OK....

My buddy changed projects mid-stream to pursue an f-body (who wouldn't?) and he had an Eledbrock Performer RPM kit for a Holley Dominator (big noids).

We got the fuel line to tie the fuel noid to the rail, and this is the distribution method used, a plate by "Slot Car Racing" seen here on eBay: http://cgi.ebay.com/ebaymotors/SALE-...spagenameZWDVW

The plate seller advises NX style jets, so we went with 52N/28F (100hp shot). The car has a brand new Racetronix pump and harness and colder plugs. Bottle heater was working and the bottle was at about 900psi. We have verified that fuel is fully functional at the point that it enters the plate, but at WOT it hits good for about 1 second and then the car shudders terribly. I tune his car, so he brought it up here and we went out and log, and Bank1 goes DEAD lean just before the shudder. We stepped up JUST the fuel jet to 35F (150hp fuel jet) and left the nitrous the same and logged the same result; this time with 2.2deg KR. Oh yeah, he is running 1/3 tank of race fuel right now also.

After the last test and seeing it keep leaning on bank1, I am beginning to think it's a distribution problem. The plate has no fogger extending, the "nozzle" is machined into the inside opposite the outer fitting and sprays from the side. What do you guys think?

 

That is a big problem, your N20 probably pushed fuel back up the lines.
Put the NX nozzle a few inches in front of the TB like everone else, and you will be fine.
Vinny

 

There IS NO nozzle, the point that they mix is in the side of that plate. There are like 8 holes that a "mixture" should be forced out of on the inside side of the plate.

I suppose the N2O pressure could be slowing the fuel in this setup as well.... this means that the plate is a defective design.

 

I mis-understood the first post. I though this was one of the other Slot-car plates that a nozzle screwed into. I know people have complained about that design, as far as distribution.
You are the first person I've heard of using this new plate.
Do you have a wet nozzle kicking around that your could try instead of the plate?

 

Frost I have a couple of nos wet nozzles and jets laying around you guys can try those.

 

Nice, thanks James... I'll call you tomorrow, about to go out to dinner with uhh..... well..... anyway...... yeah

 

I have had some problems with the edelbrock fuel noids before. It would hit hard then fall on it face(lean). Bought a new one and fixed the problem.

 

OK

So we still have this problem... I tried one of Z284U2TRY's NOS foggers, and the spray is looking nice with the fogger out of the car and the button held for 3-5 seconds.

Put the fogger back in, go down the road. At first it hits and all is well, and after about 2-3 seconds, both O2s go DEAD *** LEAN... as in 15-40mV lean and I tell him to let out. That's 15.0:1 or leaner guys!!

What do you guys think? I'm leaning towards faulty factory regulator, but it seems fine at all other times so.... This is a freak of a car too guys, it's a 2000 B4C with a good amount of miles on it and it went 12.55 @ 110.55 with just LTs/true duals, lid and tuning. Stock TC and all....

Thanks for any help or insight.

 

Without knowing what his Fuel Press. is doing, try this.. Bottle closed, and make a run with the "nitrous" on, the additional fuel should bog it down rapidly, making it fall on its face. Its much safer than you running 20:1 AFR troubleshooting. If the car bogs, you have a fuel issue, be it, noid, regulator, fuel filter, dirty intank pump sock, or something. But you wont be burning it up finding it. GL

 

Also, I would check the fuel feed hose from pump to tank top...never heard of a stock acordian line busting, but have had experience with the "high pressure" fuel line splitting.

 

We did this very early on... before my first post even ... It goes really rich as it should (mid to high 900s on the NB o2s), a few backfires out of the true duals afterward even. Just prior to the bottle (as in days before) the fuel pump (and sock obviously) and filter were replaced, as well as the stock pump harness. With just the fuel spraying it acts just as it should. I agree a FP guage would be nice, but we have to work with what's here for now.

I mentioned checking that same piece of line to him yesterday, maybe he will have some further info by this evening... Thanks

 

Bump for new info....

Have a nice autometer fuel pressure guage now, and OFF THE BOTTLE the pressure goes from about 60psi to about 57psi.... ON THE BOTTLE the fuel pressure is EXACTLY THE SAME but the car still gets so lean that the 02s switch!! This is with a fogger now instead of the plate. It only seems to leave the fuel noid, but with the fuel line out and the bottle off testing it at idle a steady stream of fuel comes out of the fuel line from the noid; no breaks in output.

I'm stumped.

 

Ditch that thing and get a single nozzle.

 

You know the the line between the fuel selonoid and the nozzle isn't clogged partially? You can try it without the nozzle for fuel/nitrous, and then with the nozzle fuel seperate and then nitrous seperate. Check the ground on the relay? That's all I got...and those are long shots...

Yeah seriously take it all out, check everything seperately and put it all back in and rewire it...single nozzle.

 

Read above, we ditched the plate for an NOS fogger a while ago...

Think we are onto something, will post back up in a bit

 

Got it..... At 58.5 psi DEAD NUTS under WOT, it turns out that every online list and calculator was just viciously lean for this setup... These are Edelbrock's big noids if that matters... 63N and we had to move all the way to 46F to get **** where it should be AFR wise, and we could stand to probably be just a step higher on the F side, I am cheating his PE table right now by about 2% to make up for things.