94-97 tuning thread.

Derek@Vision Diesel

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I can start it off, obviously i had a reason to make this thread.

How come some tuners still say on their webpage that 94-97 trucks need a boost fooler above 36 psi? Is that really true, ive never even thought of having one because most say its "tuned out" or not needed with custom tunes.

Also what in the tuning deals with WOT shifting, seems as though my truck shifts awesome until i go WOT and then im bouncing off limiters and getting real crappy shifts.
 

Tom S

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OK, I will toss out one. How about chip not having the same MPH shift points from one PCM to another in the same truck. My OEM PCM has shift points that are 3 or more MPH higher then if you put in another PCM of the same code.
 

psdguy95

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Subscribed. My dp tunes have the " no codes" for the boost issue. I thought the boost issues were above 26 psi?
 

wint

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Got one for ya'll. Just got my beans tune back and when under wot at a higher speed and rpm, the truck defuels massively. It slows the truck hard enough to throw me forward. Some may say its the HPOP but there is no way, not unless it would completely fail then come to.
 

Estrogen Hostage

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Got one for ya'll. Just got my beans tune back and when under wot at a higher speed and rpm, the truck defuels massively. It slows the truck hard enough to throw me forward. Some may say its the HPOP but there is no way, not unless it would completely fail then come to.


What about your fuel filter?
 

Estrogen Hostage

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I would like to know about throttle sensivity. I had a tw tune a while back and it was on a stock truck with stock injectors, so it didn't add a whole lot of horsepower, maybe 20% tops.

Anyway, my throttle became very sensitive with the tune. It wasn't a huge deal on the road, but driving through the pasture I had a hard time controlling the throttle becuase of it. I'd like to know if tuners make the throttle response non-linear to pedal input to make the truck feel more powerful than it really is.
 

JD3020

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I would like to know about throttle sensivity. I had a tw tune a while back and it was on a stock truck with stock injectors, so it didn't add a whole lot of horsepower, maybe 20% tops.

Anyway, my throttle became very sensitive with the tune. It wasn't a huge deal on the road, but driving through the pasture I had a hard time controlling the throttle becuase of it. I'd like to know if tuners make the throttle response non-linear to pedal input to make the truck feel more powerful than it really is.

I think some have the fueling come on at lower throttle inputs like you said. I know that when my brother had his old OBS with TW tunes it was very touchy and was a pain to drive. Then i got Matt's tunes on my truck and its not even similar. The fuel/power comes on a little quicker than stock but its not even noticeable, and that is only in the hottest 2 tunes.

And thats why i like Matt's tune. My truck has literally never left the race tune, except for one time towing up a steep hill i bumped it down to tow because i have exhaust leaks and my turbo is laggy and i was getting under the turbo. It drives just like a stock truck unless i get on it.
 

Derek@Vision Diesel

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We need someone in here that actually tunes haha... Lots of questions, lets answer them from the top down if someone is willing to chime in!
 

Tom S

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Also what in the tuning deals with WOT shifting, seems as though my truck shifts awesome until i go WOT and then im bouncing off limiters and getting real crappy shifts.

It is interesting you bring this up. I helped Jody (read driver) work on some fresh tuning for the OBS trucks last year. We used a very low mileage OBS truck that was in great shape and really worked on the shifting. We also spent a bunch of time creating tunes designed for mountain driving where the upshift/downshift points are closer. After a couple of days of work I thought it was really dialed in. I have other friends that run those tunes and they really like them and Jody has lots of customers that do as well.

I tried those tunes in my truck and guess what? It will not shift at WOT and hits the rev limiter. All of the shift points are off by a bit like 3mph higher. We had come across this before where my truck does not shift at the comanded MPH like trucks normally do. I was wondering what was going on here and if it had to do with my BTS.

We tried an experiment and I put one of my spare PCMs in the truck. Magically now those tunes that would not shift at WOT now work just fine. Something in my PCM has a small effect to the shifting to where it does not exactly do what the programming on the chip commands. I am not sure if it is some kind of firmware in the PCM not addressed with a PCM base code or what. My stock PCM is a NAW4 that has been reflashed to a TDE1 code. The test PCM I used was from a 97 truck and was a NAW6 code.

Jody was able to address the issue with pretty quickly by lowering the shift points the proper and amount and then driving it a bit but it was really interesting that this happened. I think he said he has only had a couple of cases where this occurred. Maybe your truck is like mine and is the oddball one. It would be easy to blame the tuner if you ordered a chip and this happened but the real issue is with the truck/PCM not acting like the normal. If you have a spare PCM you might want to try this just to see.

Tom
 

morefuel

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I have problems on the 100 hp race tune on my 7.3. It becomes very hard to get my revs matched right for a shift. Also when I go from full throttle to about 1/2 throttle at higher rpms the motor basically drops all fuel and then surges back on to where it should be. But I'm kinda thinking that would by my hpop not keeping up.
 

kip4234

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Tom could it be that one of the computers has been programed before chips were out on these trucks. I have owned my truck since new 1996 my first burn was done directly to the computer non chip. I still have it Hypermax did it and I took it out and put a stock one in that I use for my DP-tuner???
 

Tom S

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Tom could it be that one of the computers has been programed before chips were out on these trucks. I have owned my truck since new 1996 my first burn was done directly to the computer non chip. I still have it Hypermax did it and I took it out and put a stock one in that I use for my DP-tuner???

I do not think so as I have had it reflashed to TDE1 code and all the rest of it works fine. The truck was 100% stock when I bought it. It is just this MPH issue that messes with the shift points and in turn makes the pressures off a bit. Nice to see you post here by the way!!!!
 

black974door

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o got one, i used the same tuner with both sets of injectors. i fist had the problem with stage1's at the track. pre-stage rev to 15-1800rpm roll into stage, and wait for the other guy. by the time i left the light it acted as if i was spinning the tire but it made no noise, no smoke, and i know it was lock in 4wd. turn around at the end of the track and noticed the tc locked in first gear at 5mph and wouldnt unlock between shifts like it normally would do from 2-3 and 3-4. took the chip out to get ruburned for the new injectors and went back to the track. 18-20 runs and not one problem out of it. through the new injectors and chip in go down a back road and try it out. same problem. switched chips with my buddy and it acts like a completly diferent animal
 

woodduck97

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BTW me and Black974door are running almost idenical setups. We both have switched chips back and forth.

After this thread the computer coding I think maybe having something to do with the way my truck idles and drives. At idle my truck shakes pretty good and while driving under light throttle mine will buck. My code is TDE1. His on the other hand drives much smoother and idles better. Once I get the BTS in the next week after it ships we will have to try swaping out computers to see if that fixes my problem or betters it. Matt and I have tried to better the problem and seems about the same but has gotten a little better. Sounds like now it could just be the computer coding was the problem all along.
 

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