How Dose a dyno run work?

[SchoolBoy]

Since I am going with a friend of mine with his 89 GT to have it dyno'd, I have a few questions. Now I was wondering how exactly dose it work, start to finish? Do they have you actually pull gears, or do you just do the pull in one gear? Now they are going to do three pulls, so I guess that the first is a base line, and the next two are for ajustments, right? Is there anything I should look for when the guys are hooking the car up, and when they are running it, just to make sure they do it right?

[Mike Croke]

1. Drive the car onto the dyno roller.

2. Strap the car down so a tornado can't move it. Experienced dyno folks will strap it down, then have someone "drive" the car for a few seconds to allow the car to re-settle itself. Then the straps get cinched down again.

3. An inductive pickup similar to what's used with a timing light is attached to a plug wire so engine rpm can be measured.

4. If the dyno is equipped, a tube is inserted into an exhaust pipe to sample for the wide band oxygen sensor. This will allow fine tuning of the air/fuel ratio.

5. Start the car and "drive" it normally through the gears up to whichever gear is 1:1. Typically, all runs are made in 1:1 gear. Thus, 4th on 5-speeds and "D" on cars with a secretary's transmission. Runs can be made in other gears as well but the higher gear allows for a slower pull resulting in higher power numbers and more data sampling points for a smoother graph.

6. Once "cruising" at a constant 2000rpm in 4th, the dyno operator will press a button to start "recording" and the car is run at wide open throttle to max rpm.

7. At the end of the pull, take your foot off the gas and push in the clutch and coast down. Under no circumstances touch your brake pedal. The dyno is equipped with a stupidmonsterpowerful brake. If you hit your brakes and the dyno roller is trying to slow your wheels, there's a good chance something will break/bend on your car. The dyno will win.



That's it. You can make adjustments to the car and then make another pull until you're satisfied or run out of money.

If it's a Dynojet, usually they can print out a graph of your runs showing the power/torque curve, air fuel ratio, engine rpm, etc. Most modern places can email you the dyno files and you can view them using Dynojet's free viewer available from their website.

[SchoolBoy]

Hey thanks, thats what I was lookin for......

[quickslver50]

don't have too high of expectations, you'll set yourself up for a fall.
most people expect more HP than they really have, + different brand dyno's read different, some more some less.
most people leave there disapointed, including me!!!!

[f4fntm]

don't have too high of expectations, you'll set yourself up for a fall.
most people expect more HP than they really have, + different brand dyno's read different, some more some less.
most people leave there disapointed, including me!!!!
That being said: what kind of numbers do you hope to see, Nelson?

[WHTLTHR79RS]

IF he gets to the dyno and pulls more than 85 HP at the rear wheels, I'm taking his keys away until he paints the chicken coop.

DAD has spoken....

[f4fntm]

IF he gets to the dyno and pulls more than 85 HP at the rear wheels, I'm taking his keys away until he paints the chicken coop.
Watch yourself, Neil - he'll be choosing your retirement home before long. :P

[DELETED]

IF he gets to the dyno and pulls more than 85 HP at the rear wheels, I'm taking his keys away until he paints the chicken coop.
Watch yourself, Neil - he'll be choosing your retirement home before long. :P


That's my defense when my parents are being meanie heads... "How does a retirement home overlooking a New Jersey turnpike sound?" :P

[SchoolBoy]

That being said: what kind of numbers do you hope to see, Nelson?

I think my Friends 89 should pump out 260-270 horse I think, thats why I want to see.....

Now if you think I am going to run mine, your NUTZ, or better yet, If you buy my rebuild I would be more than happy to put it on the dyno...... Got 4 grand to spare, you could call it charity! :lol:

[f4fntm]

That being said: what kind of numbers do you hope to see, Nelson?

I think my Friends 89 should pump out 260-270 horse I think, thats why I want to see.....

Now if you think I am going to run mine, your NUTZ, or better yet, If you buy my rebuild I would be more than happy to put it on the dyno...... Got 4 grand to spare, you could call it charity! :lol:
Four large? Aren't you gonna do the work, under the close supervision of the Elder One? Should cost well under a thousand...

[SchoolBoy]

Four large? Aren't you gonna do the work, under the close supervision of the Elder One? Should cost well under a thousand...

Ya four large is max for the machine work needed on the block to hot tank and overbore, and the raw parts need to make it run.... Yes I will be putting together myself....