I just installed the APS Plenum about 2 weeks ago and after about 200 miles I can tell a significant difference in the upper power band in 3rd and up (it pulls harder). I am guessing 10-12 horsepower. So with this newfound power I want to get it on a dyno. I had it on a Dynojet back in Georgia in July of '04 and of the three pulls it put out 254whp and 248lbs/tq (pulleys, injen cai, jwt flyweel, stillen exhaust). I have since moved to San Diego and have added the Technosquare ECU and the APS Plenum. I figured I should have gained about 17-20hp. After vising a Dynojet today I am at a loss. I had three pulls and they go as follows:

236whp/220tq, 236whp/229tq, 238whp/222tq

Of course I am pissed. No fan was used and the temperature on the last run was 93 degrees in the garage. Even without a fan I assumed better numbers. I know you can't base a dyno here against one across the country or even dyno to dyno but these number have to be off. I know my z pulls much harder than a stock and it's been proven in a couple of races here and there. Could this dynojet not be calibrated right or faulty? Before I get too worried I am going to get it done somewhere else. If anyone knows of a creditable dyno shop in San Diego and has had reliable numbers please let me know.

Here is another topic with conflicting thoughts. What gear should our vehicles be in when doing a run. At Dynolab in Georgia they did the run in 5th gear (they said that was the 1:1 ratio). Whether it's correct or not I am confident my 254hp run was pretty accurate. Today in Escondido the guy insisted on 3rd gear. And after picking up some parts today at Pann Auto the guys said they did their runs in 4th gear. What gear is correct for the Z?

Thanks for the input.
aAron- '03 Performance - San Diego[B]

 

5th gear is 1:1. But 4th will work to there isn't that much of a difference between them. 3rd is the wrong gear altogether.

 

well the first thing I thought of when you said you moved from Georgia to California is you moved from 93 octane to 91 octane. Probably didn't do much in power, but maybe a little.

Also, no dyno is setup identicle even if it is the same brand. The only way to truly compare gains is if you dyno on the same dyno you used before with very similar natural circumstances (temp, humidity, altitude, etc.)

 

how's your a/f?

 

Were your numbers corrected? You could have done a high actual number at the first place, and then had an SAE correction at the 2nd place. That 2nd dyno that insisted on 3rd gear-dont go there again. Those idiots should know 5 is the 1:1 gear. I dyno'd 1X in 4th gear and it read low as $hit for some reason 212whp, 5th gear pull next read 260whp. On some dyno's there isnt a difference between 4th and 5th, but 3rd gear, that is way to low. Even though it should technically dyno higher in 3rd gear I have found with my Z and others that 5th in the 6 speed is the gear to dyno in. I hate when shops say well thats 140+mph so do 4th, I do 5th or I dont dyno, the dynoje is good for 20mph why do they care? Check your dyno correction, if they are both SAE go to another dynojet, dyno in 5th and use the SAE or STD correction for both and compare. Even then some dynojets read a few hp higher than others.

 

^agreed

 

Exactly. Dynos are tuninig tools not bragging tools. You cant compare them. There are too many factors.

Also there is a big difference in East Coast 93, to Ca 91.

 

Check out The Dyno Shop in Santee, they have a Dyno Dynamics unit that give consistent numbers. Also check out PowerTech Imports in Miramar. What shop were you at in Escondido?

 

Hehe if he goes on a dyno dynamics it will really be a blow to the ego. They read very low, usually known as the heartbreaker. My favorite dynos though, they are awesome!

 

Well I've always thought the Mustang dynos were the lowest and I actually awlays called them the dream killers myself..lol. The Dyno Dynamics is pretty accurate though. I put down 234 stock and 238 with POP Charger on the one at the Dyno Shop. Next dyno was a Dynojet with an Apexi exhaust added and it put down 240. Since then all dynos on my car have been Dynapack.

 

The dyno shop in Escondido is called Shear Speed. He stated that 5th gear was wrong due the excessive speed and strain on the transmission. Oh well, I should have known when I saw him dusting off the dyno computer.

 

Sorry man thats funny. That guy is a tool, dont go back. And next time you go dyno, ask when you schdule an appointement if they have a problem dynoing in 5th which goes to 142mph, if they do hang up

 

Hmm never heard of the joint. I've lived in Esco for a while too and have looked around at shops with dynos. That guy is definitely off the reservation. 5th gear is 1:1 and should be used. Try the Dyno Shop or AutoTech Motorsports

Link to Autotech: http://www.autotechmotorsports.com/dyno.htm
Link to the DynoShop: http://www.thedynoshop.com/

 

I think I had the lowest dyno possible on Mustang dyno.

180 HP 181 TQ on third gear.

This guy said he can not do dyno on fifth gear because he can not get to redline.

Cost me $75 for 3 pull.

 

So why not do it in 4th? At least that would have been "more" accurate.

 

He can't do 4th for the same reason that he can't do 5th.

I also have question about A/F.

Do I need to install my car with wide band O2 sensor so that the dyno place can give me accurate A/F reading?

 

No, if they have a wideband they use a tail pipe 02 sniffer....

 

+1 to almost everything here....

Have them send you the dyno files... You can download a free viewer from the dynojet website. Then you can look @ your runs anyway you want!!!

This will also tell you what SAE correction they use...

TorqueFreaks uses .97 SAE, and I 'feel' there numbers are ROCK solid. (we have 92 pump gas)


I've seen them dyno a lot of cars, and watched the numbers. (Over 40 cars this weekend.) They pretty much spit out manufacturer numbers... (If you correct for drive train loss.)

 

5th gear isnt needed on a load based dyno...and even on an inertial dyno, the numbers are within the range of sampling error.

I prefer 4th gear, as many dynos dont like spinning the rollers at nearly 150mph...and for what point?

 

Sharif, I have dyno'd the Z at 2 different dynojets. At both I have always dyno'd higher in 5th gear. One place at that time was 256whp in 5th, 253 in 4th, very close. Yet at the other dyno, I did 212whp in 4th and in 5th the very next pull with no break other than to see the numbers, I did 260 whp Have any idea why such a huge difference between 4th and 5th gear at this dyno? Kinda threw me off....