See Also Ross's Page
for many more dyno charts....
Check out This Page for info on dynos and dyno testing.
The originals were in color. I scanned in black and white gray scale to get smaller file sizes, then used gamma correction to increase the contrast. I may redo the graphs to try to emphasize the color differences. The colors coded the different runs for the same test, and the results are pretty consistent between runs so you are not missing much.
Each chart is about 50K. Images are the property of Tammy ( Siochain11@aol.com ) or Rich so get her permission first if you want to copy the images.
See Tammy's car in the Gallery.
Done at Lee's Performance Center in Charlotte, NC.
When I look at the graphs of my dyno runs, everything is going great until 5000 rpms, when all power is lost. The downward slope is twice the magnitude of the gain before 5000 rpms. Lee told me that when the engine is chugging along that fast, you really need to open up the flow ability. He said that headers would do that. Looking at Ntruder's power above 5000 rpms, his seems to drop off with the same slope. The little info above 5000 rpms on tammy's plots seem to offer a shallower slope however.
Any ideas on that? (jsut to note - at 2000 rpms I have the same amount of torque that I do at 6000 rpms)
We ran with the hood closed also. Lost 4 hp/ft-lbs across the ENTIRE range. Solution he said was to simply stick the filter in the airflow. Even with the hood open, it was still sucking in hot air, because the bottom half of the filter wasn't exposed to fresh air. He guessed that I'd pick up an additional 5 hp just by sticking the entire filter into the fresh air stream. Enter Ross's sucess with the Hotshot intake.
I remember that Felipe said that he agreed with William's letter to SCC (regarding heat conductance in the intake tract). The basic premise was that a hot intake tract would heat up the air flowing through it. I agreed with Felipe and William, but not any more. Lee said that on the Winston Cup cars, the temp of the intake plumbing didn't really matter one bit. As soon as the filter sucked in the fresh air, then the intake air temp was back to ambient... even if those V8s were running at 1,000,000 degrees. So - make it metal, plastic, whatever. It doesn't matter. So a metal Hotshot intake won't be worse than a plastic one. He did comment on the "iceman" types. He said he didn't like them, since they were so low. But he understood that we don't have a hood scoop to play with. However, he said in his experience, routing air to a filter placed close to the airflow was better than sticking the filter in the airflow. Maybe I should run tubing from right in front of the radiator.
Other things he said would work: - cat pipe (William picked up 5 hp throughout with this) - new fuel system for high rpm usage (stock is sometimes not good enough at high rpms) - porting the heads - enables more flow above 5000 rpms, but possibly at a loss under 3000... - new cam profile - nitrous, turbo, etc.
I'm most concerned about the drop after 5000 rpms. It's like the engine just turns off... like wasted rpm range. Now that I've got the pulley, the accessories are safer in that range. Maybe it's just a "safely" ploy on the part of Mazda by giving us cams that die at 5k?
Last last thing: during one of the warm up runs I stood outside the building, and listened to the exhaust (never get to do that!!). Well, above 5000 rpms, it really screamed LOUD. And the funny thing was, there was this black smoke that came occasionally, shooting about 40 feet back or so. Like small bullets. At an incredible speed. Was the car running rich to generate this black exhaust?? Is this one of the problems of loosing the punch above 5000 rpms?
Jan99 - Those of us that have G-Tech Pro accelerometers have probably measured the HP of of our cars. The only problem is that the HP readings are affected by wind resistance. How can we relate the number back to wheel HP, you ask?
If you look at the October 98 issue of SCC, they "dyno" a '97 probe using a Vericom accelerometer and a Dynojet. The Vericom test was done in 2nd gear, the same way most of us use the G-Tech to measure HP.
Assuming more or less constant conditions, we can correlate the peak Dynojet HP of 146 (see pg 120) to the peak Vericom HP of 127 (see pg 118). Note that a PRM intake was used in the test, so the Vericom HP might actually be a little high (ram air effect, cold air, etc). It might be better then to compare the PRM-Intake-Dynojet number (146) with the stock Vericom HP number (124).
My HP numbers in 2nd gear (22C, nice day) show about 124HP, so my numbers are in line with the Vericom. (thanks to MP)
A site with lots of dyno runs for different cars. The site is: http://www.zim.com/maxperf/dynor.htm
23Dec98 Justin HS/GReddy/NOS Dyno1
This is not conclusive that my intake ADDED hp, but shows I prolly am not LOSING any either...
Trenton HS/Borla/Brospeed Headers
Darin Custom C/A; Greddy; Lightened FW/ACT Stage II
The temp was about 47 Degrees F, the Vapor Press was .53 The Baro was 30.27. All figures should be adjusted by the correction factor 0.97 (Thanks to DP)
FYI, here are some DynoJet numbers from a recent dyno day at work. Check out the 400 ft-lb shot NOS numbers! This is the competition around Dearborn! 28Oct98
VEHICLE H.P. TORQUE
'94 Toyota Supra 314.7 315.2
'93 Mustang N/A 308.7 335.7
'89 Mustang N/A 310.8 338.5
'93 Mustang GT S/C 420.0 438.8
'94 Mustang N/A 286.0 315.0
'95 Cobra S/C 397.8 415.2
'87 Mustang LX S/C 365.0 364.6
'96 Mustang GT S/C 565.3 529.2 4.6 2v!
'91 Mustang S/C 360.0 412.4
'97 Cobra N/A 264.2 271.5
'90 Mustang LX S/C 400.5 426.0
'95 Cobra N/A 262.0 282.3
'78 Datson 280Z T/C 370.6 400.2
'95 Mustang N/A 293.0 329.0
'88 Mustang S/C 548.3 506.6 Finally!
'69 Mustang N/A 273.4 342.3
'93 Mustang N/A 301.7 336.7
'94 Cobra S/C 443.1 477.2
'85 Mustang N/A 322.0 308.0
Well Tuned '90 Mustang 435.0 486.3 NOS 649.4 730.8
'91 Mustang 458.1 400.1 NOS 648.0 772.3
'83 Ranger 190.9 234.4 NOS 378.7 624.1
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