Couple Q's on tuning issues with alchy

[KevinB]

Kevin,
Shoot me an email with your address and lets try a different chip. Maybe this one has too much fuel for what you're trying to do. You could try backing the WOT fuel way down as a test to see the result (be careful, watch for knock).

Eric

Thanks! Will do when I get a chance. The last pass the o2's were at 777 but car would surge between 4500-5000 rpm (car went to 6K last night when it ran good and o2's were lower). Had the L8-1 setting at 126 today. Had the L8-2 setting at 120 or so trying to take the fuel out down low, also tried raising the timing to see if it would clear it up. In hind sight, I should have put 60's in this car instead of the 79's but I'm new to this alchy stuff lol. The goal is to get the car in the 10.5 range with room to grow for a future S2 or all out 109 build and hit the 9's with alchy.

Here's another thing I'm thinking....

I got 1.5 gallons of alchy from a friend's dad that runs an alcohol dragster.

Car ran bad from the start with this. Last night at the track the bottle was almost empty and we put in M1 VP meth. Car started to come around at the end of the night. Today the bottle was topped off with what I had left from the dragster....car ran like crap again. It may be a stretch but it has got me thinking. I know the alchy was good from the dragster b/c it came out of the same drum he got the fuel out of at the sametime and went to the track that night and ran mid-6's in the 1/4 mile.

 

[TURBO 6]

What position is the gain knob on?? The reason I ask is because I've gone as fast as 124mph @ 3750# with my gain knob on 5. Single nozzle, 25#'s of boost. 67mm P trim turbo also.

 

[KevinB]

What position is the gain knob on?? The reason I ask is because I've gone as fast as 124mph @ 3750# with my gain knob on 5. Single nozzle, 25#'s of boost. 67mm P trim turbo also.

5-6 has worked the best for me. I have tried every position.

 

[bison]

You need to get a wide band to get some actual data. Your beating your head in trying to read narrow O2 numbers. Too much time wasted. You need something that will data log and update 10x/sec. If your encountering a problem you will be able to eliminate variables a lot easier with a wide band. You should not be flooding with a single even at 8 if you have a chip that is anywhere near close. My advise would be to get the wideband and make a couple passes with 110+octane and no alky to see if the fuel in the chip is linear to rpm. Then add in the alky and turn it up a couple psi at a time. The last car i tuned with a dual nozzle was at 9.6:1 when i started tuning. It had no balls. Turning the boost up 3psi and pulling fuel out of the chip netted over 100hp with no adjustment to timing and all on pump gas. The POS Denso O2 never showed more than .810 even when the actual a/f was sub 10.0. Imo race gas out of a sealed can (even if its 94 unleaded) is the easiest to tune with because you know exactly what you are getting every time and the amount of oxygenate (if any) will be the same every time for the same type of race fuel. No BS pump variations. Garbage in and you have to leave a tuning window or you will hurt it. Quality in and you can run it at the edge and not fall off.

 

[jasjamz]

Thanks! Will do when I get a chance. The last pass the o2's were at 777 but car would surge between 4500-5000 rpm (car went to 6K last night when it ran good and o2's were lower). Had the L8-1 setting at 126 today. Had the L8-2 setting at 120 or so trying to take the fuel out down low, also tried raising the timing to see if it would clear it up. In hind sight, I should have put 60's in this car instead of the 79's but I'm new to this alchy stuff lol. The goal is to get the car in the 10.5 range with room to grow for a future S2 or all out 109 build and hit the 9's with alchy.

Here's another thing I'm thinking....

I got 1.5 gallons of alchy from a friend's dad that runs an alcohol dragster.

Car ran bad from the start with this. Last night at the track the bottle was almost empty and we put in M1 VP meth. Car started to come around at the end of the night. Today the bottle was topped off with what I had left from the dragster....car ran like crap again. It may be a stretch but it has got me thinking. I know the alchy was good from the dragster b/c it came out of the same drum he got the fuel out of at the sametime and went to the track that night and ran mid-6's in the 1/4 mile.

Use straight Meth out of a sealed can, set the gain to 6, and 20psi. Fresh plugs, oil and 93. I would even put in a new 02 sensor. I bet it will be fine. Now you can start your tuning process...again.

 

[TURBO 6]

I agree with Bison. You're chasing your tail with a narrow band. FWIW I was seeing .700 on my nb and my WB was reading 10.9:1.
It was a new O2 sensor too.

 

[quickt]

Hi Kevin,
Its obvious the car is too rich. (you need a wideband) You can try a couple things. Drop the fuel pressure so the engine run on more alky. I would try like 10 psi right off the bat. This is not a cure all but will let you know where you stand. Get another chip that has much less fueling and run the car on alky. I set the control knob as high as it will go and play with the fuel to get it right. They make good power this way. Never try to add more pump gas and take away the alky this just makes the stick of dynamite even larger.

 

[Bobs rare 6]

+2 on the wideband. My narrowband reads .770-.780 at 10.2-10.3 on wideband. Later, Bob.

 

[KevinB]

Well, did some more testing over the phone (car is back with the owner.) We turned the fuel pressure down from 42 to 38. The car runs very good now. It will pull to 6000 rpms no problem. It definitely needs a wb though. The car does not like 02's anywhere above 710.