I am thinking about having some dyno work done on my GT as part of a custom tune. For those of you that have done this, can you give me an idea of the cost range for custom tuning.
Thanks in advance.
Thanks in advance.
Dyno work
- Thread starter JimF
- Start date
Not the easiest question to answer. Simple answer is several hundred dollars assuming no equipment is required. It will take one of two pulls to set a baseline, if no problem. Than several pulls to tune the car as adjustments are made and/or faulty parts are changed or corrected.
Depends upon what issues, if any exist on a given car. Some have no problems, others have several problems that need to be resolved before tuning can be accomplished. For example if spark plugs are too hot or cold they need to be changed. Air/Fuel ratio needs to be monitored and changed as required. Many other performance parameters such as RWHP, torque, RPM, spark advance, boost leevls and when you want boost to come in and at what level, EGT, IAT, CHT, ECM O2, TPS, need to be constantly monitored. If shop has an off-the-shelf tune, run as fast as you can, IMO. If they don't fix prolems you seelcted the wrong shop.
Yes I have seen problems with GTs. No two are the same.
Pick your dyno shop wisely and ask for previous before and after dyno sheets on a similar vehicle and speak to the vehicle'siowner. Watch out for gamesmenship relating to not using maximum smoothing and not using a corrcetion factor to inflate results. Not using max smoothing skews results as a spike in the graph will be taken as the max reading and does not accurately reflect real results.
Good dyno hunting
:cheers
Fubar
Totally ****** Up
All of the above is good advice. I would like to add that choosing a Dyno that is capable of handling cars like the GT is no small part of the equation. You need a machine that can add resistance and adjust for speed (as the GT is a 200+ mph car). Make sure your shop has the latest Dyno equipment AND knows how to use it.
Let us know what you get. Heffner's pully and tune worked well for me.
Let us know what you get. Heffner's pully and tune worked well for me.
Fubar
Totally ****** Up
You are right and for simply measuring HP that is fine but if you are going to actually TUNE the car you need a machine that can compensate for wind resistance. If you don't have that you will get a tune that is to lean for street use.
Any tuner worth his salt knows this and can compensate but because the GT is so aerodynamic the tuner my over compensate. It is better to simply type in the car drag coefficient and let the computer do the calculations. The newer machines can add resistance (drag) as you approach speeds of say 150, 160 etc and let you tune the car more accurately.
At least that is what I have been told. I am not a tuner and I don't own a dyno. So take it for what it is worth. I have had several cars tuned and looked at tuning the GT but could not find a tuner that I trusted in the area. Heffner's experience with high speed cars made the choice easy for me.
:thumbsup
cobrar1339
GT Owner
Fubar,
The AF on the graph looks a little leaner than what I have noticed on some other pulley tunes. Do you know where they picked up the AF from? ( Pipe or 02 bung), any tweeking on it or is that a 93 octane tune?. Just curious
Very nice results.
The AF on the graph looks a little leaner than what I have noticed on some other pulley tunes. Do you know where they picked up the AF from? ( Pipe or 02 bung), any tweeking on it or is that a 93 octane tune?. Just curious
Very nice results.
Fubar,
Unless your car was tuned on another dyno, the Dynojet curves you posted were generated on a machine that cannot vary load as you described. Furthermore, relying on a "mail order tune," even from a reputable forum vendor, may be safe, but not necessary optimal. The last GT I saw dyno'd with a mail order pulley/tune was pig rich, ie <10:1. Picked up another 25 rwhp by leaning it out to 12.5:1 on a Dynojet, which allows plenty of margin for real world issues like wind resistance.
My buddy Corey Henderson has a state of the art load bearing Dyno Dynamics all wheel dyno in addition to the ubiquitous Dynojet. His shop, Henderson Performance Technologies, in New Braunfels, will be tuning my soon to be Whippled car.
Fubar
Totally ****** Up
Again, I do not own a Dyno machine but have done some research on it. Dyno-dynamic used to have the market on high speed resistance and a year ago I would have agreed with you 100%. However the new Dyno-Jet machine have added the technology necessary to "speed tune." I was not tuning tho, I only wanted to make sure my new car was performing as expected. Dyno-Jets also produce HP numbers that are 10-15% higher than Dyno Dynamic, that is all BS to a tuner... change is the only thing to look at but for bragging rights you want a pull on a Dyno-Jet.
DoctorV8 said:
That was the reason for this pull, just to make sure the numbers looked good. It felt pretty good by the seat-of-my-pants Dyno but I wanted the real numbers. So the Heffner tune seemed to be spot on for this car.
cobra1339 said:
They took the A/F from the tail pipes (not the best place to get it but this was a quick and dirty power test).
Fubar
Totally ****** Up
This was a really good thread we did on some of the different results you get on the two machines.
http://www.fordgtforum.com/forums/showthread.php?t=4980
(I had to go through and update the picture locations :biggrin )
http://www.fordgtforum.com/forums/showthread.php?t=4980
(I had to go through and update the picture locations :biggrin )
A GT has a cD of approximately .40 which is not that aero. A C5 Vette, non-Z06, has a cD of .29. The new LS460 Lexus (yes the big 4 door sedan) has a cD of .26.
:cheers
Dave
BlackICE
GT Owner
BlackICE
GT Owner
I found this post on frontal area
Quote:
Originally Posted by californiacuda
I have carefully measured my GT and come up with 19.95 sq ft of frontal area. Using this number and the air resistance number of 874 lbs at 200mphf rom a magazine article previously mentioned in this forum and estimating the rolling resistance at around 100lbs, I came up with a drag coefficient of .388.
I think you are very close with the Cd. The most Ford has said was "under .39". I believe the frontal is ~19.2 - 19.5 sq ft.
http://www.fordgtforum.com/forums/showpost.php?p=14475&postcount=11
Fubar
Totally ****** Up
Wow that is impressive. I wonder why the discrepancy? What kind of cD do race cars usually contend with?
found this http://en.wikipedia.org/wiki/Automobile_drag_coefficients
nice list of cars to look at.
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Some companies demand better aero than others for many reasons. What looks sleek is not always sleek.
If you read "All Corvettes are Red" it describes the design porcess of the C5 and a goal was equalling the lowest cd production car in the world at that time, the LS400 Lexus which was at .30 The lower the drag the better the gas mileage is another design consideration. Helps with the fleet aveerages.
My C5 Z06 (less aero than the non Z06 shape) easily gets 28/29 mpg on trips avereaging 75 mph. My LS400 1998 only gets 26-28 mph at the same speed. This is driving in the Northeast with real hills not on flat roads.
Also adhering to a several decades old design shape was not the best way to go if you wanted lower aerodynamic drag. But that was another trade off if you wanted the GT to look like its heritage.
:cheers
Dave
satx
Well-known member
and Cd is not the end all of "sleek". Hence the GTs ability to do 212 (without the limiter) with ~510rwhp.
BlackICE
GT Owner
That is because in spite of the high CD it has a smaller cross section than most cars, together it isn't that bad. Now, if the same engine and chassis was optimized for a low drage the car would go even faster. However it would look much different that the 60's GT40.
Fubar
Totally ****** Up
I'm an getting a little confussed so help me with cD v/s cross section? I thought the cD was a function of the cross section.
Normally I try to stay out of these dyno talks but, the CD of the car has no effect on dyno tuning. If the dyno is a load bearing dyno and all of the fuel and spark tables are mapped under all load points then you'll be fine. There is no need to take into account CD.
Michael
Michael
Dynos
I, for one, have learned more about dyno stuff from this thread. I want to have my car dyno tuned even more now.
I am in the So Cal area. Can anyone suggest great tuners in the area. I want to have the car tuned prior to the next Silver State Classic.
Thanks for the suggestions.
I, for one, have learned more about dyno stuff from this thread. I want to have my car dyno tuned even more now.
I am in the So Cal area. Can anyone suggest great tuners in the area. I want to have the car tuned prior to the next Silver State Classic.
Thanks for the suggestions.