MAximum rpms?

[seeker1056]

Hi all

Gettin ready to build a new pump for pullin next year and I wish to know from those in the know, what needs to be done to get 4000 rpm out of my pump.
Yes I understand that the fuel falls off at that rpm but I need the rpm in first gear before the governor kicks in so I can stretch out the 1/2 shift at half track.

I have read about clipping the spring and or shortening it but that doesnt sound like a mod with longevity as clipped springs tend to break in my experience in other applications. Not to mention it would be a serious trial and error thing to find the right stretch or shortness to get the preferred rpm.

is there a particular spring(s) from another application that will work?

Also would one be able to put a spring that would say, go to 4500 rpm or so, so one can "drive" the pump instead of just holding the fuel feed on the floor?

I beleive both KTA and Greenleaf and maybe one or two others already have a working solution?

Care to share please - even if it must be by PM?

Better yet, would one of you sell me a modified spring(s) that works for you?

thanx
Ken

[KTA]

I use the standard 3200 spring, but with a diffrent throttle shaft lever that is longer. That allows standard governing and driving with just a bit more sensitivity to throttle movement. I can tell a diffrence driving other trucks, but its not bothersome.

[seeker1056]

will this lever allow driving the pump or just pedal to the metal

Is this lever something you could sell me?

thanx

[KTA]

As I have said it drives the pump fine. I can't sell you one as I only have the one in my pump. I do not know the application it came out of. I got it in a box of pump parts I bought at a auction. If you have a big diesel injection shop close by I would just go and see if they would let you look through their stock of levers and find the one with the longest throw. Alternatively you could probaably grind off th high idle stop and modify your linkage to get some more degrees of travel out of your throttle. My pump is indexed to idle with the idle screw only in like 2 turns so I can get the most out of it.

[seeker1056]

my pump doesnt even have the idle screw anymore - I used the fuel screw to adjust the idle = almost bottomed out it is at 760 rpm hot idle in gear
Sounds like I will try to make my own lever longer as there are no shops around here for that kinda stuff

Anybody else with other ways of makin 4000 rpm? so i have choices?

as usual, thanx KTA for your help

[bgilbert]

I've never pulled a VE truck or VP truck. My theory is that you might be able to turn 4k rpm, but once a load is on the motor (sled behind you), it will pull down to the governed or max fueled rpm, which I would guess would be about 3k rpm. Dependant on where your max fuel point is, which I guess would be dependant on your setup (fuel, air, timing). My last trip to the dyno, with a poorly tuned truck, I made max power at 3k rpm. I'm pretty sure KTA has made 400+hp around the 4k rpm range. I'd have to dig out a dyno sheet, but I seem to recall making around 350hp at 4k rpm at one time.

Of course this might not have anything to do with sled pulling. I've just seen many stockish p-pump trucks, common rails and VP trucks pulling and just didn't have the ability to hold high rpm's down the track. My guess is the VE would act the same.

Maybe this isn't common knowledge, but a stock truck will turn 4k rpm with no load with the proper amount of throttle travel.

I think it will be hard to get any ideas on pulling 4k rpm down the track with a VE pump motor. My guess would be KTA will be the only one that can offer any advise or knowledge on the subject.

Or maybe stillsmokin and pulltilbroke can comment, I believe they are still pulling with VE pumps.

[KTA]

The white 1 gen in this vid is a 14mm, pod, hx40 truck with a dual disk clutch. H does decent with it for what it is. Its a daily driver and needs some tuning but most of all diffrent axle gears. There is no decent final he can run to get the rpms where they need to be to make power.

oops I just noticed I forgot the link to the vid!!
http://www.youtube.com/watch?v=9430zzr3fEc

[seeker1056]

to my knowledge - around here even in the Promod class with twins and all the bells n whistles - I am told they can turn 5000+ for about fifty feet then settle in around 38-4500 rpm dependin on the truck and track

Yes i know that 28-3200 is the ideal - I was just hoping to be able to run out first gear a little longer

Under power last year I was runnin around 3000 or so down the track in first gear, and slightly less in second gear

However if this isnt an option then i will design forr 32-3400 rpm and gear/tire accordingly

In any event I am looking for more rpm or power with the single as we have enough sponsors to run the whole curcuit this year

Ideas anyone?

[KTA]

The best thing I know to tell you to do would be to get on a dyno and see where you are making your power and what the curve looks like. Then you will know how to gear it to take advantage of the power. Ideally you will want it geared so that it runs no more than 500rpm over your peak power in the middle of the track on a running style sled.

[pulltilbroke]

This is stillsmokins truck pullin last year it was a 12mm,pod's,stgIV 4200

http://www.youtube.com/watch?v=-e6g2_BzKz8

If you notice the sled doesn't pull his truck down

If i'm wrong about his setup I'm sure he'll chime in


This is my truck with the same setup except with a 3200 spring and a lot less clutch

http://www.youtube.com/watch?v=DeLIMloOpJM

[seeker1056]

nice pulls

4200? as in rpm - how please

[pulltilbroke]

Yeah his 4000 rpm tach was buried on that hook i'm not sure if he's runnin a 4200 or a 3200 spring

I'll be runnin a 4200 next season in my new pump well see how it works

[KTA]

I am curious as to what sorts of finals you all are pulling? The few times I have hooked the trailer puller I run 1st high 3.54, which is 19.57 final. Back in the mid 90's when we actually pulled some highly modded 1gens we would run 3rd low 3.54 which is 11.58 final. That was really too much gear to work well. A 4.10 truck running 3rd low would be pretty close to right I think with a 13.42 final. So what do you all run?

[seeker1056]

we are runnin a 3:50 gear and in low range thats perfect for the 33" tires and the automatic as it lets us shift 1/2 and on some trax 1/2/3/2/1
We do NOT lose power on the track, just spin out and thats why we need more speed - to get the momentum up so we dont spin out on the smaller tire
35's are too tall to allow for shifting and stil stay in the power band

So where do you get a 4200 spring - never heard of one??

[pulltilbroke]

I'm usually running 2nd low with 3.54 and 285s which is a 21 or 22-1 final that is with a nv4500


I'll be running 1st high side at the next pull with 33" Interco STS's