It seems to me that you turning WAY too many RPM's for a basically stock motor. Have you had the car on a dyno to see what the power band looks like?
Where to go from here.
Ok guys I have been greatly disapointed by my track times lately Iam not sure if it is me or something with the car I need to look at.
Iam running a 1996 cobra. I have 4:10 gears, K and N fipk ford raceing alum drive shaft, Summit brand upper and lower control arms, mac pro chamber H pype also running the new Nitto nt05r's 275/45/17's this week end and I do have a tuner with custom tunes from american muscle. I went to the track this weekend and with the custom tune the best I could hit was a 14.5 and I ran this 3 times. I then retuned it to stock and was able to get it down to a 14.1 trapping at 98.45. I felt like I was getting good traction off the line but my 60 foot time was 2.05. The car seems to run good but this is the best time I could get out of her. Iam shift at 6900 and launching around 3500. I have cleaned my IRMC's and changed the plugs and wires. Were should I go from here to help my quater mile times? What mods should I be looking into? I have read many times that the cobras running low 13's with gears but I cant even break into the 13's with it. Any help would be awesome.
Iam running a 1996 cobra. I have 4:10 gears, K and N fipk ford raceing alum drive shaft, Summit brand upper and lower control arms, mac pro chamber H pype also running the new Nitto nt05r's 275/45/17's this week end and I do have a tuner with custom tunes from american muscle. I went to the track this weekend and with the custom tune the best I could hit was a 14.5 and I ran this 3 times. I then retuned it to stock and was able to get it down to a 14.1 trapping at 98.45. I felt like I was getting good traction off the line but my 60 foot time was 2.05. The car seems to run good but this is the best time I could get out of her. Iam shift at 6900 and launching around 3500. I have cleaned my IRMC's and changed the plugs and wires. Were should I go from here to help my quater mile times? What mods should I be looking into? I have read many times that the cobras running low 13's with gears but I cant even break into the 13's with it. Any help would be awesome.
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G
the problem lies at shifting a 6900 rpm....
you are so out of the powerband......
you are so out of the powerband......
I thought the 4.6l DOHC loved the high rpms? What should i be shifting at?
Ill have to give that a try next time out. I was shifting around that before and was running what Iam running with drag slicks so that would make sense because I picked up some time with the drag slicks but lost time because I shifted higher. Any other advise or other mods I should look into. My orginal goal for this car was a 13.25 on motor. I just purchased a 90 5.0 to start working on in the next couple months and would like to hit that 13.25 mark with the cobra before I start modding my 5.0.
I just found another thread that backs up shifting at that RPM. If iam understanding it right you should shift 10% above the max power. So on a 96 cobra the max power was at 5800. This puts the shift point some where around 6380. Thanks for bringing that up it got me searching in the right direction I think.
I just found another thread that backs up shifting at that RPM. If iam understanding it right you should shift 10% above the max power. So on a 96 cobra the max power was at 5800. This puts the shift point some where around 6380. Thanks for bringing that up it got me searching in the right direction I think.
G
I just found another thread that backs up shifting at that RPM. If iam understanding it right you should shift 10% above the max power. So on a 96 cobra the max power was at 5800. This puts the shift point some where around 6380. Thanks for bringing that up it got me searching in the right direction I think.
for the sake of conversation we will use 5000 rpm as maximum power.....
based on your reading that would put your shift point at 5500.....
if you look at a dyno sheet with is usally a bell curve graph....
there will a percentage of drop off at the top of the curve....
so by shifting at 5500 you will be outside of the powerband
the engine is producing less power which equals less acceleration......
so what would be the point of shifting 10% higher.......
By doing so the results will be lower E/T's......
From the way the post read you should shift at 10% higher because you are still making more power at that mark (Say 5500) than you would make at the lower RPM you will hit by shifting. I guess the only true way to know shift points would be to have it dynoed and get the HP at each RPM and than look to see were it is most efficient to shift. I now know that 6900 is for sure to high.
G
No guessing about its the only way to really know......From the way the post read you should shift at 10% higher because you are still making more power at that mark (Say 5500) than you would make at the lower RPM you will hit by shifting. I guess the only true way to know shift points would be to have it dynoed and get the HP at each RPM and than look to see were it is most efficient to shift. I now know that 6900 is for sure to high.
Sounds like the tune may need some tweaking. I would call AM and talk to Chris Rose about it also. Your tires are another weakness. You need some good sticky tires. As mentioned shifting,you will figure that out also.
I like to use a test and tune day and the 1320 dyno to figure out shift points. I start at an rpm I'm pretty sure is too low then go up 200 rpm each pass till I see the mph start to drop off, then back down a little till I find the highest trap speed.
The highest trap speed should indicate maximum power. How you harness that power is a different ball game!
The highest trap speed should indicate maximum power. How you harness that power is a different ball game!
I have to agree with Bkid......
If you loaded the stock tune back in and it performed better given the same parameters, it is in the tune. We hate canned tunes.......
Strap it on the rollers, and find where your power curve is once you get the tune fixed.....
If you loaded the stock tune back in and it performed better given the same parameters, it is in the tune. We hate canned tunes.......
Strap it on the rollers, and find where your power curve is once you get the tune fixed.....
Iam hoping to get a new tune from American muscle this week. The ones i have were before they were using bama for tuning so I will go though and see about getting a new tune and make it back to the track not this Friday but the Friday after that. Iam going to get it dynoed once I find someone in this area to do it. I think I might have to make the 2 hour drive to KC.
G
+1...........I have to agree with Bkid......
If you loaded the stock tune back in and it performed better given the same parameters, it is in the tune. We hate canned tunes.......
Strap it on the rollers, and find where your power curve is once you get the tune fixed.....
A canned tune is like wearing an off the rack suit it never fits just right......
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