Any one remember when the first Ls1's posted a Rear Wheel Hp OF 400
"Many claimed it wasn't possible with H/C Package" Now I have seen numbers
that are crazy and as high as 460 HP with mn6! Lets see 460 RWHP, 15%
drivetrain loss = 541 HP divide by 346 cubes Wow thats 1.56 HP per cube
Naturally Aspirated , production bottom end, on pump gas! Most top
Engine builders would be doing cartwheels at 1.3 HP pure Cube!
I haven't posted in a long time Heck I had to get a new name and password I am
Ron from Pro Auto Tech I have 20 years experience in Engine Management
and have been a Certified Instructor of Techs for 18 years, I have been
working with the Ls1 since its birth. I think Dynojet has done a wonderful
job marketing its product. However I would like to provide some helpful info!
The load on the Dynojet is not the same as the road, your a/f will change
as you leave the dyno typically leaner! Proof Turbo Vehicles never reach max boost on the dynojet as they do on the road. Dynojets do not
measure Torque They measure HP and do the math with rpm to arrive at torque! Proof try to get a torque number without rpm on the dynojet.
Real Dyno's that measure torque and arrive at Hp are few and far between
if you find one you can tune to the correct load These dyno's will
have strain guages and operate with a water brake or eddy current
such as Superflow or Land and Sea. Many make there final decisions on
performance mods based upon dyno numbers seen in posts. Be ware
big numbers can be made on a dynojet without actual HP at the engine.
Try this on a dynojet baseline and then do this free mod put 65 psi in
the rear tires see what that did for you, you will have a nice gain how would that work at the track. What would happen if someone would drill some
holes in the dynojet drums! I know there are vendors that are good
a lightning things up! If you do not beleive me talk to the engine builders
that have been around a while and what they think about these large
dynojet numbers, Guys like Myron Cottrell TPIS, Frits Kale Katech,
Reeves Calloway Calloway Cars Doug Rippie DRM Grahmn at Lingenfelters I bet they don't beleive the numbers either. I am just
really leary of those who blow loud horns abouth these unrealistic numbers
I have a Land and Sea Chasis Dyno here in Fort Myers FL Any one who
has these big Dynojet numbers I will dyno for free for comparison, I have
32 Channels of data acquisition , you name it I can compare it to Hp & Torque
Mass Flow Air/ Fuel Knock and much more with real road load simulations!
In closing I am sure Iam going to get bashed but don't make your decisions
based solely on what an inertia dyno reads.

[Modified by Gooseman, 2:21 AM 9/18/2003]


[Modified by Gooseman, 2:29 AM 9/18/2003]

 

Ron, this may be true, but the only thing that really matters is the relevance to other runs on the same Dyno..

Let's put it this way.. I had my car done a few weeks back on a Dynojet.. I pulled 345rwhp. There was a 2003 Z06 there and he pulled about 355rwhp or close to that...

It was more important to me that I pulled 10 less hp than a Z06 and all I had was bolt on's. All that matters is if you compare on the same Dyno..

If we both ran somewhere else and on a differenct dyno..And say ran 20hp less across the board....We'd still be 10HP diff... ;)

But I do agree...some of the numbers are pretty trumped up..


[Modified by chuckster, 9:38 PM 9/17/2003]

 

:cheers: :thumbs:

 

Good to see you on the forum :cheers: I've heard alot about you :yesnod:

 

Dynojets do not
measure Torque They measure HP and do the math with rpm to arrive at torque! Proof try to get a torque number without rpm on the dynojet.


HP = TQ * RPM/5252

I fail to see how it is "wrong" to measure HP and derive torque... I can simply re-arrange the equation as such (simple middle school algebra here):

TQ = HP*5252/RPM

Gooseman- while you might have some very valid and awe-inspiring point, your arguement is flawed for a few very substantial reasons:

1) You failed to provide a logical and coherant proof. Ie, you made a poorly written, poorly contrived, poor executed statement.
2) You failed to prove why your opinion is valid. You implied that calculating TQ from HP is bad. You failed to explain why.
3) You have two posts and you bash well repected tuners.

For example-
Proof try to get a torque number without rpm on the dynojet.
Ok- try to get a HP figure using your torque calculation dyno without RPM. IT CAN'T BE DONE!

You bash dynojet and numerous other vendor's for their "trumped-up" numbers, but you provide poor logic, no proof, and have two posts to your name. I'm sorry, but I don't recognize your name....

FYI- The S2000 makes 1.2HP per cube, completely stock, with a full Honda warranty.


[Modified by Umrswimr, 9:10 PM 9/17/2003]

 

I was wondering why I have not posted in so long! My point is that it appears
there is too much faith in the dynojet and inertia dyno's have flaws.
Calculating Hp from Actual Torque is more accurate !
Torque wins races HP appears to sell parts! I did not bash any vendor
Chill Out Life is too short Changing the tire pressure or what gear you run
in will not change the readings on a real torque measuring dyno is my point.



[Modified by Gooseman, 3:22 AM 9/18/2003]

 

:iagree: but he has a point some of these numbers are wild......... :yesnod:

 

I've seen higher h/c numbers than that here lately.

You may know all the ins and outs of dyno's, and I'm not disputing any of your technical points, only because I have no freaking clue about it, but...

To question your point that I quoted above...3-4 years ago, yes, cars where dynoing much lower, and 400, 420, 450rwhp h/c cars were milestones...but they were still getting the numbers from the same dynojet dynos.

If my car today dynos 330rwhp on a dynojet...and I add a modern h/c, take it back to the same dyno and get 450rwhp...did my car really inprove 120hp, or did the dyno suddenly become inaccurate?

That is my only question.

:cheers:

 

Just my O2
take them to the track
I don't care if it makes 300 Hp at the wheels, but it run's mid to low 11's.

But that's my opinion !

You know what they say about that ! :lol:

Just make a educated decision

Listen to ALL the facts.

 

While there may be some actual mathematical error with an inertial dyno, the simple fact of the matter is (as was state earlier) that it's not the NUMBER that matters- it's the difference that's most important. However, I still fail to see how it's less accurate to measure one than the other. It';s a simple equation- what is making it not accurate to meaure one and calculate the other? I'm not flaming- I really want to know.

Horsepower wins races. I don't really believe that is up for ANY debate....

We'll start with this very simple example: http://vettenet.org/torquehp.html

Life is too short, and I'm plenty chilled. :) You seem to have a strong following (by the two folks that instantly recognized you), but I'm not really convinced here.... Help me out....

 

Lots of intelligence in the replies here. The real beauty is that a mathematical equation is functionally perfect, at least at the sophmore level required here.

What's in question is the functional accuracy of the equipment to measure a specific constant. Whether torque or HP, the equation is interchangeable.

I like the point Chuckster made. Apples are apples, etc, etc. If everyone is measuring their johnson with the same yard stick who cares if it's inaccurately graduated? :rolleyes: Everyone will know who is who. The rest involves skill and as far as I know the only electronic equipment they have to measure that is a clock and 1/4 mile of smooth asphault..

JMHO & $0.02 :cheers:

 

:iagree: :iagree: :iagree: :thumbs:

 

There is no way to get HP without getting torque and RPMs. HP is a made up value based on the formula you show. If Dynojets measure HP then a number of calculations are built in.

 

Thats the point are these Ls1's really 50 more RW HP what changed?
flow numbers from heads a little better camshaft's you can make more
Hp at the top but usually suffer a torque loss low. Compression ratio
11.0-11.3:1 still the same. There are some engine building formula
rules that do not add up to the claims. Fact big dyno numbers sell parts
can dyno numbers get bigger without the engine making more HP!
Several ways,Lighten the rollers, screw with the weather inputs, Reduce
friction at the tires, more air, less surface contact, make runs in overdrive,
If you make a number that is greater than 1.35 HP per cube on a
Naturally aspirated LS1 not over 11.0:1 Compression 346 Cubes 93 octane
You are doing better than some of the top engine builders in the country!
Especially if it lives! I have been doing this a long time and I do not
beleive these 440 + RWHP Numbers Let the bashing begin

 

Well...For what it's worth, Dyno Jets do not exactly "Measure" HP..or Torque for that matter. It simply has an optical encoder that measures drum speed. The rate of drum accel computed with the delivered inerta (weight) of the drums. At this point toss in some RPM inputs and calculate away.

That being said, The Dynojet is certainly very generous is terms of actual HP/Torque. But, I certainly feel there are a lot of dyno's (Reguardless of type) around this country that have what I will call "Customer Satisfaction" ****. There are many members on every forum that have sigs and so called dyno sheets that flat out defy the laws of physics. I often look at these so called examples and look for tell tale signs..like injector size that wont support that level of power.
I'm sure guys will flame away, but I am very confident the longer this goes on and the more educated people become, that this will become a thing of the past. In this area it's comming to a head, Vehicles with so called 500rwhp get a beating from less than 400rwhp cars and the ever popular 500 rwhp cars running 12.xx at 11x mph.

Ok.. :rant:

Phil



[Modified by RoadRebel, 10:51 PM 9/17/2003]

 

Thanks Road Rebel

 

From what I've seen, it's mostly cam numbers, and some added compression in some cases. When I joined this forum, a 227 duration cam was considered quite radical for a street (daily driver) type car, and no one did it without modifying and porting the heads. Now fast forward to today and people are throwing 236/240 cams on stock heads and getting awesome numbers and still have great streetworthiness. It's becoming well known these LSx engines respond very well to what's previously been considered too radical of a cam, and knowledge of tuning techniques is definitely helping this. I don't believe the potential of these engines has fully been discovered yet, and the numbers will continue to grow as more things are experimented with.

As you said, a radical cam will show the #'s at the top end, and those peak #'s do make them somewhat dyno queens, but the numbers are there, and the numbers are coming from the same dynos as 2 years ago.

:cheers:

 

:lurk:

 

...
If you make a number that is greater than 1.35 HP per cube on a
Naturally aspirated LS1 not over 11.0:1 Compression 346 Cubes 93 octane
You are doing better than some of the top engine builders in the country!
Especially if it lives! I have been doing this a long time and I do not
beleive these 440 + RWHP Numbers Let the bashing begin


I mostly agree with you on your "bashing" of inertia dynometers. It would be interesting if some people could find a Mustang dyno (MD-750 or such), and compare numbers.

But I completely disagree with your general statement that anything over 1.35hp:CI is not likely possible. How much hp do you think a NASCAR engine puts out? ya, right around 2hp per cube. now you will say, "but look, their rpm range is way different... compression, etc.. blah blah blah". I know. I am just trying to make a point that 1.35 isn't all that much in the grand scheme of things.

So on to "street engines". would you say 600hp @ 6500 rpm with 10:1 compression on 92 octane gas with 360 cubes naturally aspirated is not possible?

how about 1050hp out of a NA big block chevy, carb'd, running pump gas, is that not possible?

or are you inferring that an LS1 engine because of its design is not capable of handling/making greater than 1.35hp per cube and still remain streetable/dependable?

head design has come a long way recently, and we're not talking about slapping some "camel back" 350 heads on an engine and expecting 500hp. in my opinion, its quite possible to see 1.35 hp or greater per cube. maybe i'm delusional.

 

From what I have seen posted by those that dynoed on a Mustang dynometer there numbers still do not folly by 40+ RWHP.

True they wil suffer slightly maybe 10-30 but 40+....come on!

The reason dynojets are so popular, is because of their price and user friendliness.

They still can make great tuninhg tools and people that are in the business of Nascar, AAA Fuel Cars, Pro Mods, Turbo's, etc...normally will use an inertia dyno.

As mentioned in this thread. It is good for comparison. Whether in the same dyno or not, people can compare to some extent. No matter what no dyno will over come real world variables, and all numbers have to be corrected.

Like stated before....take it to the track!

As for horsepower/cubic inch.....so what you are saying is that you have a hard time seeing these cars making 449BHP. Now I know there are numerous motors making that power, whether on a mustang or dynojet! To think about it 18 years ago.....maybe a little far fetched, but today with the head designs and technology.....seems too easy! Didn't GM claim 385BHP for 2001 Z06 (1.11 BHP/CI) And 405 BHP (1.17) from the 2002. I am sure some testing went into that!!!!!

To think that you cannot pick up 45 BHP (0.13 BHP/CI)over stock with bolts ons or mods pretty easily, seems a little ridiculous!


[Modified by z0sense, 10:58 PM 9/17/2003]