Post Recall Dyno Today!!!
#26
Zoom-Freakin'-Zoom
iTrader: (5)
Originally Posted by Brettus
having most of the same mods as you & dynoing them vs stock just last week I was around 172 hp on a Dyno Dynamics which by all accounts is comparable to a Mustang .
So 203 is quite amazing - are you sure you weren't spraying some nos in there ?![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
If you add on losses you are going to be up where Mazda claims for FW HP !
Can you ring the dyno people & ask them specifically if they have compared their mustang dyno to a dynojet .
Thing is - we want to know what is happening with your engine - it seems about 20-25hp more than anyone else can get with those mods.
So 203 is quite amazing - are you sure you weren't spraying some nos in there ?
![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
If you add on losses you are going to be up where Mazda claims for FW HP !
Can you ring the dyno people & ask them specifically if they have compared their mustang dyno to a dynojet .
Thing is - we want to know what is happening with your engine - it seems about 20-25hp more than anyone else can get with those mods.
i am going to get mine on the dyno before and after they replace my motor...
beers
![Beer](https://www.rx8club.com/images/smilies/beer.gif)
#30
Registered
iTrader: (3)
dont go dyno crazy here guys. Comparing one agaisnt the other ain't right. Our group in Ga have cars that range from the 170's to over 200(thats all n/a and stock ecu). things like plugs , wire's, coils, clean maf and a good cat can cause a wide differance. Heck we have had members to get 10hp out of a new set of plugs(nd the car was seemingly running well). Even with the dyno hp differance --when we go to the track one car is not really "pulling" the other one. I'm talking about on the straights--same exit speed out of the turn etc.
This car package does not dyno well.
The thing i noticed was the smoother transition at the differant intake steps. That looks good.
olddragger
This car package does not dyno well.
The thing i noticed was the smoother transition at the differant intake steps. That looks good.
olddragger
#33
RX8 and a Truk....
Originally Posted by shinka213
soooo....are we saying here that a mustang dyno doesnt give an RX8 accurate results...
please explain!
please explain!
I can't see anyone saying that. What I see is a healthy dose of "Good numbers, but without a context, they are just numbers."
![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
If the guy can go back in a week and have the same dyno #'s, that'd help. If he could run on another brand of dyno, for comparison, that'd help too.
![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
#35
Originally Posted by shinka213
soooo....are we saying here that a mustang dyno doesnt give an RX8 accurate results...
please explain!
please explain!
They / the operator can vary the load so that the engine can be held at constant speeds while such things as ignition and fuelling can be adjusted to optimum values at different steady state throttle openings and rpm's - extremely useful! Easier to fully set up a new engine management or carb system quickly and accurately. For this reason alone these types of Dynamometers are preferable for setting up and tuning road cars and moderately tuned vehicles where you are not just looking for "ultimate" power.
Unfortunately most braked dynamometers seem to use dual rollers on each wheel. These "trap" the tyre, cause slippage, heat, HP losses that vary, and can cause tyre problems. A single drum per wheel of 16 inch diameter or greater is far superior, as in the picture above.
Can be dangerous to certain very high performance, boosted, nitrous injected, or tuned two stroke type engines as they are already on the edge of detonation and heat damage. This mostly depends on the experience of the operator. Trying to hold a 450bhp turbocharged nitrous injected bike at steady full power is a recipe for an engine meltdown! In the real world its not a problem because they would be going at say 170mph in 8 seconds and then shut off! The correct ignition timing and fuel mixture for these types of vehicles is generally not suitable for continuous steady state non accelerating conditions.
Because of the fact that they CAN be calibrated, and in fact need to be calibrated from time to time, means that they can never be totally accurate. And that an owner or operator can "ahem" re-calibrate it themselves! Never trust a tuner to give you reliable figures! Most are honest but some are not! Its only too easy to make the results "look good" if you see what I mean...
Because of the fact that, the rollers are "wrong" in layout, and size on most of these, and because they use a dc voltage signal from a load cell connected to the "brake" to determine roller torque (torque x rpm or speed gives them the BHP) which in itself has a level of Hysterisis, and because this low level DC output is subject to electrical noise & variable resistance due to temperatures, errors from the analogue to digital conversion process etc, they can NEVER be completely accurate. Or in fact very repeatable. (unless the whole process is done digitally, which I have yet to see.)
Advantages and disadvantages of a modern computerised inertial or inertia dynamometer system
1st a word of warning... Because the principal of an inertia dyno is so simple there are rather a lot of really badly designed systems out there. Its hard to know which ones are good well designed systems, and which are practically useless. For a few clues click HERE
There is NO calibration ever required or possible on a good properly designed (not all are!) inertial dynamometer system. My own systems for example used a free running solid steel turned drum of 402mm in diameter x 562mm wide. All of the dynos I produced used this exact same drum. The inertial values were calculated mathematically from the density of the steel and the technical drawings, and integrated directly into the software. There are simply no external user parameters that could be changed to alter the "calibration". There simply is no need. So there can be no errors, or calibration requirements. If a healthy car / bike reads 56bhp on one dyno, then it will read this exact same figure on all of the others! Its just maths. Unlike braked systems there is no no DC voltages, nothing can change, no variations due to Hysterisis etc. Companies such as DynoJet do the same thing. In fact I took my own motorcycle to ten different DynoJet dynamometers in the UK over a period of a couple of weeks, and it / they read between 135 and 136 BHP on all of them, as well as on my own dynamometer systems. Nice to know your maths is the same as theres is! You simply cannot do this with any normal braked dynamometer systems, as they vary quite wildly due to the above and one or two other minor things like they all require Calibrating!
They are dynamic testing dynamometers only! This means that when you open the throttle the drum always accelerates. It is not possible to hold a steady "under load" rpm. So making changes to fuel and ignition maps is much more difficult. It is less good at this kind of thing than a braked dynamometer is. If your main job is to set up fuel systems across the range, for e.g., rather than absolute accuracy and repeatability you are better off using a braked dynamometer.
For deadly accurate back to back power runs when testing things like different lubricants, plug gap changes, different ignition coils, tiny jetting or fuelling changes, then they are superb! Its even possible to easily and repeatable see the effect of turning the lights on during a run! Try that on a braked dyno and the small difference is lost in the "noise" of the system. So for ultimate performance tuning, bikes, drag racing, etc they are preferable.
For example...
On this bike below! It was mine, but it does not like braked dynos (or rather having its rpm held at a constant speed) due to the sheer amount of nitrous being used in two stages. It detonates a little after being held at a constant 6,000 rpm for a short period. We were trying to get a fix on the mixture at this point, but this takes a good few seconds to stabilize. In real life it does not see 6000rpm for more than a second on the strip. So the heat build up on plugs / valves etc does not get time to start it detonating! After 6000rpm - no problem. We know this because a knock sensor and a data logger tells me so... Retarding ignition more at this point, or adding a touch more fuel stops this happening. But the bike is then measurably slower! So for some situations a dynamic run climbing through the RPM's is very important. Whilst some braked dynos can also do rpm "climbing" runs, it defeats the object of using one because then you may as well use a nominally more accurate inertial dyno as you can't check the mixture at any given RPM any more!
http://www.dynamometer.fsnet.co.uk/a...ynamometer.htm
I'll just change my full post cause I found this. The first is what they call a mustang dyno i think.
Last edited by Trekk; 09-28-2006 at 11:02 AM.
#36
Boosted Kiwi
iTrader: (2)
Awesome explanation Trekk . While on the dyno (two roller type) last week we must have done about 30 runs . I noticed that the first run we did each time gave an erratic reading (on the low side) . We then had to do two more runs that gave similar results to get a "true" reading .
#37
The Professor
Thread Starter
Okay, so I called the Dyno place about their Mustang Dyno and asked them how it compared to a Dynojet and they said.
"Our dyno is a Mustang and generally reads lower than a Dynojet. For example, we had a guy in here with a Supra the other day and he ran just at 700hp on our dyno, then he immediately drove it over to a Dynojet and he pulled at right around 800hp."
So, it looks like I'm set![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
It really does feel fast though, I've beaten g35s and SRT-4s pretty easily (they look very suprised
). For some reason a bunch of guys in trucks have been racing me lately.
"Our dyno is a Mustang and generally reads lower than a Dynojet. For example, we had a guy in here with a Supra the other day and he ran just at 700hp on our dyno, then he immediately drove it over to a Dynojet and he pulled at right around 800hp."
So, it looks like I'm set
![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
It really does feel fast though, I've beaten g35s and SRT-4s pretty easily (they look very suprised
![Wink](https://www.rx8club.com/images/smilies/wink.gif)
Last edited by staticlag; 09-29-2006 at 04:05 PM.
#39
Dyno'ed my manual at 155 whp ....6 speed =)...we'll claim it was more because it was a mustang dyno ((though I think I got the fat kid Ren))......thank god its being replaced as we talk in the recall =)
#41
Listen to Zoom44
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Originally Posted by Skiptomylue
you needed the new engine???
i think we should get more people dynoing their car after they get the newest Flash.. see what they are putting out..
i think we should get more people dynoing their car after they get the newest Flash.. see what they are putting out..
#45
Dongbag extrordinare
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Originally Posted by spokenstone
I just went to the dealer. You don't need the recall letter.
#50
The Professor
Thread Starter
Originally Posted by rotary crazy
how about timig?