Gman which shop did you use?

 

dyno's can be configured and manipulated to put out whatever number the dyno operater wants. SImply placing the tmep probe incorrectly, using the wrong tyre pressures and other parametres will ultimatly give false readings from a dyno. People should never compare dyno's from different operaters, let alone different brands. Dyno Dynamic dynos have a Shootout mode designed to allow comparision between DD dyno's. Its an addon which costs around 10k doesn various things like settings ramp rates etc etc. But even still, operaters can manipulate figures!! A dyno is a tuning tool. If u want to compare, be aware that they are simple to trick and make lie.

 

as i have said 100 times, the dyno dynamics claim of how much you should increase their numbers to match dynojet only seem to make sense on the na Z's... the turbo ones always were obviously inflated at the dyno dynamics 1.15 ratio.

there is no static ratio, because the dynos dont work even remotely the same way. not even CLOSE. its just not that simple, and never will be. it looks like around 450-550rwhp area the dynojet and dyno dynamics seem to read decently close... but whos to say for sure, it just happened to on this one car.

either way, THANK YOU very much. I like seeing that someone actually took the time to prove this.

 

I'm probably that local person (?)


Dyno Dynamics was 401hp (DynoComp), the subsequent Dyno Jet (AZDynoChip) was 446hp for ~11% increase.

Problem being - I've found a wide variation (+/- 15 hp) between the valley DynoJets themselves (v. Intense, v. NOPI mobile DynoJet, etc.)

 

you have to make sure that the dynojet correction is the same. while there is absolutely no wya for the operator to adjust the numbers on a dynojet 248 (other then operator error... incorrect strapping, wrong tire pressure, incorrect enviroment sensor placement), there are 4-5 different standard corrections available. The most popular is SAE, but some guys use other ones or even uncorrected - which is what the car really just laid down, before any temp/humidity correction is equated.

 

Thanks for posting this
I am not sure why most people think this needed to be proved AGAIN, ... it's like all of a sudden, this was an issue b/c "350Z's" started making power!

Why doesn't everyone read on "other" forums before making so many comments about this and that...? NO dynos are going to read exactly the same, whether they are the same brand or not. Dynos are TOOLS to tune, that's it. We just get a pretty HP and TQ chart to hang on our walls to brag about...

This is ANOTHER reason why taking a drive down the 1320 and getting some trap speeds helps to tell you what kind of power your car is laying down...

 

It's just a number...like NoLimit said run the 1320 and see if you pick up some MPH. At your power levels MPH is probably an easier number to duplicate vs an E.T. (ET = traction, MPH = Horsepower).

Also, do they use a different correction for turbo vs NA cars? For the same reason turbos lose less power with altitude the correction should be different between NA and turbo. Best bet is to always stick with the same dyno and same correction.

My $5.10
Dave Lum
www.Datsuns.com

 

Lujan motorsports in Doral.

 

Actually, the shootout mode is now included in the normal DD packages...we have it on ours. It very accurately simulates "Crank" or engine hp, rather than whp, and we've tested it...very very accurate. In shootout mode, all of the operator parameters are locked out, so the user cannnot add "Additional" correction. Just some info for everyone.

I think Phunk hit it on the head. And you may recall, I used to be a fan of the additional correct, but when we purchased our dyno, we decided to eliminate it. Every dyno is going to read differently, based on a myriad of diferent variables. The tune, and change from baseline is the true reason for dyno tuning. If my numbers are lower than a Dyno Jet next door, I really couldnt care less. The customer's butt dyno usually tells them the true story.

 

He said Butt dyno lol funny

 

I forgot to post the dyno chart the other day. Here it is.

 

Cool, thanks for posting that - do you have any runs starting from a lower RPM like 2000rpm so you can see where the turbos start to spool? From this chart it looks like about 3500rpm but hard to tell where the pull started. What turbos are you running, the TDO5H-18G? How much boost?

I just ordered JWT's manifolds but haven't bought the turbos...yet.

Dave Lum
www.Datsuns.com

 

+1 was gonna say they started it kinda late...

 

Nice flar trq curve..yummie. Alberto..thats an awesome new avatar.

 

Sure...from 4000RPM on up. How often is a street car above 4000rpm unless you're racing - hence my earlier post about a run that has lower RPM numbers. Have you seen JWT's dyno chart? 380ft-lbs at 2250RPM (what's your RPM@60mph - probably about that yeah?)
http://tinyurl.com/pfyv3

FWIW: Not intended as a slam because that's a monster HP number in any case - I sure wouldn't mind 500+RWHP, that's for sure.

Dave Lum
www.datsuns.com

 

Sounds like a slam to me! IMO, most street cars ARE above 4000 rpm when you get on it if you're in the right gear. Are you normally @ 2000 rpm in 5th when you decide to hit it??

 

Thanks And yes that TQ curve is a wonderful thing, car must be loads of fun to drive with all that power. One day I may make it to that level

 

OK you have a point, for most street battles (Oops I mean dragstrip work ) you are in the RPM range of max power so yeah thet power will kick *** almost everywhere!

If you're autocrossing there are many situations where you want torque below 4000RPM - you can get a much faster time if you can leave the car in one gear for the entire run. For track days it's also beneficial to have a broad torque curve but GMan's torque curve is broad enough above 4K that it's likely not an issue.

Sorry, my bias toward a flexible powerplant came though. In addition to my fast car I also drive an early SE-R and it's a real bummer to *have* to downshift 2 gears just to get reasonable acceleration.

Dave Lum
www.datsuns.com

 

Sharif, nice site you have, love the splash page.
My name is Alberto and you mentioned your shop has a Dyno Dynamics machine. Which model do you guys own? We have a the 450 model (single retarder/axle).
Great machine.

One question, I am sure you guys have tuned a Split Second FTC box on a SC engine. What is your take on that little box. Pros and cons.

Thanks,
Alberto

 

Dave, with the load based DynoPak in the example you mentioned, it is very easy to load the engine, create lots of boost, and then release the dyno. This results in a huge trq increase down low, but is not a realistic representation of the true trq the engine is making at a given point. On an inertia dyno, such as the one Gman used, the trq will build in a natural fashion...just as it would on the road.

There are lots of ways to make dyno charts look better.....preloading boost is just one example.