This must be this weeks installment of the Dyno Wars thread.

Apples to Apples comparison requires the same conditions;

Dynojet 248 is the most common (assuming the opertator/shop is honest and not trying to sell parts or a tune).
SAE correction (not standard or no correction).
Smoothing 5 (not "0"" or "3"

We have a pretty full collection of runs on LS2's over the years, they seemed to balance at;

Stock LS2 A6 = 335RWHP from 400 rated = 65HP loss
Stock LS2 M6 = 345RWHP from 400 rated = 55HP loss

LS3 "should" have the same losses so;

Stock LS3 A6 = 371RWHP from 436 rated = 65HP loss
Stock LS3 M6 = 381RWHP from 436 rated = 55HP loss

My '05 LS2 M6 dyno'd a stock best of 346RWHP on different Dynojets
My '08 LS3 A6 dyno'd a stock best of 373RWHP on a Dynojet

I can only assume that the 3 different Dynojets my '05 was on were all accurate since they all fell in the same SAE corrected range, I'll assume that the 1 dyno on my '08 A6 was accurate since it fell into the same parameters.

The Stock 400RWHP M6 Dynos are a joke, either the dyno isn't set up correctly, it's not a Dynojet 248 or the owner/operator has a reason to give you higher numbers.

Use some common sense, there aren't THAT many Factory Flukes, GM has to verify the motors to a strict Federal standard. We all want big numbers but lets keep it honest.

 

To go along with Hal, my stock 08 C6 M6 dynoed 380.75 rwhp on a Dynojet 224x.

 

The ls7's dyno at 450. Same 55 hp loss.

 

Does somebody have a really excellent dyno graph picture with hp/torque on the same scale (crossing at 5252 RPM) and with the RPM labelled? I need this picture and can't find a good one that will be good for printing.

 

Good point. Looks like drive train design is more important than displacement or HP per Cubic Inch.

 

A case I'm familiar with, was GM HighTech Performance magazine did a test on a modded ls2 at Liverrnois Motorsports. The before dyno was 402 crank hp.(on a stand).They added Livernois stage 3 heads(cnc'd 243's) and stage 2 Comp cam, 232/232 .595 114 lsa, Kooks 1 7/8 LTH and what looked like a double C&N air filter and open header exaust. After tuning it ended up with 544 crank hp, a gain of 142 crank hp. A Livernois customer has the same setup except for Corsa Sport mufflers and a Hallteck Stinger intake which can loose maybe 5-10 hp.Who knows a few anyway. This car dynos at 472 rwhp.If you take away the 142 hp gain you end up with 430 rwhp stock. Since the stock car should get 340-345, the net difference is only 10-15 which is within a reasonable margin of error since the intake and mufflers were different. I personally think adding hp through mods has very little effect on drivetrain loss. JMHO. Have seen many posts of people trying to figure crank hp using 12%, 15%, 18% 20% or whatever. but in reality the m6 looses 55-60 and the autos loose 65-70 and thats about it.Your thoughts? These are Dynojet numbers.

 

These are my baseline numbers, and my numbers with a few dyno runs and some tuning. The Vette is stock other than tuning.


Cortvet

 

As most agree 380 stock is about right. Most basic tunes on nearly stock cars yield 5-10 hp. I see you got 15, nice job.

 

Now this is just getting funny.

I had my '08 A6 retuned on the same dyno as CORTVET. My performance mods include CAI, ported TB, full Z06 exhaust (heads to tips).

The 1st pull using the previous tune as a baseline made 372.15, which was good enough to run 11.98 @ 120+ a week earlier.

After 7 more pulls I ended up at 381.96.

CORTVET had 378.82 stock and 393.97 with just a tune.

Rock n Blue 08 said he made 433 with mods and ran 11.98 @ 120.

I initially made 6 hp less with mods and tune than CORTVET did stock and 61 hp less than R n B 08, but still matched his time. Then we squeezed out another 9 hp.

So am I way short on hp compared to most others? Or do my 1/4 mi. results show that others have inflated numbers?

 

Thanks very much!!! I started this thread almost a year ago and you are the 1st one to finally put all the variables on 1 page. It kills me how alot of guys ask or tell about dyno #s and they don't mention tranny!! You have it broken down very nicely......thanks

 

The base pull is normal, usually around 370 for an auto and 5-10 for a basic tune.The Vararam shows no gain and other CAI show 0-10 hp. The ported throttleboby is worth 0-2 hp, so nothing there. The z06 headers are worth 10-15. It looks like your mods are worth 10-15 hp at most. Picking up 9 hp is at the low side but not far off. Your car seems to be running really good, that 11.98 for 372 rwhp is outstanding. I've been following the thread and most of the dyno numbers expressed are typical for what mods they have. One person posted I think 466 hp with stock heads and no Fast which normally run 425-430 range. Didn't look at r and b 08's mods, will do so now.

 

I see what your saying on Rock and Blues 08's numbers. His car is a manual, so 378 stock is right on. Long tube headers are usually worth 25-28 hp, the tune 5-10. 30-40 would be the usual gains for these mods. He picked up 65. Don't want to start a war here, but it appears the dyno numbers are off. Why, I don't know and don't care. After reading hundreds, if not a thousand threads on dyno numbers and mods I've never seen anyone come anywhere near 65 hp. I wouldn't use that particular response in evaluating your your cars numbers. Running the times that you do should make you real happy.

 

Well mine came in the lowest yet. Mustang Dyno before mods 320HP and with 365rwhp. I have a 08 Z51 manual. Headers, thermostate done. It has the NPP exhaust. Changing the intake will that make a big difference?

 

Mustang dynos traditionally read lower than dynojets, but yours is really low. I'm not that familiar with mustangs but I would think you should get 350 or so with a m6. Headers and a tune should yield 35 or so, and that you got. 08's have great heads and the headers tend to pick up a little more than ls2's. On a dynojet you'll probably show 415 or so.

 

Those are the only numbers I care about. 1/4 mi. MPH is a great indicator of real HP. Dynos are a great tool to get more HP from any particular car, so the MPH can increase. The dyno numbers have no value, other than bragging, once the car leaves the dyno shop.
Show me the timeslips or line up next to me if you want a true comparison of power.
I not knocking R n B's dyno numbers, but if our ETs and MPHs are identical, but our dyno numbers are 61 HP different, it certainly shows dyno numbers are not a valid means of comparison.


My first dyno pull, when bone stock, was on a Mustang and only showed 306 HP. It showed 321 after adding CAI and a tune. I ran consistant 12.20's @ 118-119 mph, which was a .2-.3 et and 2-3 mph improvement over stock.

 

Like I said, your numbers are reading way too low for what you have. Your 1/4 mile time and speed indicate you are running 400+ rwhp.(based on a dynojet) There are plenty of member listed mods with track times you can read up on, do a little research and you will see where you are relative to them. You could spend $400 and get a dynojet reading. A stock 380 rwhp ls3 runs 12.4-12.5. Each 10 hp should reduce your et by 1/10. In order to run 12.2 you would need to be at 400 hp. If your car really only had 320 hp it would run in the 13's.Hope this helps, IMO you just have a bad reading.

 

Bingo!! Could not have said it better myself, except to say in the 1/4 mile, ET Rulz, not mph.

 

I second that motion.

 

I was thinking about your comment today and remembered Livernois did a dyno on a ZR1 last fall. Looked it up, at 638 hp crank, it got 571 rwhp and 540 rwtq. Even at that level the drivetrain lost 67 hp. All the c6 drivetrain loses are within are within a narrow window and seem somewhat unaffected by hp and tq.

 

my c6 hit 419rwhp ona mustang dyno and 429rwhp on a dyno jet with no other mods.