Single pump, SB 66 and 120's = 918/2000 !!!!!

I always dyno in 6th. Only made 659 with 120's, 85% pump, and a bullet. And that's WITH the west coast correction factor. :)

Didn't luken make 650 ish on johns dyno with stock injectors?
 
So Im confused... did he have a silver 66 or a e.d charger and did he have 120's or 200's? what programing?
 
I would prob. call bs aswell unless he has a custom e.d charger and 200's then it might be possible.. but not off a true 66.
 
Right !
I'm gonna trash my twins and drop down on injector size....I've got this ALL phucked up. LOL
 
I'm a little more intrigued than I was before to dyno at Sarver April 2nd. They have a Dyno Jet. With Exergy 105%'s and MPI SS64 over s480 w/race cover I better not lay an egg.
 
Im not trying to start an argument, I'm trying to understand what you are saying...


TMONEYDIESEL said:
The reason the #'s are so high is because you dynoed in 6th instead of 5th which would have been 1:1 which would have given you a real world # of what your engine is truly making.

The higher gear of .73-.79 gave you a higher transmission influenced #.
Click to expand...
I get this...I do believe you will make more power in 6th on a 6 speed and 5th on a 5 speed than the 1:1 gear. How much? I believe its minimal, especially from the times I tried both (10hp in my case).

TMONEYDIESEL said:
Your dynoing in the wrong gear, your motor will load better in 5th, 1:1 is the actual power output of your vehicle.

Your manipulating your #'s and probably close to blowing that tranny sky high loading it up in 6th like that.
Click to expand...

My motor has loaded better EVERY TIME in my tallest gear than my 1:1. The only exception to this was on a L&S dyno where the load cell could bring my truck to its knees in 4th, yet in that case, 4th vs 5th gear made no difference in hp.

TMONEYDIESEL said:
One of the most common differences when conducting roll-on power tests on a dyno is in the gear used during the test. Although 4th & 5th gear (depending on tranny)has been the standard, some dyno operators prefer to use a higher gear, and now 6th gear, which can distort comparisons. Power readings recorded in 6th are generally higher than those performed in 5th gear. Generally, the higher the transmission gear, the greater the engine loading and higher the power reading will be. Since the higher gear ratio slows the engine’s acceleration rate, less power is required to accelerate the rotating and reciprocating parts.
Click to expand...

I get your point here about the acceleration rate. BUT...if thats the case, then my truck with 3.73's and 37" tires is going to have a huge advantage over a stock tire'ed truck running 4.10's. Thats a way bigger difference than running 1:1 vs .073 or .076 or even .069...

TMONEYDIESEL said:
First i never said that his truck was dynoing 250hp more in 6th than 5th, in the NV4500 i believe 4th is 1:1 and 5th is .73.

To know your ACTUAL HP you dyno in 1:1 a chassis dyno is susceptible to gearing bias. Recorded power can be affected on a dyno graph by simply running the test car in too low or too high a gear. Dyno operators should pick the trans gear that is closest to a 1:1 ratio to avoid gearing bias. This ratio is 4th gear in most cars. In a 1:1 ratio, the two gears that make up a gear set are the same size. When one is larger than the other, either in a lower gear than 1:1 or a higher gear than 1:1, there are frictional losses that translates to less power put to the wheels. Also, too high of a gear that causes the test car to go to a top speed far greater than the available fan cooling capacity will produce invalid results.
Click to expand...

This is a tad bit contradictory to your point IMO. I understand where you are coming from, 1:1 is the most efficient gear. But you are also saying a higher gear will net higher hp numbers due to accel rates.

I think what this all comes down to is dynos... Its a comparison tool. The only way it can be used to compare accurately is same day, same dyno, same trucks. Then about all you can say is "I made more power than his truck did".

Again, not trying to argue with you TMONEY...Im just trying to see what it is I am missing here.
 
With my SB over a s480, twin modded pumps and Flux 5somethings I must be around 1800hp. now LMFAO
 
I've dynoed on Jet's and eddy current dyno's...in 1:1 gear and the OD gear.


Horsepower was basically the same from gear to gear, at anything from 250hp to 550hp....The torque was different by usually 100ft lbs from 1:1 to OD.

And IMHO, if we're talking actual power, in a truck on dyno's built for cars, then we need to use OD to account for the difference in the weight of the truck, versus the weight of the drum...at least on an inertial dyno. Eddy current should be a non issue!


Also...dynoed 551/1083 on an eddy current dyno in 4th gear (Auto, .69)...ran 101 at the track at roughly 7400 lbs...calculator says 533 at the wheels....pretty close??
Chris
 
smoke machine said:
The trucks got a hamilton cam, springs, pushrods, dampner. My trucks bn a freak since day one. I did 708 with my 90s, sb, and stock cp3. The reason iam getn the s400 was on those dyno runs I pegged my 2k pyro. She gts hot fast and that's with a hellman IC and as much cooling help as I can get
Click to expand...

^^ Just saw this ^^
Pegged a 2k pyro with 90's, silver bullet, + cam and IC??
 
smoke machine said:
001.jpg


all pulls were in 6th gear. got to about 1900 built 10psi and let her eat.

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

thats a mid 800 pull we tryd to get 15-20 built before hitting it it surged a little as you can here so we went back to 10psi
Click to expand...

Was there any correction factor???
 
TMONEYDIESEL said:
First i never said that his truck was dynoing 250hp more in 6th than 5th, in the NV4500 i believe 4th is 1:1 and 5th is .73.

To know your ACTUAL HP you dyno in 1:1 a chassis dyno is susceptible to gearing bias. Recorded power can be affected on a dyno graph by simply running the test car in too low or too high a gear. Dyno operators should pick the trans gear that is closest to a 1:1 ratio to avoid gearing bias. This ratio is 4th gear in most cars. In a 1:1 ratio, the two gears that make up a gear set are the same size. When one is larger than the other, either in a lower gear than 1:1 or a higher gear than 1:1, there are frictional losses that translates to less power put to the wheels. Also, too high of a gear that causes the test car to go to a top speed far greater than the available fan cooling capacity will produce invalid results.
Click to expand...

You were saying his numbers were skewed by him dynoing in 6th and everyone saying that he should have only made 650ish. 900-650=250. You didn't say it directly but that's what you were getting at and I'm sorry dynoing between 5th and 6th is not going to cause a 250hp difference.
 
His #'s are skewed, and again I never said dynoing in 6th was netting him a 250hp increase nor was that what I was gettiing at. If people don't want to dyno in the correct gear to see there actual HP and would rather make them selves feel better by seeing a # inflated by a higher gear ratio then everybody go ahead. This about being true to yourself and others.

:hehe: :hehe: Im out my head hurts and I've got the flu! FML
 
Chris, on that same dyno my truck hates life!..lol I weigh in at 7400lbs my truck went 115 in the qtr when it said my truck made 650hp at the wheel... idk didnt make since. calc. says 763..
 
You must log in or register to reply here.
Top