The other day I called JDM and asked a question about my chip because I was thinking of upping my boost a bit. I forget who I spoke to but, he had me read the code on the back of my chip and he looked it up(CXN1-39J7-E2F). After a couple mins he came back and said I could actually install my 6# lower pulley in place of the 2# pulley thats on it without a reburn because my tune is a generic tune for either 2, 4 or 6#s of boost over stock, as long as I got a good set of plugs in the truck such as TR6s. My question is, is this all true ? Can I really run my 6# without a reburn ? I may have mis-heard him or he could of made a mistake so I'm in no way trying to start any trouble, but I would like to know if this is all true. If it is I think I may be installing the pulley tomorrow LoL. Thanks to anyone with any input on this. Also those with nothing to say without bashing someone please dont respond at all. Thank you



Josh

 

Josh

If this is the chip I am thinking it is, it may not actually be what it says on the chip. I will get a hold of Jamie tomorow and ask him.

I think Jim reburded the chip for him at Epping last year, and may not have relabled the chip for him.

I know that is a good strong program, and the truck runs real strong with it.

 

yeah don thats just it. I wasnt sure if Jamie ever dynotuned the truck or custom burned the chip without relableing or anything. I'd like to step it up to my 6# pulley for a lil more power, but I'm not sure if I am gonna have the money for a new chip.

Though I guess if it comes down to goin faster or gettin rims I'd rather go faster. lol.

Thanks Don


Josh

 

what chip are you running in your truck now??

Are you running the JDM or a different chip??

I know Jamie ran pretty dam fast with that chip and the 2# lower.

 

trucks the exact way I got it delivered right now. Same Chip/pulley/intake and everything. It definetly has run fast 12.72 w/ 1.9 60' on only the 2#, but I'd like to dial it up a lil bit...I got a friend with a Mach 1 and some work that is tough...I wanna surprise him LoL


Josh

 

Josh, one of the best-kept trade secrets is,
sometimes there really isn't a diff,
strange but true

Ok everyone, Bring it on

AT WOT a chip has the computer go to a pre-determined fuel chart (map). EXACTLY how much air comes in, and EXACTLY how much fuel you have to add, has always been the balancing act on which our A/F lives, and it's also what separates the great tuners from the ok tuners, obviously JDM are in the great category, (along with most or all of our vendors/tuners). That chart or Map IS NOT as diff as people think it is when your comparing 2 to 4, or 4 to 6 lb pulleys. The main thing a tuner shoots for (and it takes time and experience), is a tune that works well with all L's, and of course a safe A/F across the board. So since your already tuned for a filter chip n pulley, by adding more pulley your really only adding more boost and sometimes that doesn't warrant any change in the A/F, but of course most would want a looksy on the dyno to check or tweak it.

WOW I THINK I ALMOST MADE SENCE
OR SOMETHING

 

LMAO wow Rob....you just actually made alot of sense. I'm impressed. LoL.


Josh

 

as long as your not pegging you maf and your a/f was good to start with boost doesnt matter just so long as your MAF isnt maxed

 

I am running that same J39 program from JDM. Currently I have a 4 lb lower and a ported supercharger. Also, at times I see 15 lbs of boost. My last dyno run the a/f was 12.2 through the tail pipes. My LM-1 reads 11.7 a/f in the post cat o2 bung.

Funny thing is, this is the same chip JDM burned for my stock engine.

Sometime in early Sept I am going to get a dyno tune from Sal. I'm anxious to see how much more hp/tq that I can get from a custom tune.

 

JDM did reprogram that chip, but he did it in his shop and it is labeled correctly. That program is not the most aggressive, but it works well under all conditions. It has a great street program (side 1) and a very consistent race program (side 2). If JDM says it will work with more boost, I would believe him! I have one program for my truck now and I vary the boost from 15 to 20+!!

 

If you aren't pegging your MAF, you won't have any problems no matter how much boost you run(as long as your fuel system is also put to the task). The MAF reads how much air is being pulled through the meter and the pcm dumps fuel accordingly. If your MAF is being pegged, there are a few ways around it. Most Lightning tuners are richening the mixture at the last portion of rpm before the meter is pegged. The other way is to scale the meter so it doesn't peg. Either way will work and you will have plenty of fuel.

You really need to deal with your vendor because they are ultimately responsible for the tune.

 

Interesting factoid.

Let me offer a possible explanation. Air-fuel is the amount of fuel in relation to the number of oxygen molecules (not "air"), right? The Heaton is overspun from the factory and is already at the outer limits of its efficient range.

So, as is demonstrated by the incredibly poor HP-per-PSIG increases from 4, 6, or 8 lb pullies, spinning the SC harder does not produce that many more oxygen molecules coming out of the SC. Why? Because the air is being so severely heated that its density is declining rapidly per pound of additional boost. You are moving more air, but heating it up more at the same time (as well as increased mechanical effort to pump it).

So, if you had a chip tuned for 4 PSIG (stock - 4 PSIG), it might not work well in an 8 PSIG application. But a chip tuned for 10 PSIG (stock +2) will usually work okay with 12 or 14 PSIG (stock +4 or 6) because you are not getting anywhere near the increase in air density (i.e., number of oxygen molecules) that straight line math would suggest. So, because going from a 4lb pulley to a 6 lb pulley does not require the addition of much more fuel because you are not moving much more oxygen through the system.

I suspect that this is not true when going from +2 PSIG on a KB to +6 PISG, as the KB is still in its efficient range, and would be providing enough extra density to lean the mixture out too much.

Comments?

 

Thanks for your input Jamie. You afterall know more about this truck than just about anyone. So your tune on this chip isnt an aggressive 2# only or specific dynotune reburn ? I just wanna make sure I dont blow up my motor.

Your right about this truck being consistent...I couldnt believe how many times in a row even when hot lapping I came in within .1 of the previous runs. But I would like to have a bit more power.


Josh

 

I've seen the basic Superchips database here locally and they have designated generic tunes for different sized pulleys.

I don't think any generic tune will cover such a large range of boost increases (2 - 6 lbs.?) unless it is pig rich with stock timing or something.

On another note, JDM's tunes have always been excellent. I've seen dyno sheets of their flip chip programs and the AF is always very flat and right around 11.5 - 11.7. I think most of their street tunes command a 14 or 15 degree max timing.

 

Yeah, Jamie was always chasing Jim down for the latest and greatest tune.

His truck ran very good on just a 2lb lower, till i had to whoop his ***. That's why he bought Gamino's truck. Just to put me in my place!!!!