Stack ST8130

[stig]

I intend to fit the Stack integrated dial instead of the Ultima ones as I like the info. to be in front of me.

I have a question regarding the best way to connect up the fuel senders and pumps?

I have a 2 tank system with the twin senders yet I gather that the Stack can only take one sender feed.

The factory gives 2 options, either link the tanks at low level (thereby equalising the levels in both tanks so a feed can be taken from either one) and two pumps feeding the carb or, link the two tanks with a 'T' and use one pump to feed a surge tank and another to pump to the carb.

Any recommendations?

Cheers

[gdr]

Stig,
I've been thinking about the same problem, despite having VDO fuel gauge. Seems a bit of a waste using twin pumps when only one works at a time. I'm looking at a single Holley 12-802 feeding from one tank with the tanks linked at low level - but then I've only got 410 HP or so. Suspect to pour fuel into your 600 HP monster you might be better with low link pipe and a pump on each tank, feeding into a Y block or surge tank with regulator downstream on line(s) to carb(s). Holley website has some schematics.

[stig]

Thanks gdr. Have spoken to Gail at American Speed about the fuelling requirements and he says that the 600hp doesn't actually need a great deal more fuel than a standard 350 and that the Carter P4600HP pumps that Ultima supplies are fine.

This doesn't solve the layout issue though, but at least the pumps are stock.

[ultimaandy]

Stig

I have a STACK 8130 and only use the drivers side sensor.
I also linked the two tanks together using a -12 fitting which I had welded to the tanks prior to fitting. This didn't cost much and means I can fill from one side of the car as the tanks level as you fill.

If you use the existing -6 fittings to balance the tanks you will have to fill up both sides as they wont balance that quickly.

The fuel pump problem was then solved by using a dedicated blue holley (which is like a tap!) with a T to both tanks. This works well as the bottom 8 litres of the tanks can not balance out so when you get low on fuel (below 20litres) there is an equal amount in each tank to be emptied.

Mine is a 526Bhp american speed so should be OK for 600Bhp, although the regulator can be a bit noisy (until you start the engine when you can't hear it!)

[stig]

Andy - did you get the -12 fitting welded in by a fabricator or did the factory do it?

Just got off the phone to Ted and he told me that they'd only ever made 2 tanks with -8 fittings (Gareth's and Adequatespeed)

[GTRCLIVE]

Hi There Stig. I've been a V8 owner for more than a few years and one tip I've picked up on is that the Standard -6 Hose's are not enough for a 600 BHP track car. As with most things American there is no such thing as to BIG a Fuel supply. -8 ( 10mm Bore ) hose if you use a Single Pump is just enough, Twin Pumps with -8 Hose is better.
I'm running a Single Holley Blue top( 140 GHP Version ) with Holley fuel pressure regulator, and feeding each fuel boul with a seperate -8 line (regulator has two outlets) with about 440 BHP. The pump is run off a Tee into both tanks, and the tanks are balanced top and bottom, but all hoses are -8 (ps made my own tanks, with all -8 Fittings, standard all -6).
My second car (allready Started, 600 BHP Hopefully),I'll be useing twin pumps twin Pressure regulators, tee'd after regulators ( to balance pressure difference's) with idividual fuel line's to each float boul.All -8.
With this setup i can run one pump for the road a two for racing. Have Motec ECU, that can sence fuel pressure drop, and will turn on second pump if it needs it.But two switches on dash Cheeper.
Stack 8130 is controling one tank level probe.Andy -12 balance pipe makes this alot better.Will incorperate this in next car, as am running Stack again ( Motec dash nearly 3K to expensive)
Have pic's if you want. Will be at Donnington on Sunday, email me if you want to swap Phone numbers.

Keep on wooping those Italian things---- Love it

[adequatespeed]

As for Fuel pumps

The last thing you want is fuel shortage as it wil result in a lean run and a meted engine.

I STRONLGY suggest for 600Bhp you go for an uprated fuel pump. At leat 100gallons per hour.

I have a 450bhp engine and my engine builder recomended -8 pipes throughout (not -6 as used as standard) and a holley blue fuel pump. Not had any problems at all.

I am using a single pump connected to both tanks via a Tee fitting

[stig]

Thanks chaps. Have spoken to American Speed and Ted about this and they both feel that the Carter pump is fine and so are the -6 feeds.

So who do I believe? I can certainly see the sense in going for a larger outlet especially from the perspective of balancing the tanks.

I'm taking the rolling chassis to the factory next week to have the bodywork prefit (don't trust myself to do it well enough!) and I'll no doubt be talking to Ted at length about it then.

I'm so pleased that this forum has become, and continues to be so active and a great place to share this information.

Keep up the good work lads!

[polson]

The dyno plot for my American Speed 540 Enforcer shows that the 800CFM carb is showing a peak fuel flow of 190 lbs/hour, that is equivalent to 23 US GPH. So a 140 GPH pump seems to be over doing it a bit.

I realise that the demand could be higher for certain transients, and that if during a long corner you are picking up air you want to catch up as soon as possible, but that seems like overkill.

If you have ever started your car without the fuel pump on you will know that you can drive (not idle) for almost a minute before it splutters, suggesting the carb bowl has adequate reserve for most bends. I say go with what Gail says and by all means fit a -12 balance pipe.

Anyone know the fuel pump configuration on the Colin Blower car?

[LRdriver]

Having messed around with K series rover engines, this V8 lark will be a whole new area for me.. so imagine my luck that there is a guy here in b-stortford who specializes in US cars and engines.. apparently he is in a team that runs funnycars and came second at santapod last week, so I will be using him for engine stuff. he is less than a mile away from me so pushing it there is always an option

(sorry to hijack the thread..)

[james]

I'd definitely fit a swirl pot, whether you have 2 LP pumps filling it from both tanks, or a single LP pump filling it from one with a balance pipe. As somebody just mentioned, if you take it onto the track and you get a lean mixture, even for just a few seconds, you can do a lot of damage to the engine.

I only have 1 (rather large) fuel tank, but it has 2 LP pumps filling the swirl pot (one pumping from each side), and a single HP pump pumping it up to the engine. I use -6 pipes throughout the whole fuel system, and that's fine for my little engine.

[james]

quote:
Anyone know the fuel pump configuration on the Colin Blower car?

I do know that he was having a hell of a job with it last season. I was chatting to him at Knockhill, and he said that they were having trouble getting the last 40 litres out.

[ultimaandy]

My tank has standard -6 fittings a-la factory.

I had the -12 welded on by a local firm and then pressure tested them again myself (factory recomend this anyway and so do I, imagine finding a leaking tank after side pods fitted!).

If we see you at Donnington we'll show you

[G Man]

I saw Colin's car and it had bag tanks, and there were going to move them to the storage bay area

[GTRCLIVE]

quote:
The dyno plot for my American Speed 540 Enforcer shows that the 800CFM carb is showing a peak fuel flow of 190 lbs/hour, that is equivalent to 23 US GPH. So a 140 GPH pump seems to be over doing it a bit.

I realise that the demand could be higher for certain transients, and that if during a long corner you are picking up air you want to catch up as soon as possible, but that seems like overkill.





Dear Sir,
just speak to Pete Knight Racing, he has personaly seen the inside of a few Ultima engines that have ran the standard fuel setup. If your still not convinced please run your car on two Facet pumps,
(they deliver more than 23 US GPH) and do some racing.
Pete Charges about 3K to do rebuilds.

Good luck.

ps. The reason these forums are so valuable is that you can learn from others mistakes !! Not repeat them.
Have fun.

>> Edited by GTRCLIVE on Thursday 12th September 20:26

[ultimaandy]

quote:
Have spoken to American Speed and Ted about this and they both feel that the Carter pump is fine and so are the -6 feeds.

So who do I believe?

STIG

There are many ways of doing this, the factory is one, mine is another, clive's is another, james etc.....

It all depends on how much you want to do yourself, I wanted to do everything I could, so didn't want to just buy off the shelf and have kitted out the engine bay my way. This may not be for you.

However it needs to be right so err on the edge of overkill as just enough won't save money (my set up was same kind of money as factory) but could cost you an engine!

Just remember the factory want you to stay with their layout..........and fuel like oil must be right on your expensive engine.

[james]

Andy,

I completely agree with you there. It's worth the extra minimal investment to have the capacity to provide too much fuel to the engine. That's what pressure regulators are there for. The setup I have delivers more fuel than the engine will ever need. I'd rather pay £100 for some extra plumbing and a higher spec fuel pump than pay out for an engine rebuild.

James

[LRdriver]

James,
is the ultima elegible to compete in the JCC centurion races?

[ultimajohn]

Qoute:
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I have a 2 tank system with the twin senders yet I gather that the Stack can only take one sender feed.
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I built my Ultima in 1995/6. At that time the Stack wouldn't accept switching the feeds with a centre off 2pole switch. I was assured in 1997 (when Stack replaced the unit under warranty) that this was a software problem and it was fixed. I had already fitted a switched VDO gauge so didn't bother to pursue it further. Ask Stack for current position.

I run the offside tank to feed the engine via the high pressure fuel injection pump, which is inturn fed from an anti surge tank. The injection pressure regulator return comes back to this tank. The nearside tank contents are just transferred across the car when needed by a standard pump. Its just a big reserve. A warning light on the dash reminds me that transfer is taking place. It works for me.

[polson]

quote:

Dear Sir,
just speak to Pete Knight Racing, he has personaly seen the inside of a few Ultima engines that have ran the standard fuel setup. If your still not convinced please run your car on two Facet pumps,
(they deliver more than 23 US GPH) and do some racing.
Pete Charges about 3K to do rebuilds.

Good luck.

As far as I am aware the current factory pumps are Carter pumps rated at 100GPH. This is certainly what I was given in Feb 2001, and is currently fitted to all factory cars I have seen.

I also note that all current factory demonstrators run American Speed engines (and have done for the last 2 (?) years). I also note that the factory have only had one demonstrator with a Knight Engine.

If you want to tell me that the factory like their demonstrators to melt pistons, and that they have less experience of their customers installations than Peter Knight, then go ahead.

Let's face it when most of us spec our cars up we'd like to think that we are going to enter the Le Mans 24H, but realistically how many of us actually end up in race conditions? I don't really think that the odd track day is anywhere near race conditions.

p.s.: I can't believe that a question about fuel senders has deviated to a debate about required fuel flow.