So, we had a dyno day in my club. Some people had the issue of a LARGE hp loss there (for example; a car dynoed there had 100 hp more with the other owner.. before the high-flow cat install and it was dynoed at the same place [they even pulled it off the computer]); and I was wondering a few things.
They use 20% drivetrain loss (as told to me by the owner) and after my mods I ran a peak of 228.7hp. Later when I was leaving, I hopped in the car, started it up and realized that he left the vent in the on position in the car. Another thing is that I think I may have 3.55's but I'm not a 100% sure.
The reason I have questions is because I've looked on the net and seen that some stock gts are running what I'm running apparently. Could any of those lowered my numbers?
Thanks
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Current Mods: 3.55 gears(?), C&L Plenum, 70mm TB, white face gauges, LCAs and Sub-frames (waiting), JLT RAI, Mac Catback
Mods up next: Mid-length headers, mid-pipe
Mods in the near future: Heads, internals, and misc. engine things.
Mods in far future: Complete new suspension, new wheels, and complete body repaint and repair(to fix the dings of daily driving)... and then make her a weekend only car.
Okay, so I now know the A/C disengages at WOT (as two people have told me). So... there are only four possibilities and I'd like anything someone smarter than me (there's a wide range of people) has to help me figure this out; if at all possible.
1) Either I'm running lean or rich
2) They aren't making too much of a diff. because of stock exhaust
3) I have 3.55 gears (I used your tech calculator).
4) I'm paranoid and shouldn't worry and/or my car was made on a bad day.
I just question because someone there had a stock GT pull 2 hp less than me.
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Current Mods: 3.55 gears(?), C&L Plenum, 70mm TB, white face gauges, LCAs and Sub-frames (waiting), JLT RAI, Mac Catback
Mods up next: Mid-length headers, mid-pipe
Mods in the near future: Heads, internals, and misc. engine things.
Mods in far future: Complete new suspension, new wheels, and complete body repaint and repair(to fix the dings of daily driving)... and then make her a weekend only car.
Last edited by Green_Hornet; 08-22-2004 at 05:21 PM.
Reason: darn that spelling
Current Mods: 3.55 gears(?), C&L Plenum, 70mm TB, white face gauges, LCAs and Sub-frames (waiting), JLT RAI, Mac Catback
Mods up next: Mid-length headers, mid-pipe
Mods in the near future: Heads, internals, and misc. engine things.
Mods in far future: Complete new suspension, new wheels, and complete body repaint and repair(to fix the dings of daily driving)... and then make her a weekend only car.
SAE numbers are going to be lower then STD. Gears don't really make that big of difference. The more gear you have, the less power it's going to show. With 3.55's it's not going to make a huge difference maybe just a few HP at the most. The dyno doesn't care what gear you have. It basically uses torque and RPM to figure out how much power you are making.
those dyno numbers are in line with the ones around here with similiar mods. Was your engine hot or cold for the runs? The gears will not effect the dyno results, people have proven this in other threads here on AFM.
Now Stock GT's will dyno around here at around 219-221 rwhp and from what i see you have a MAC CAI...not worth much, a C&L plenum and a 70mm tb. and stock exhaust. get either a off-road h or x pipe or one with high flow cats. our stock h-pipes are very restrictive. you have increased one side of the equation... remember AIR PUMP. when you improve the air flow in you need to improve the air flow out also or your intake mods may not be funtionaing to their potential. Also mods hpincreases work in conjunction with each other and are not just added together. so when C&L advertises 14 hp is that at the flywheel or tires? mac advertises 10 hp same question here and the 70mm tb is suppose to give you 8 hp. but you just can't expect to add the 14, 10 and 8 together and see those results on a dyno. it's how everything works together not individually. You have about 7-9 hp increase with those mods which is about normal.
Glad someone else pointed out what I thought from jump .... sounds about normal even with the modest mods you've put on the car.
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"I've been around long enough to know how ignorant I am. I don't assume the universe obeys my preconceptions. Hah! But I know a frelling fact when it hits me in the face." -Rygel
My ROUSH Rides
98 ROUSH Stage 2 GT
03 ROUSH Cobra
Meh, I figured I needed exhaust mods... I'm just too hopeful (that and I'm pretty slow. Sucks lol). Thanks for all the input peeps.
*goes and checks account then searches for x and h pipes*
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Current Mods: 3.55 gears(?), C&L Plenum, 70mm TB, white face gauges, LCAs and Sub-frames (waiting), JLT RAI, Mac Catback
Mods up next: Mid-length headers, mid-pipe
Mods in the near future: Heads, internals, and misc. engine things.
Mods in far future: Complete new suspension, new wheels, and complete body repaint and repair(to fix the dings of daily driving)... and then make her a weekend only car.
The gear thing, it is my understanding that it is not much of a factor. I am use to race cars, so a 10hp loss or gain on 1000hp car is not noticed. But I might feel different when I bring my Cobra in for a dyno run . We always hope for more. Some ppl just seem to get real good running cars and do better then average (never me).
If you want to find out for sure what your gear ratio is, there is a way to find it out. by putting the car in neutral and having the rear up on jack stands. Count the number of rotations of the wheel, vs. the number of rotations of the drive shaft. This will tell you what your ratio is.
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-1998 Black Cobra, Kenne Bell 2.1L Supercharged
-2005 Mustang GT, Premium, 5spd, Redfire, Mac Catback
-2007 Roush Nitemare Stage 3 Supercharged #48 of 100
Dyno Today -- Have Questions 
. We always hope for more. Some ppl just seem to get real good running cars and do better then average (never me).
