm sticking to at lot less than that Was thinking more for the 2.0 harrops on a small pulley with water/ meth injection