Low mph in 1/4, any help?

91LX2Bfast · 10-21-2002, 05:33 PM

Car: '99 GT auto
Mods: Bassani o/r X, Flows, RFFperformance/DMann chip (from Stangnet if you don't know,) 80mm LMAF, 22C plugs.

Stock, the car turned a best 1/4 time in 14.22 @97.5 mph with me manual shfting it the first time out to the track. That was on a 2.08 60ft time.
Yesterday my brother gave me his car to take and run at the 15th Annual Fords at E-town and temp was also in the mid 50's with liitle to no wind and very low humidity. All day the car ran 14.1-14.2's between 97.2-97.8 mph with the mods. I am not worried about the ET because I was getting some tire spin off the line and 60ft times were 2.18-2.26 all day. It'll go 13's with traction, and I know the shift points are set perfectly because now manual shifting only slows the car.
What I don't understand is why the car didn't pick up any mph with the mods. The X-pipe alone is usually be worth 1mph, and the chip's functon of increased timing and locking up the TC, etc, should be wort another 1mph. I fully expected to be trapping around 99 - 99.5mph. There was another equally equiped auto GT with only exhaust, Diablochip, and aftermarket MAF trapping at 99.5-100mph, right where I think this car should be. And with the car giving a little spin off the line, that should only increase MPH slighty more, so I don't know what gives.
Any comments or suggestions?
We are going back to the track with the chip removed, stock plugs, and stock MAF to see what the car runs in that form. And then we'll throw the chip, colder plugs, and LMAF in and see what happends.
BTW, I ended up going to the finals and taking runner up in the Trophy Stock class

I broke out in the final by .033 At least the car is pretty consistant. But I can't be mad because I had a great time.

SleeperGT · 10-22-2002, 09:11 PM

91LX - Since nobody else has responded I'll throw my lame 2 cents in. I'm a little confused by your post. Are you comparing your car to your brothers car or comparing the same car? It sounds like the same car. Anyways, if your question boils down to comparing the same car it sounds like the issue is the car ran 97 mph stock and now with all your mods it still runs 97 mph. I could be wrong but most of the stock '99+ GT's I've seen at the track run low to mid 90 mph's. I know folks are going to get on and say they've seen stock '99's run upper 90's and even 100, but everytime I've been to the track that's what I've seen (then again I'm in FL and it has always been in the high 80's temperature wise). So if your car is one of the lucky stock ones which run upper 90's, then your mods (especially the chip upgrade) would be just an even swap possibly. From all I've read the '99+ cars have pretty decent exhaust systems, so unless your blowing or gassing your car the exhaust work won't get you too much (I'm sure it sounds faster though

!) I'm not sure what 22C plugs are, but I've never heard of a plug upgrade doing much for performance (actually measured at the track, not the butt dyno), unless the replaced plugs were shot. I would say if you put a SC or nitro on your car the exhaust and LMAF would help, but doing this just on a stock car might not help as much as you would think. Also was the chip programmed to handle the exhaust and LMAF? I made only three mods to my car and gained .4 seconds and 5 mph (LMAS and Anderson PowerPipe, and Diablo Chip), however the chip was specifically tuned for the other two mods (and my car is SC'ed). If the chips doesn't know about the mods you've done, you won't get as much gain. Well there's my 2 center of rambling and I'm sure it didn't help much. Your idea of running at the track back in stock configuration and then swapping the mods back on sounds like a good idea. I'm curious to here of the results, keep us posted and good luck with this.

91LX2Bfast · 10-22-2002, 10:33 PM

Well, all the 99+ GT's around here trap between 96-100mph stock, so maybe its an elevation thing.
I am comparing my borther's car's performance on two equally temp/humdity days. The chip was programmed with the LMAF and exhaust in mind. The 22C plugs are 1 step colder plugs to prevent detonation with the full advanced timing in the chip. Car runs 93 octane. Its proven that an o/r X-pipe is worth up to 20 HP at 6000rpm on a stock GT. Now thats not peak HP, but it's HP none the less. It should be worth almost 1 mph on a stock car.
ET has dropped, or at least will drop into the 13's with traction. But I am concerned with the MPH. Like I said, an equally equipped auto GT was running 99.5-100 mph all day with an exhaust, Diablochip, and MAF. So I know it wasn't the weather.

Dark_5.0 · 10-23-2002, 04:12 PM

Its weird how two of the exact same cars run different. I am at 3000ft of altitude and my cobra runs 100-102 mph in the 1/4 bone stock. No one else with a stock 99-01 cobra in my area can even hit 99mph much less 100.

Maybe its the driver. No offense.

Later,

91LX2Bfast · 10-23-2002, 08:52 PM

No offense taken. There's really no driver error to occur except on launch, and spinning would increae mph even more. I have logged a good number of passes down the 1/4 in the last two years, and I was behind the wheel on all the car's best runs, so I don't think I am the problem.
I am just going to yank the chip and MAF, and then run it to see how it does w/ just the exhaust and K&N. Then I'll put the chip and MAF back in and see what it runs. Then I'll be be able to see if anything is going on. I'll let you guys know what I find.

10-21-2002, 05:33 PM	#1
91LX2Bfast Registered Member Join Date: Dec 1999 Location: Warrington, PA Posts: 694	Low mph in 1/4, any help? Car: '99 GT auto Mods: Bassani o/r X, Flows, RFFperformance/DMann chip (from Stangnet if you don't know,) 80mm LMAF, 22C plugs. Stock, the car turned a best 1/4 time in 14.22 @97.5 mph with me manual shfting it the first time out to the track. That was on a 2.08 60ft time. Yesterday my brother gave me his car to take and run at the 15th Annual Fords at E-town and temp was also in the mid 50's with liitle to no wind and very low humidity. All day the car ran 14.1-14.2's between 97.2-97.8 mph with the mods. I am not worried about the ET because I was getting some tire spin off the line and 60ft times were 2.18-2.26 all day. It'll go 13's with traction, and I know the shift points are set perfectly because now manual shifting only slows the car. What I don't understand is why the car didn't pick up any mph with the mods. The X-pipe alone is usually be worth 1mph, and the chip's functon of increased timing and locking up the TC, etc, should be wort another 1mph. I fully expected to be trapping around 99 - 99.5mph. There was another equally equiped auto GT with only exhaust, Diablochip, and aftermarket MAF trapping at 99.5-100mph, right where I think this car should be. And with the car giving a little spin off the line, that should only increase MPH slighty more, so I don't know what gives. Any comments or suggestions? We are going back to the track with the chip removed, stock plugs, and stock MAF to see what the car runs in that form. And then we'll throw the chip, colder plugs, and LMAF in and see what happends. BTW, I ended up going to the finals and taking runner up in the Trophy Stock class I broke out in the final by .033 At least the car is pretty consistant. But I can't be mad because I had a great time. __________________ '97 T-bird LX 4.6L 2V, auto SVO heads/intake, Vortech T-trim, front mounted intercooler, blower cams, Cobra crank, Manley H-beam rods, JE pistons, Aeromotive fuel system w/ 42# injectors, and much more No times yet

10-22-2002, 09:11 PM	#2
SleeperGT Registered Member Join Date: Sep 2002 Location: Ponte Vedra Beach, FL Posts: 122	I Might Be Wrong 91LX - Since nobody else has responded I'll throw my lame 2 cents in. I'm a little confused by your post. Are you comparing your car to your brothers car or comparing the same car? It sounds like the same car. Anyways, if your question boils down to comparing the same car it sounds like the issue is the car ran 97 mph stock and now with all your mods it still runs 97 mph. I could be wrong but most of the stock '99+ GT's I've seen at the track run low to mid 90 mph's. I know folks are going to get on and say they've seen stock '99's run upper 90's and even 100, but everytime I've been to the track that's what I've seen (then again I'm in FL and it has always been in the high 80's temperature wise). So if your car is one of the lucky stock ones which run upper 90's, then your mods (especially the chip upgrade) would be just an even swap possibly. From all I've read the '99+ cars have pretty decent exhaust systems, so unless your blowing or gassing your car the exhaust work won't get you too much (I'm sure it sounds faster though !) I'm not sure what 22C plugs are, but I've never heard of a plug upgrade doing much for performance (actually measured at the track, not the butt dyno), unless the replaced plugs were shot. I would say if you put a SC or nitro on your car the exhaust and LMAF would help, but doing this just on a stock car might not help as much as you would think. Also was the chip programmed to handle the exhaust and LMAF? I made only three mods to my car and gained .4 seconds and 5 mph (LMAS and Anderson PowerPipe, and Diablo Chip), however the chip was specifically tuned for the other two mods (and my car is SC'ed). If the chips doesn't know about the mods you've done, you won't get as much gain. Well there's my 2 center of rambling and I'm sure it didn't help much. Your idea of running at the track back in stock configuration and then swapping the mods back on sounds like a good idea. I'm curious to here of the results, keep us posted and good luck with this. __________________ '00 GT 5-spd Vortech S-Trim 3.1" Pulley Paxton Air-to-Air Aftercooler 90 mm MAS 42 lb injectors Cobra Fuel Pump 70 mm AccuFab Throttlebody C & L Intake Plenum 2 1/2" X-pipes Anderson PowerPipe MagnaFlow Mufflers Diablo Custom Chip 3.73's Steeda Lower Control Arms 358 rwhp (Mustang Dyno) New Track Times Coming Soon

10-23-2002, 04:12 PM	#4
Dark_5.0 Registered Member Join Date: Apr 2001 Location: Staging lane Posts: 4,337	Its weird how two of the exact same cars run different. I am at 3000ft of altitude and my cobra runs 100-102 mph in the 1/4 bone stock. No one else with a stock 99-01 cobra in my area can even hit 99mph much less 100. Maybe its the driver. No offense. Later, __________________ 92' LX-Big brakes, Lots and lots of suspension, GT40X heads, Ported cobra intake, stock cam, Vortech SC trim. 00' Lightning-Stock 88'CRX-13 second ego killer

10-23-2002, 08:52 PM	#5
91LX2Bfast Registered Member Join Date: Dec 1999 Location: Warrington, PA Posts: 694	No offense taken. There's really no driver error to occur except on launch, and spinning would increae mph even more. I have logged a good number of passes down the 1/4 in the last two years, and I was behind the wheel on all the car's best runs, so I don't think I am the problem. I am just going to yank the chip and MAF, and then run it to see how it does w/ just the exhaust and K&N. Then I'll put the chip and MAF back in and see what it runs. Then I'll be be able to see if anything is going on. I'll let you guys know what I find. __________________ '97 T-bird LX 4.6L 2V, auto SVO heads/intake, Vortech T-trim, front mounted intercooler, blower cams, Cobra crank, Manley H-beam rods, JE pistons, Aeromotive fuel system w/ 42# injectors, and much more No times yet

10-22-2002, 10:33 PM	#3
91LX2Bfast Registered Member Join Date: Dec 1999 Location: Warrington, PA Posts: 694	Well, all the 99+ GT's around here trap between 96-100mph stock, so maybe its an elevation thing. I am comparing my borther's car's performance on two equally temp/humdity days. The chip was programmed with the LMAF and exhaust in mind. The 22C plugs are 1 step colder plugs to prevent detonation with the full advanced timing in the chip. Car runs 93 octane. Its proven that an o/r X-pipe is worth up to 20 HP at 6000rpm on a stock GT. Now thats not peak HP, but it's HP none the less. It should be worth almost 1 mph on a stock car. ET has dropped, or at least will drop into the 13's with traction. But I am concerned with the MPH. Like I said, an equally equipped auto GT was running 99.5-100 mph all day with an exhaust, Diablochip, and MAF. So I know it wasn't the weather.