ChevyNo1

Hey guys . . . I was initially running NGK TR6's @ .35, but the last plug change went to Autolite 103's. I had great success running a wet 150 shot previously with these plugs. Now, between 8-10psi with my new SMC alky kit, the car's stumbling at 4500rpm and up. I thought it may be the pump speed on the kit, so I took it all the way down to 2. Still stumbling. Dropped boost to 7psi, stumbling stops, whether the alky speed is at 2 or 6 ( which is halfway ). The guys at the dyno think it may be plug misfire. What are your thoughts on this?

I'm going to pull some plugs and check them out, because when we first started the pump speed was halfway; I think I may have fouled the plugs. Steve @ SMC wasn't sure about the nozzle size he sent, he said it may be too much. Maybe all I need is a smaller nozzle?

- Dug

Blackbird

103's should work just fine. what did you gap them too?

I am confused by your post. Are you saying with 7psi and water/alky it doesn't stumble but with 10psi and water/alky it does?

or is the 7 psi no stumble run without water/alky?

if it's the first meaning it's just more boost that screws things up then my first guess would be too big a gap and your blowing the spark out.

if it's the second, meaning no water/alky clears things up then try a smaller nozzle.

MIGHTYMOUSE

iTrader: (59)

what is your pe table like? my bad stumble was just too much fuel.. it didnt start until 4600 no matter what boost level though.

ChevyNo1

The plugs are at .035, which I've heard is the norm for FI. I got an email back from Steve @ SMC and he said he sent a nozzle that is too big ( miscommunication on how much boost I would run ). So he's going to send me a smaller nozzle, hopefully that should clear it up. It was kind of confusing as to whether it could be the plugs or the spray, but it sounds like a nozzle issue. I'll get the new nozzle and try it again . . . thanks for the help guys!

I don't think it's fuel, directly. Without the injection I'm at 12:0 all the way across. But with the pump on half, the A/F dropped down to 10. So it definitely was running too fat with the kit on. Speaking of which . . . do I have to pull fuel through LS1-Edit with the alky kit on? That would kinda suck . . . I'd have to have two tunes, one with the kit and one without. How is everyone else setting it up?

- Dug

Blackbird

yes you do need to adjust a/f with the water/alky flowing otherwise it will be on the rich side.

remember the alky acts as a high octane fuel.

Pro Stock John

iTrader: (34)

.035 gap with Autolite 103's is not the problem.

A 10:1 AF is way too rich, you are fouling out plugs.

I think that 11.5:1 - 12:1 AF for the street is pretty safe.

Blackbird

oh and as far as setting it up I run the alky 24x7 so I only have 1 tune.

NicD

iTrader: (7)

I think that's how we may have to set it up, unless with a smaller nozzle we can get the A/F to only go down to ~11.5. That shouldn't be rich enough to make it stumble on higher boost... I would hope. Then you would only need one program and the A/F would just drop from 12.0 to 11.5 with the boost up and alky spraying. That would be nice. We will have to play with it.

ChevyNo1

Sorry . . . I meant to say it drops to 11, not to 10 . . . but still too rich. Heath, that's kinda what I was thinking . . . I may have to have 1 tune and run it all the time. That's fun though, right??

Nic, I'm thinking I may just have to run it with 9-10 psi all the time . . . DAMN!!

- Dug

ChevyNo1

Heath . . . what size canister did you get? I opted for the 1-gallon and put it in the trunk. How long does it last in everyday driving? Of course, it depends on whether you lean on the car as much as I do

- Dug

Blackbird

I did a 5 gallon fuel cell out back.
It actually lasts longer than I thought.
But like you say it depends on how much you get on the car. But I would say if it's a daily driver you will get about a month out of a gallon unless your really on it all the time. I would suggest for cheap insurance get a low level sensor so it can trigger a dummy light when you get close to empty on the water/alky.

ChevyNo1

Actually the SMC kit has a low-level sensor built into it . Once it's at 1/3 the light comes on. Gotta like that!!

Steve @ SMC told me that I can lean out fuel pressure or add more boost to compensate for it running more rich with the alky flowing . . . correct me if I'm wrong, but if I add more boost, won't the MAF see the air and add more fuel anyway??

- Dug