1/4 mile vs. rwhp

[RGT]

I went to street night at New England Dragway I was the sole torch barer for the Cummins mark... . ran 3 times about the same16. 936 sec @ 73. 89, 17. 077@ 75. 60, and 16. 928 @ 75. 79, which I feel isn't too bad for a 6klb brick with 275k miles on it. The problem I had was that I was defueling in 3rd, thus the consistent trap speed, and not able to get overdrive without stepping of the accelerator, I guess I'll have to put a parralel switch to the overdrive solenoid so that I can manually engage it when I get over 70 mph... . in normal highway driving I can it will stay in overdrive for some pretty hard runs from45mph on up... I was a little surprised when it wouldn't shift up and defueled as I had quite a bit of track left... . the run profiles were as follows: 60'-2. 361s, 330'-6. 798, 1/8m-10. 619@63. 98mph, 1000'-13. 973s, 1/4m-16936@73. 89, my foot was of the pedal trying to get it to shift on this run... any one know what hp this would correspond to? The only other diesel was a new GM 3500 4x4 quad cab that ran 14. 8s, he said he had a 100 hp box on it, only other truck of note was a little Ford lightening that was running in the high 12's... there that said he had a newer Dodge, diesel,4x4 that ran 19's before he added some sort of box and 17's after... ... I was pretty impressed with how many sub 13s street cars there are out there... .

 

[drives mopars]

my 93

i run 15 at 92 with 400 at the ground and 950 torque



was at 17 at 82 once



its still going strong my 93 4x4 dually







we need to have a sacramento meet in the spring 04



ill help plan it sac race way



bill

 

[paccool]

Yours did just about exactly what mine did. I also had trouble shifting into OD sand the truck just sorta floated the last 400 feet or so. You can't tell much about the power but it sounds like you have about what I had at that time. I was around 190 at the rear wheels.



I need to take it over again since the new PDR HX35 turbo install and the Piers tuneup. Now have 270HP and 620 on the torque and it will shift into OD. Try turning the 10mil square drive under the TPS counterclockwise a little and see if this helps the OD problem. Nascar Mark had to turn mine back 3 or 4 times before it was right. Or you can try the voltage type adjustment that Bushwacker has posted.

 

[BushWakr - RIP]

Try sliding your throttle valve cable back about 1/16" and increasing your TPS voltage by . 25vdc



See if that helps you get out of 3rd, into OD while holding the accelerator to the boards...



bob.

 

[dzlpwr]

I had the same exact problem... No overdrive with foot to the floor. I am going to put a switch in parrallel and switch it manually. About what speed does your transmission shift into OD while running the quarter? So far without any OD i am running a 16. 142 @ 74. 78 mph 1/4 and 9. 018 @ 67. 143 1/8.

 

[RGT]

Paccool I wrote 180 hp on the tech sheet prior to running, so sounds like I am in that ballpark... Bush, increasing the output of the TPS sounds counter to what I was thinking, I was thinking it would shift into overdrive at a lower tps voltage???? what does sliding the throttle cable back do?(pull harder on the high idle stop?) I was not able to get it to shift into overdrive during the run..... (at least not before going through the trap, and only after taking my foot off of the go pedal... .

 

[nascar mark]

RGT,



You are correct. Lower your voltage will help with a hanging up O. D.



Bob's too excited about going hunting!!



I'm with Dzlpwr as for needing a manual switch for O. D. when full throttle. Sometimes it will go in but more times not.



I ran a 14. 70 two weeks ago in the 1/4 at the track with no O. D. because unless I let off and wait a couple of seconds it won't shift to O. D. Ran a 14. 86 @ 90 mph last summer with O. D. and 70hp less hp than I have now with a hx35.

 

[RGT]

did a quick search and it looks like some people have put in manual switches on the overdrive, looking in the Powertrain Diagnostic Procedures manual I can see where splicing into the Org/LG wire to the trans and grounding it will give me overdrive when grounded reguardless of PCM and will work normal when the wire is ungrounded... I see that there will be a fault condition generated by the PCM, will this result in my check engine light being on? and will it clear itself when I turn the switch off?

Mark, thanks for clarification on TPS setting. .

 

[BushWakr - RIP]

Yup my mistake, sorry about that... . you'd think after all the times I've posted on the TPS I wouldn't make that simple error... .



What I'm suggesting is trying to get thru the first 3 gear a bit quicker and into OD a bit sooner.



bob.

 

[RGT]

when I put the TPS back on after doing the throttle shaft I set it just about as low as it could go without it bottoming out and preventing the throttle lever from resting on the low idle stop, I don't think I could get any more lower in my setting, I have not put a meter on it as I love the way it shifts and drives normally... Bush, what would the throttle cable adjustment buy me?, I would like to get the overdrive in by 70 mph on the track, maybe even 65 and see how my et/top speed fare. Thanks for the input

 

[soslow91]

Well since I don't think the tdr is the place tp meet hot chicks I'm not real worried about being labeled a nerd in here so I'll go ahead and post the formulas I have but don't seem to remember the source of.





3rd root of weight/horsepower x 5. 825 = elapsed time



so if you already know how fast you went and what you weigh



weight/ (ET/5. 825 cubed) =hp



This would put the weight of nascar marks rig at just under 6000 pounds so unless its really that light it either makes more power than the dyno says or the formula favors diesels a little it seems fairly accurate and sometimes embarrasing for most of the gassers I've punched in.



using mph



hp/weight cubed x 234 = mph



This puts Marks hp closer to 340 @6000 pounds simply meaning he needs to be in overdrive for the numbers to match better

(I have a toggle switch on mine merely because a new tps and a new speed sensor didn't fix the overdrive or the cruise so I suspect the computer and havent found/don't want to buy one)

 

[RGT]

so if i've done the math right, and this thing weighs 6k lbs, I am more like 240hp?