Dyno'd my car. WTF?

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Phantom959

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Dec 14, 2000
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#1
2004 GT(Black 5m)Predator tuned,VT STage 2 cams, BBK SHorty' TFS Plenum(Black),Accufab 75MMTB, Steeda Pulleys, JLT Cold Air, 4.10's, U/L control arms, UPR Offy X-Pipe, Spintech's with MagnaFlow 3.5 tips, 10.5 Deep Dish Bullets on back with 315/35 Nittos, Maxspeed 1.5 Springs,Pro5.0 Shifter, Mustang world side scoop inserts, V-6 Hood.
Thats my mods, dyno'd it back in March & got 259/299. Dyno'd today & best is
260/281. Dyno guy kept the car in 3rd. I have added the cams/headers since the March dyno. Somehow I gained 1 HP & lost 18 torque. :(
 

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#3
yeah that predator tune is crap. Get a real tune, SCT tune. Look how lean your are running also. Those shorty headers arent helping your car too much.

Is the dyno a dynojet or mustang dyno?
 
#5
It is a dynojet. I knew the tune was going to be off b4 the dyno. ONly reason I went was to get the A/F & MAF Voltage so I could get it dialed in. I was about to cry when I saw the #'s. I have been told by several people that the car should have been in 4th gear not 3rd.
 
#6
Phantom959 said:
It is a dynojet. I knew the tune was going to be off b4 the dyno. ONly reason I went was to get the A/F & MAF Voltage so I could get it dialed in. I was about to cry when I saw the #'s. I have been told by several people that the car should have been in 4th gear not 3rd.
Click to expand...

They are correct numbers are low because you did the run in 3rd gear. As far as needing a tune, it wouldn't hurt, but it doesn't look like the current one is killing you either. Get the MAF dialed in and you should be fine.
 
#7
Phantom959 said:
2004 GT(Black 5m)Predator tuned,VT STage 2 cams, BBK SHorty' TFS Plenum(Black),Accufab 75MMTB, Steeda Pulleys, JLT Cold Air, 4.10's, U/L control arms, UPR Offy X-Pipe, Spintech's with MagnaFlow 3.5 tips, 10.5 Deep Dish Bullets on back with 315/35 Nittos, Maxspeed 1.5 Springs,Pro5.0 Shifter, Mustang world side scoop inserts, V-6 Hood.
Thats my mods, dyno'd it back in March & got 259/299. Dyno'd today & best is
260/281. Dyno guy kept the car in 3rd. I have added the cams/headers since the March dyno. Somehow I gained 1 HP & lost 18 torque. :(
Click to expand...
Several isues:

1. don't read too much into dyno numbers. If the car is running fine then don't worry.

2. A good tune should really be done after each mod unless you are doing another one immediatley.

3. To get a so called accurate reading from a rolling road your car needs to be dyno'd in whater ever gear is as close to a 1:1 ratio. With a stang 4th for a manual or auto should actually be 1:1 if anyother gear is used it will dramtically distort the numbers. The car can of course still be tuned as the profile of the torque curve on the graph will be correct, just in the wrong place.

Remember bhp is a calculation of lb ft and the rollers rpm of the dyno. So at 5000rpm in 3rd the rollers will be rotating slower than they would be in 4th.
 
#9
300bhp/ton said:
2. A good tune should really be done after each mod unless you are doing another one immediatley.
Click to expand...

This is a myth. If the MAF is properly dialed in the first time there are very few mods that acutally require a re-tune, unless you are talking about those that require actual scalar changes such as changing injectors, gears, turning off rear o2's etc.
 
#10
Phantom959 said:
It is a dynojet. I knew the tune was going to be off b4 the dyno. ONly reason I went was to get the A/F & MAF Voltage so I could get it dialed in. I was about to cry when I saw the #'s. I have been told by several people that the car should have been in 4th gear not 3rd.
Click to expand...
They did your run in 3rd? You have a manual or auto? If the place did your run in 3rd in a manual then they dont have a clue what they are doing and I would recommend taking it to another place.

You are also running really lean, I would be careful with running that 15 a/f ratio and having it going only to 13 a/f ration. It should be between 13.5-13.5 across the page.
 
#12
mogs01gt said:
You are also running really lean, I would be careful with running that 15 a/f ratio and having it going only to 13 a/f ration. It should be between 13.5-13.5 across the page.
Click to expand...

Without knowing the load percentage or MAF voltage you can't really say that for sure. After tip-in he runs about 14.7 (stoich) until he gets into the higher rpms. Depending on what load or VE he as at until 4k or so, this may be normal.
 
#14
drew_shipley said:
Yeah, the whole keeping it in 3rd is your main problem. You do also need a tune. Get it dyno tuned at another place that knows what they're doing.
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Yep it was only in 3rd, it only went up to about 90 b3 redlining. I got the tune from injectedracing.com b4 the headers so that is why it is out of whack...

Alternative Motorsports is where it was dyno'd.
 
#17
Yeah. Those numbers do seem low... I could have sworn I saw someone posting dynos for those cams and similar mods a while back and they were making 300-320, but I could be wrong. I want to say they made close to 280 or so with just the cams and stock headers + heads.
 
#18
You need to get it tuned to Fourth because of your manual. Most if not all of the calculations the dyno computer makes are based on the rear gear and the 1:1 gear ratio to know what the engine is turning. You may have more power than you think and more over the a/f ratio is high I wouldn't be driving around with that too long.

Good Luck man :nice: :flag:
 
#19
a tune prolly wont gain you too much, but should do for a/f reasons. the car was plain and simple dynoed in the wrong gear. might as well throw the dyno print out in the trash, cause its no good. get it redynoed.
 
#20
the headers are not gonna do much for you anyway...but for sure it sounds like the cam is too much without a custom tune cause you are for sure losing some power somewhere...
 
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