one thing to keep in mind, and this is where it gets confusing to me, with increasing options of mods giving honest increase in power plus R compunds,Plus suspensions,plus drivers getting better--all equals to the need for a stronger fuel delivery system. Once experienced this is an issue I dont ever want again--can be real dangerous on the track.
So which will it be:
1- Replacing the stock pump may solve this problem for a limited time and if no more mods happen to the car etc. cost approx $180-200?
2- go with Mazsports plug and play mod and have no worries up to 400hp--cost approx $400 after core rebate. approx $200 more for no more worries at all.
3- go with a Dannobre oridginal remedy and also it seems no more worries--cost unk but probably less than Scott's.
HMMMMM.
olddragger

 

Scott's is $599 plus a refundable core charge.

It might not be the best for a NA car without tuning...as it uses a rising rate pressure regulator. The stock fuel system might not like the variation in FP when it doesn't expect it.

Changing the FP results in mixture changes.......Youi would have to ask Scott if it will work NA with the stock ECU. I'm sure it will work awesome with the IntX and some tuning

 

I am going to change the stock pump with another OEM unit. If that fails to fix the issue, I will use the old pump in addition to the new one I guess. Thanks for your response.

 

good point dannobre--i also realized after i point out that scotts mods really has not been proven to fix this issue. its more of an upgrade for fi.
After all is said and done --you know i am not totally convinced that my problem is fuel starvation. I mean with my pr0blem there is no hiccup, no skip, no sputter, the engine just dies as if the ignition turned off and then no sputter, no hiccup, no hesitation--she is back on full power. Same place on ONE track and I know I am pulling just as many G's in other left hander's. it is really very strange. Before I do anything radical here I have to do more research.
olddragger

 

That's exactly what mine did...it just died...and then came back on after the G-load dropped.

Maybe the pump is cutting out?.....It stuttered sometimes as well on less severe corners, and acted more like fuel starvation normally does.

It would only do it on long sustained Lefts at first at 1/2 tank or below. After a while it got worse, and would do it when the tank was almost full.

The new pump fixed it down to about 1/4 tank...and with the second pump Iwas good to almost fumes before it would quit

 

thanks dannodre--good to know. Mines a little stranger as that is the only corner on any track i have ever had any issues with. even with a FULL tank of gas. The 1st lap was uneventful but from that point on well----
A simple T pickup one on passenger side --one on driver side wouldnt work?
olddragger

 

There is no real way to add a pickup tube that goes to both sides...esp with the stock setup.

The fuel level system uses 2 levers...and assumes that the passenger side tank is empty when calculating the level on the lower end of the tank from what i can see.

You will see how it works when you pull it out....the passenger tranfer is a siphon from a venturi that is driven by the fuel pressure regulator outfall.

 

ok thanks for the feedback. i wonder if any of the fi boys are tracking? I havent heard. and if they are what are they doing for upgrades.
oD

 

Also remember the old dirt track and circle track boys used to build a "false mini surge tank" by putting the biggest dang tube they could find for the gas line--effetively adding in some extreme case 1 gal to their capacity. I would not want to go with that big of a line with an fuel injected car but I was wondering if you just added a bigger line would it not give you enough gas to get through our problem area and then the pump could catch up? Could that be a simple fix for us non regulated track guys?
I like your system--seems more solid than others i have read about--but not ready to go that complex route yet. I have to have a solid system --dont mention it(so I post about it--right) but I plan on going with the afsc and with that much on the engine i damn sure i dont want any lack of fuel.
thoughts?
Olddragger

 

that won't work or fuel injection without a second scavenger-type pump further up stream, once you lose fuel pressure you're done with EFI regardless of the tube size, the NASCAR engines use an engine-driven suction pump to feed an atmospheric carb bowl, what you need is a small reserve tank between the pump and the EFI with an auto air bleed devise, alternatively you could use a small secondary tank supplied by a low pressure pump which then serves as the feed for the high pressure pump but it gets complicated with an in-tank system

 

Bingo!---thanks team--i complety wasn't thinking of that. Pressure has to be there and if the pump aint sucking fuel --- there will not be any pressure---looks more and more like i too will be doing the bmw fix like Dannobre BUT using Mazsports set up as primary--why isnt anything easy for me---damn.
Appreciate the focus--thinking too hard of a way out.
olddragger

 

You will probably have to run the regulator different on Scotts...ie without the Vac presure adjustor attached??? The Fuel pressure is designed to rise in his setup when the manifold gets pressurized........

Duh...when I was typing this I answered my own question....no positive pressure = no rise in regulator output.....Double DUH for it being way too early on a Sat morning

 

seems like we think alike at times
i do want to get this sorted out before the afsc is offered.
olddragger
.

 

I think I have firgued it OUT!
How about a Top mounted baffle inbetween tanks? It would slow the sloshing enough to not allow the starvation issue---wouldnt interfer with filling etc.
Trouble is--how hard is it to crack the tank and do?
thoughts?
OD

 

Would be hard to do I think.....Speedsource mods the tanks somehow i think.....but they make the fuel guage inoperative at the same time....might not be a problem that is hard to fix.

I can live with OK down to 1/8 tank......

I'm also not totally sure it's a slosh thing...it might have something to do with how the pump pickup works....It might run the "little cup" out of fuel...and be unable to refill it....you would have to look at your pump to figure that out I think why my 2X pump works is that it has twice the reservoir before the pumps run out of fuel??

 

Speedsource won't guarantee the fuel gauge working after their mod. They also have said, at least in the past, they provide the modified tank for track cars/track use only. I can say with careful positioning of the parts, one can retain use of the fuel gauge. FWIW, I can now run the car on the track down to almost the reserve line without fuel starvation. Before, with MPSC and Dunlop SSR 255 and 265/35's x 18's I could, would and did have fuel starvation issues with as much as just under one-half a tank in the car. As fast as these cars chew up fuel on the track, i.e. I'm getting something like > 10 mpg under track, being able to confidently run the car without having to refuel every session is well worth the cost of getting this issue fixed. Having your car suddenly lose power or "surge" then lose all power in the middle of high speed sweepers, with other cars in close proximity to your rear bumper is not something to be enjoyed. It's a hazzard.

 

I concur--I am not tracking my car until this is fixed. It is very puzzleing. Deductive reasoning list
1: I ran the same track(Roebling) several times before and even let a certified driver take it out and had no issues--even at 1/2 a tank.
2- then a few months later another track w/e and sx's show--controllable by lowering the RPM and throttle position--same track--on the same turn --shown 1st when i had about 1/2 tank
3- i did another track even --this time at road atlanta--no issues even at below 1/2 tank. and we were running hard
4- back at roebling a few monthes later and after the 1st lap --even with a FULL tank on one particular turn(double apex left hander immediatly after a short r hander--i go a DEAD engine for about 50 yards as I am exiting the l hander---nothing i could do would stop this--lower rpm, partial throttle---nothing. But it didnt get any worst as the gas got lower in the tank( i contunied to run-- but when traffic was around i would wave them by)
Never have had this problem anywhere else.????????? So in my case it seems to be a progressive problem.
If it is a cup issue why that one spot when other left handers pull more G's and are even longer?
Since it is a double apex there it is a "sudden" change in direction therefore this made me think of the slosh possibility.
still researching this--scotts system may work because it does convert to a return type system and the pump is stronger. if anyone else has any experiences or solutions please join in.
dannobre your system is the only one i know of that fix's this!
saga continues
olddragger

 

I would think that the stock pump is crapping out...that's about the same chain of events that mine had.....I thought at the time it was me going faster and pulling more G's..but I think it was the pump. You can solve it by putting in a surge tank....A tank that is inline...pressurized with another pump. That will solve it as well.

I would go with the new stock pump and I think that it will probably work.

I also think that the Mazsport pump should work as well.......but until one of us does it and tests it at the track...back to back with the non-working one, we won't be sure

 

yep. enough said--appreciate your help and if you hear anything else let me know and i will do the same.
od

 

well damn-- i was checking mazsports fuel pump upgrade and it is more expensive that i thought. I was thinking it was $600 with a core charge of $200 making it a $400 upgrade and that was workable. But a $600 upgrade--I dont think so.
oldragger

 

I'd like to include myself in the "fuel starvation problems". LH high G corner had me thinking that I was already hitting the rev limiter. I looked at the revs and it was just showing 7k rpm. Bloody hell... it really sends the car into an imbalance especially when the car is in mid corner. Oh well... time to have the fuel system looked at or getting the fuel pump upgraded. FARK!!!

BTW fuel starvation problem showed up with just 3/4 fuel in the gauge.

 

Hmmmmmm--- the more I read the more I think one could really get involved in a fuel delivery system.
Mazsports system is a really good system but I just dont have that amount laying around here at Christmas. And since I dont have FI that volumne of delivery and 1:1 regulator is not really required. It would be a bit overkill for me but for the FI guys its a great setup.
One thing about converting to a return type system is the likelyhood of throwing emissions based CEL's and I really don't want that but I may not have a choice if just a new pump doesnt solve the problem. By the way I won a new pump for $65 on e bay--gotta love it!
I have a freind working on a set up for me. We will see what turns out.
What I would like to have is like Dannobre's system with just a few more features.
that is a dual pump system--nonreturn---with impact/turnover safety features and a high speed only option(for track use only). The safety features may be available by taping into the stock fump pump wiring harness and upping the 15 amp fuse to a 20 or 25. I dont know for sure that is why I am letting an expert think about it.
WHo knows---if we can get a practical low cost kit available--maybe we can even market it?
olddragger

 

that is so funny.. i almost sent you a pm about that fuel pump.. wish i had now... i was going to buy it and offer it to you to experiment with.... ended up bidding it up more, but not very much...


beers

 

Mazports system isn't any more a return system than stock...from what I can see?? the stock system regulator dumps into the same position in the unit as the regulator in the upgrade. It has too to run the venturi. Thje big difference is the capacity of the pump...and the rising rate regulator when the car is in boost.

FYI OD..both pumps run on the stock wiring harness on mine...with the same fuse......never blown on me yet. both pumps will run at low speed...until the ECU says....go fast

 

I'd get one ASAP. Please do a kit with an easy to do DIY.