Engine/Transmission (1994 - 1998) P7100 Tuning help

[SEmerson]

I am still on a quest for less smoke. I have a very small boost leak in the horn. All others are fixed. I added a 24v inter cooler. My #6 is back all the way. Afc houseing is back all the way. I have the heaveist sping in the PDR afc kit. Star wheel is turned back 3/4. I still could hide a car with preboost smoke. But topend is ok. medeam black once spooled. Boost is down to 36. Trap speed is down 2mph. What can I do to still kill preboost smoke? Shouldn't the starwheel work to kill it all?



Also What would be the next step? A valea switch?



What about turbo in a bottle?

I know nos would work good but what about water meth or propane for the top end cleanup?

 

[Sled Puller]

Are you sure you have everything cranked the right way?

 

[SEmerson]

I just unhooked the afc pressure line. I can still make a lot of prespool smoke. I some how need to make the afc arm start back farther. And probly add a valet switch.

 

[mikel]

A valet switch only prevents boost from getting to the AFC and moving the arm. If you're having a problem with pre-boost smoke then I don't think a valet switch will help you.



I'd bet the 191's and 370's are just going to make smoke. Maybe step back from either one or both of those to the next smaller size and see what happens.



Did you adjust the pre-boost screw on the back of the AFC? Back it all the way out to try and kill pre-boost smoke.



Good luck,

Mike

 

[Cooker]

With the valet swich, my truck smokes very little off the line. Apparently this did not help your problem much and I wouldn't have imagine it would given your setup. 191 D-Valves are the culprits. If you remove them I guarantee your off the line smoke will be greatly reduced. The question is, do you really want to remove them

 

[SEmerson]

191 have to stay. My 370 were starving before them giving me a miss.

 

[HoleshotHolset]

My '94 misses like crazy with the 131 DV's in it along with the 370's. :-laf



"Cut" and "022" DV's smoothed it right out...



Pre-boost smoke? Oh yeah.



Matt

 

[Cooker]

Originally posted by SEmerson

191 have to stay. My 370 were starving before them giving me a miss.

It is crazy how different some pumps/trucks are even though they are the same "model" I also have a 180 pump timed at 16 degrees and I do not have any miss or stumble with my 370's and stock 181 delivery valves.

 

[1dslram]

Steve:



As you has been said before with the 191's and 370's there is no way you will even get the preboost smoke to a medium black. Pull the 191's put in 181's and adjust the AFC properly and you will cut your smoke in half. The 191 DV's are not a cure for an improperly set up pump.

Bruce

 

[SEmerson]

I know I could make my truck smoke free if I removed my 191's and or my 370's. That is not what I am looking for. I want to stay at a high power level but not over fuel. I am trying to get my fuel to match my air as close as posible. As far as my 191's being a fix for a mis tuned pump I looked for a fix to my miss of a long time. The only good aswer I got was my DV's were too small. I changed them and it runs great. I would love to know how to better tune my pump. That is what this whole thead is about. If I have some smoke that is fine. I am just looking to be as clean as posible for my power level. I was hopeing the HX 40 would have done better. But for now this is what I have to work with.

 

[BPonci]

You can get your smoke down with a staged afc control. I can get mine down with l/c and 370s.

 

[K5IP]

SEmerson,

I too have a smoke problem with a #6 tst plate (95 5spd). So much so that I have removed the plate. I thought the upper end performance was great but, like you the pre spool smoke was enough to kill every misquetoe within a mile. I just will not put up with smoke like that. (the smoke image is killing our diesels with legislation).

Keep us informed if you resolve this. Given an acceptable answer, I would try my #6 plate again.

Rog

 

[Andy Redmond]

Remove the pump and take it too a good pump shop and have it calibrated. For a bit more they'll likely do before and afters on the pump stand with and without the performance parts and likely make some other adjustments to get you the best of both worlds, with your goodies.



The HX40 is known for some lag.



For a short term fix have you backed off the pre-boost fueling screw, then run it in until it just touches the link? You might have to screw it in a bit.



Another trick is to back off the afc housing on the bolts, start sliding the housing back from full forward 10-20 thous at a time and richen the star wheel a bit as necessary.





Let us know what you find out. .

Andy

 

[SEmerson]

I have added more top-end fuel now. Power was down too much. I found that my pre boost fuel setting was turned in a little. I fixed that. I now have very little light to medium throttle smoke. I am much happier. I will add a valet switch soon. I am getting much closer.