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Dyno & Track Times

A

Avalancher

GUEST
OK,

I've modded out the engine about as far as I want to go for a while, and I want to know what I've got. I've never dynoed or timed anything, and I want to check it before I put on the 33's (I don't plan on doing gears in the near future so they will probably hurt my time).

Can anyone give me some advice in pursueing these? Are there dyno types? Different track types or timing methods? Are there better ways of recording good results? What kind of costs should I expect?

TIA
 
Avalancher, nothing beats the 1/4 mile for knowing what it was all worth IMHO - but you should get a dyno, surprised Ed Wright didn't do a before/after for you.

There should be some shops in your area that have a standard dyno - plan on at least two runs - about $75.

Good luck and report your winnings >:D
 
The strip is much more fun than the dyno but not as exact. You will need a helmet for the strip. Most places with a dyno can also check your exhaust to check for fuel mixture problems. Strip should cost around $20 for time runs (you can fit in 10 or so on a slow Saturday). I used to work for Sun Electric / Snap-On, and a friend has a '69 Z-28 with a 600+ CI BB (super street 9.90 and then some, was able to do 9.20s). I had both my '69 Mach 1 and bike to the strip as well. The reason you did all of the mods is to go fast and its legal at the strip!
 
According to my set of NHRA rules you don't need a helmet until you break 14 seconds - how is that for a challenge.

Short version NHRA rules ;D

Try it, its fun, and watch out for the clunker trucks, they are the sleepers.
 
So what's my best bet for fastest time?

1) Tow/haul on vs. tow/haul off
2) hold down the brakes and have gas pedal to the floor then let off vs. let off brake and tromp it?
3) 4 Hi vs. 2 Hi
4) Drive, 3rd, or manually upshift
5) AC off, (windows up?)
5) How warmed up should the engine be?
6) ??? Any other tricks you guys have...

It sounds like I need to find a cool, low humidity day. I assume this applies to dyno runs as well. Are there any techniques for dynoing?
 
G-xx will be the better man to answer these definitively, but since I'm here now... :)

Tow/haul : On, but I think at full throttle this doesn't make any difference.

Powerbrake launch: ?not enough slippage (stall speed) in the stock converter to make much difference here... two footed might help your reaction time however ;)

Never having raced a 4X4 before, don't know the answer to the 2hi vs 4 hi question... I would hesitate to run my T-case locked up on pavement...even for just a 1/4 mile though. hmmm, further thought... unless you're having serious traction issues, it probably does more harm to waste power turning the front drive componants than the good you get from the traction...

AC: off. ?Windows: ?Ideally they should be up (less aero drag) but with something with the aerodynamics like the Av, I'm not sure it matters much. ;)

manual shifting vs. auto: ?if you're doing heads up, try manual and run up the rpm a bit higher than the stock shift point... if you're bracket racing, let the tranny do it's thing... still pretty quick and VERY consistant.


Ideally you want cold air coming into the engine, but the engine itself has to be up to a minimum operating temp or you'll not get the full hp out of it.

Again, Gandolphxx and butch are far better equipped to address this particular vehicle, but the above advice is offered at face value :)
 
I have not heard of Ed Wright

Can someone give me some insight into what he does and the cost?
 
Avalancher said:
So what's my best bet for fastest time?
Click to expand...

1) Tow/haul on vs. tow/haul off

Tow/haul will hurt your 1/4 mile times - tested and rejected.

2) hold down the brakes and have gas pedal to the floor then let off vs. let off brake and tromp it?

Hold the brake and rev to stall and go is a workable strategy - tricky to do - a line lock would be a better bet.

3) 4 Hi vs. 2 Hi

2HI will work best if you can hook up, if not use AutoTrac.

4HI only applicable if you have nitrous above 100 shot and really believe that your transmission/differential can take it.

4) Drive, 3rd, or manually upshift

Drive works fine, depends where you end on the first few runs and the shift points you have selected - with the Transgo you can use 3rd and it will lock out OD if you have the performance kit version - may or may not be your best solution.

I wouldn't recommend or attempt manual hsifting with the steering mount that we have, real easy to do something stupid.

5) AC off, (windows up?)

A/C has to be off and windows up by track rules - cant have anything dripping - besides, you wouldn't want to lose the power.

5) How warmed up should the engine be?

Not stone cold, after that keep it as cool as you can, thats why you will see folks with the hood up, pushing their ride to the initial staging area. You have to drive it to the line. That, btw, is not an option with your truck.

6) ??? Any other tricks you guys have...

read Jeff Tyler's Drag Racing Basics and check the rules of your local track.

Avalancher said:
It sounds like I need to find a cool, low humidity day. ?I assume this applies to dyno runs as well. ?Are there any techniques for dynoing?
Click to expand...

Make sure they know you have TQM removed, otherwise they will dyno it in 2nd.

Hope that helps ;D

One last though - race on the outside of the track, gives you more room to stop before exiting - coast down and save your brakes, let the other guy get off first, then you know where he is.

Last, last piece of advice, race yourself, not the guy in the other lane - he has enough to worry about - and watch out for him - remember it is supposed to be fun - don't push it the first couple of runs, get used to the track and environment.

NB; better do this before the 33" tires, cause your not going to like the times with the 3.73 afterwards.
 
Here's what worked best for Me Avalancher.., or trucks are similar, except for My 4.10 gears..., and Modified Trans, with a Lower First Gear...., My best runs where in Auto-Track..... Rev limit on the HPP3 set to 6100 r.p.m...., Trans shifted at 6000 on the 1-2 shift, and 5900 on the 3-4.., but I was already in the Traps when the 3-4 shift came in......... I brake Torqued it off the line, Stall was almost 2800 r.p.m....... I ran the B.F.G A/Ts at 30 lbs pressure in the rear, and 75 lbs in the front for more Roll Out.., and less rolling resistance..., truck was hooking up Very Well..., had 60ft times in the 2.0s......... I removed the spare tire, jack, and bed mat to save some weight......... I used Ice packs on the...... intake manifold between runs, and keep the hood cracked to let heat out...., Your Electric Fans will work well for cooling between runs..., I assume you wired in the Manual Over Ride switch to run the Fans while the engine is off...., and to Manually shut the Fans off....., if so run the Fans till you get to the line..., once your about to Stage..., Shut them Off...., You wount need them during the run, and the alternator wont be working to power them...., just remember to turn them back on after the run.......... Most importantly...., Just Have Fun ;D
 
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