Horrible 1/4 mile time with 99 cobra! :s

[MethosSVT]

Hello my friends ! well I went to the track with a 99 cobra convertible(bought it a couple of months ago) and I got beaten by absolutely everything I raced, my best time was 14.2 at 101mph. I did 7 passes and all of them where 14.2 at 101 mph. I am very dissapointed but I wanted to check with you guys to see what the problem can be or if those times aren't as bad as I'm thinking they are. Here is the list of my mods and other info: JLT CAI, O/R H-pipe, diablo sport tune, 245/17 tires all around, new E3 plugs, and last owner told me that the car had the engine rebuilt but he had no proof of it so I bought it as a stock car basically. It also seems like the recall was done to it because it has a green dot on the manifold. thanks everyone for any input and help !
p.s. one issue I have with the car is that it shuts down when I do harsh compression when coming to a stop. RMP'S just drop down really low and it dies once I come to a stop. Also the car stops pulling after 6000 rpm, I know peak HP is around that area but I feel like it really dies after that.
UPDATE - I think that shifting at 6900 - 7000 rmp was one of the problems, I've been reading that low 6k's would help a lot

 

[DarkMach1]

Looks like drag radials and line lock(if you're not good at doing good 2nd gear burnouts) should be your next mods. Launch at 4500 and come back to discuss your new times.

 

[SuperMarioSVT]

Thats about what mine would run when it had just a cat back, gear, intake. springs, shocks and a tune. I would suggest wider rims/stickier tires, and stiffen up the rear end with a stop the hop brace.

My car also drops below idle when i come to stops (usually when i push in the clutch at higher rpm's and hit the brakes). Happened after it got tuned. Doesn't do it all of the time though. What i do to control it is rev match on down shifts when i come to stops. I also cleaned my air filter and that helped dramatically. You can also try changing your low idle control sensor/module and see if that helps, but i doubt it.

 

[StngStr]

What was the DA? What were your 60 fts? Low 14's/high 13's are 99-04 GT times.

 

[SVTPete83]

My 99 cobra ran consistent 13.6's to a best of 13.20 stock. Mph was always around 105-6

 

[Brutal Metal]

Looks like drag radials and line lock(if you're not good at doing good 2nd gear burnouts) should be Launch at 4500 and come back to discuss your new times.

No offense but this isn't great advice, launching at 4500 with DR's on those 28 spline half shafts without an IRS diff brace or Delrin bushings is asking for carnage!

 

[SuperMarioSVT]

No offense but this isn't great advice, launching at 4500 with DR's on those 28 spline half shafts without an IRS diff brace or Delrin bushings is asking for carnage!

+1 something is bound to snap. Should def. slip the clutch out at around 2500-3000RPM's

 

[Crushinator]

Your times could be improved a tad with some practice. Typical '99 Cobra's
are high 13/low 14 second cars. Practice and you'll get it in the '13's.

 

[MethosSVT]

What was the DA? What were your 60 fts? Low 14's/high 13's are 99-04 GT times.

*0.35 -0.36 reaction time(I need to work a bit on that, it was my first time at that track and my first time racing this car, i had never launched it from 0 before)
*2.37 60 ft
*9.29 1/8 ET at 80.29
*14.21 1/4 ET at 101.12

I had to launch at about 1500 rmp and slowly press the gas to avoid wheel hop. Tried launching harder one pass and had to let off to avoid braking the halfshafts. I do know better tires will help but given the fact that stock tires are 245's, I thought I would get at least in the high 13's with those bolt-ons, I even got beaten by a cobra clone haha

 

[MethosSVT]

No offense but this isn't great advice, launching at 4500 with DR's on those 28 spline half shafts without an IRS diff brace or Delrin bushings is asking for carnage!

Agree, without aftermarket halfshafts and bushings all around the IRS I would be lucky if I get to drive it back home after a few passes haha around 2900 sounds better with some sticky tires(which I don't have yet haha)

 

[TBCobra]

Reaction time does not count towards your ET so take your time off the launch.

Your 60ft is killing you. I have pulled 2.0 60ft on street tires.

If you are launching low my guess is you're bogging and with 3.27's its taking a long time to get back into your powerband causing your slow 1/8th mile times.

Either get some better tires and/or 4.10's-4.30's and you will hit low 13's.

 

[MethosSVT]

My 99 cobra ran consistent 13.6's to a best of 13.20 stock. Mph was always around 105-6

yeah I've heard a lot of mid 13's stock, mine being a vert I was hoping for high 13's. I've been cheking the engine for weird things, it does seems like it had an engine rebuild. I'm hoping that the guy didn't **** anything up on it. He told me that the car had cams and supporting mods plus it was bored but I think he was BSing me, I think it just had some gaskets replaced and that's it. Another crazy idea of mine is that if the engine was actually rebuilt, the tune from the diablo sport is not working very well with those settings, thus making the car slower and making it shut off when compressing. I don't know I'm just talking crap right now because I'm desperated :S haha

 

[bad02svt]

seems like your doing something wrong my 2000 2v gt just with diablo sport tuner maxxed out x pipe intake and flowmasters ran 13.5 @ 99mph on stock gears 327's i beleive

 

[Brutal Metal]

Your times could be improved a tad with some practice. Typical '99 Cobra's
are high 13/low 14 second cars. Practice and you'll get it in the '13's.

Typical 99 cobra's run slower than stock Fox bodies? low 14's? whose driving grandma?:shrug:

 

[SVTPete83]

yeah I've heard a lot of mid 13's stock, mine being a vert I was hoping for high 13's. I've been cheking the engine for weird things, it does seems like it had an engine rebuild. I'm hoping that the guy didn't **** anything up on it. He told me that the car had cams and supporting mods plus it was bored but I think he was BSing me, I think it just had some gaskets replaced and that's it. Another crazy idea of mine is that if the engine was actually rebuilt, the tune from the diablo sport is not working very well with those settings, thus making the car slower and making it shut off when compressing. I don't know I'm just talking crap right now because I'm desperated :S haha

When buying a car with a tune the first thing I do is take it to my tuner and have him redo it. I only trust my tuner. That being said you have a 13 second car you're just not drivin it yet. To get my car deep into the 13's it took a lot of clutch slip and aggressive launches. With stock tires you prob won't bust an axle but I say probably... Meaning there is a chance. I was launching mine at 3k and slipping the clutch until the 60 ft mark or so to get the best 60 foots. Remember. A tenth in sixty is usually 2-3 tenths off your et. Get into the 2.0-2.1 range and you will see your 13's. Your mph and weight indicates a 260 rwhp car. Is your tune off? Possibly. My 99 stock post fix out down 282. Just some food for thought.

 

[StngStr]

yep....get that 60 ft down to 2.0 and you'll be in the mid-high 13's all day long.

 

[MethosSVT]

When buying a car with a tune the first thing I do is take it to my tuner and have him redo it. I only trust my tuner. That being said you have a 13 second car you're just not drivin it yet. To get my car deep into the 13's it took a lot of clutch slip and aggressive launches. With stock tires you prob won't bust an axle but I say probably... Meaning there is a chance. I was launching mine at 3k and slipping the clutch until the 60 ft mark or so to get the best 60 foots. Remember. A tenth in sixty is usually 2-3 tenths off your et. Get into the 2.0-2.1 range and you will see your 13's. Your mph and weight indicates a 260 rwhp car. Is your tune off? Possibly. My 99 stock post fix out down 282. Just some food for thought.

Well is not that I'm driving terribly bad, the tires just won't let me launch over 1800 rmp, and 1800 would be almost asking for wheel hop. The tuner is a diablo sport that can be used for any 99 - 04 4.6 v8, to me that was very weird given that 2v's and 4v's are so different, I contacted diablo sport and asked if the same tune would work both on a gt and a cobra, and they just answered a quick "yes it works" I think the diablo sport adapts itself to the car you put it on because I checked my rev limiters and they were over 7k rmp ( on my GT they where at 6200 or something like that)

p.s. I don't know if this info helps but, I get wheel hop even when launching from a roll and gradually depressing the gas

 

[MethosSVT]

Typical 99 cobra's run slower than stock Fox bodies? low 14's? whose driving grandma?:shrug:

yeah, 99 cobras shouldn't be in the 14's in my opinion, hell my GT runs faster times :S kind of ironic because I can feel the cobra has more power, I'm so frustrated with the car right now

 

[Kiohtee]

Well OP, you have plenty of sound advice to follow up on so just make sure to listen to these guys and with time you will be very happy with your accomplishments.

 

[MethosSVT]

Well OP, you have plenty of sound advice to follow up on so just make sure to listen to these guys and with time you will be very happy with your accomplishments.

yup, I'll try with the tires first, still I think there is some sort of mechanical issue with the car, but well I'll try to get that figured out and then come back.

P.S. thanks everyone for taking the time to answer the post !