4.6 4v Struggling through Dyno Today. Help?
11-14-2009, 01:38 PM
#1
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Join Date: Jun 2009
Location: PA
Posts: 41
4.6 4v Struggling through Dyno Today. Help?
A few days ago i had ordered an SCT Xcal 3 Flash Tuner and had taken it to a local tuning shop. I had bought it to mainly correct my AFR because it had seemed to run rich, and to delete a DTC for a post-cat o2 sensor since there are no cats. I had thought this would possibly be the reason it seemed to struggle through RPM's.
On the Dyno, the car made 268 HP before the tune and 273HP after the tune. It had blown a little white smoke mainly after 3,500RPM or so. He had told me to take the car for a test run and i had noticed the car still hesitated to climb through the RPM's. He had shown me the graph and it seems like there is an inconsistant heartbeat almost all the way through the pull. Then, compared to another 96 cobra he did with roughly same light modification making 280 with a much more consistant pull judging by the line.
The Guy who tuned had asked me what i was looking to make out of the car HP wise. I told him that i was aiming for 400+RWHP, and he quickly responded with a headshake no. He had said about buying an 03 cobra motor because apparently the 2V heads make better low end power and yet also less expensive to hit that goal. But my next gameplan was to get a Kenne bell 2.1 Supercharger for the car which had seemed to of been able to support that kind of HP.but with all this talk and the car not tugging right im scared to actually go ahead and Supercharge it. i don't know which way to turn! I guess what i am asking is, do i work this 4V or would it be more worth buying an 03 cobra motor already supercharged, Or just buy a newer mustang in general. Any advice, tips would be greatly appreciated. If anyone would like to see the graph and would like to see for themselves just drop me your email adress and ill be sure to send it to you. thanks.
On the Dyno, the car made 268 HP before the tune and 273HP after the tune. It had blown a little white smoke mainly after 3,500RPM or so. He had told me to take the car for a test run and i had noticed the car still hesitated to climb through the RPM's. He had shown me the graph and it seems like there is an inconsistant heartbeat almost all the way through the pull. Then, compared to another 96 cobra he did with roughly same light modification making 280 with a much more consistant pull judging by the line.
The Guy who tuned had asked me what i was looking to make out of the car HP wise. I told him that i was aiming for 400+RWHP, and he quickly responded with a headshake no. He had said about buying an 03 cobra motor because apparently the 2V heads make better low end power and yet also less expensive to hit that goal. But my next gameplan was to get a Kenne bell 2.1 Supercharger for the car which had seemed to of been able to support that kind of HP.but with all this talk and the car not tugging right im scared to actually go ahead and Supercharge it. i don't know which way to turn! I guess what i am asking is, do i work this 4V or would it be more worth buying an 03 cobra motor already supercharged, Or just buy a newer mustang in general. Any advice, tips would be greatly appreciated. If anyone would like to see the graph and would like to see for themselves just drop me your email adress and ill be sure to send it to you. thanks.
11-14-2009, 03:47 PM
#2
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Maybe its just me but that tuner sounds like he's full of s**t. Put a vortech or a roots blower and you'll be at or above 400whp. Check out the motor, do a compression test and do the basic maintenance to make sure thats not whats holding it back.
11-14-2009, 04:07 PM
#5
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Join Date: May 2009
Location: DFW, TX
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Ok, your tuner is a moron. All cobras after 95 have the DOHC engine. Supercharger should get you the HP that you are looking for. White smoke a hesitation while climbing the RPM's is a bit disturbing. Are you loosing any coolant? White smoke usually indicates water getting into the cylinder and burning off, making steam.
11-14-2009, 05:09 PM
#6
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Join Date: Jun 2009
Location: PA
Posts: 41
Well i was not quick to rule out it possibly being a coilpack, bad plug etc. but it doesnt really feel like that. I don't know sometimes i smash the gas and it will tug hard and sometimes especially after driving it for a while, it will just get real sloppy, and hesitate. Now im not saying the car will literally fall nose forward, i would rather call it a stutter almost. Sorry its kind of hard to explain. The car does NOT leak any fluid, and has good oil pressure. i just did an oil change and it didn't look "Milky" making me think there isn't coolant getting in there. And when i say it blows white smoke its not like its overwhelming but its a noticable puff as soon as you step on it.
With me not being VERY mechanically inclined, im scared to take the car to a shop and have them do guess and check work untill my bill is over the value of my car. I do agree on getting a compression check but i don't know what it should be. and if the compression is good...where do i go from there? I really do like this car and it sounds/looks great. I just need to make sure i don't bite off a bigger peice of pie than i want trying to work power out of this car. Thanks for the support guys. Please keep the advice/information coming.
With me not being VERY mechanically inclined, im scared to take the car to a shop and have them do guess and check work untill my bill is over the value of my car. I do agree on getting a compression check but i don't know what it should be. and if the compression is good...where do i go from there? I really do like this car and it sounds/looks great. I just need to make sure i don't bite off a bigger peice of pie than i want trying to work power out of this car. Thanks for the support guys. Please keep the advice/information coming.
Last edited by 96svtC0BRA; 11-14-2009 at 05:14 PM.
11-14-2009, 06:28 PM
#7
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Join Date: May 2009
Location: DFW, TX
Posts: 1,925
Well i was not quick to rule out it possibly being a coilpack, bad plug etc. but it doesnt really feel like that. I don't know sometimes i smash the gas and it will tug hard and sometimes especially after driving it for a while, it will just get real sloppy, and hesitate. Now im not saying the car will literally fall nose forward, i would rather call it a stutter almost. Sorry its kind of hard to explain. The car does NOT leak any fluid, and has good oil pressure. i just did an oil change and it didn't look "Milky" making me think there isn't coolant getting in there. And when i say it blows white smoke its not like its overwhelming but its a noticable puff as soon as you step on it.
With me not being VERY mechanically inclined, im scared to take the car to a shop and have them do guess and check work untill my bill is over the value of my car. I do agree on getting a compression check but i don't know what it should be. and if the compression is good...where do i go from there? I really do like this car and it sounds/looks great. I just need to make sure i don't bite off a bigger peice of pie than i want trying to work power out of this car. Thanks for the support guys. Please keep the advice/information coming.
With me not being VERY mechanically inclined, im scared to take the car to a shop and have them do guess and check work untill my bill is over the value of my car. I do agree on getting a compression check but i don't know what it should be. and if the compression is good...where do i go from there? I really do like this car and it sounds/looks great. I just need to make sure i don't bite off a bigger peice of pie than i want trying to work power out of this car. Thanks for the support guys. Please keep the advice/information coming.
11-14-2009, 06:32 PM
#8
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Join Date: Jul 2007
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if your tuner told you to buy a 2v 03 cobra motor, throw his card away and never go back. someone capable of tuning a motor on a dyno should at the least be able to give you some direction in how to fix a drivability issue. i would find a reputable tuner.
11-14-2009, 08:05 PM
#9
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agreed that guy is a ****ing moron.
if you want 400rwhp, you can get there on any platform for about the same amount of money. any decent supercharger will max out either a cobra, mach, or GT shortblock (aside from the 03/04 cobra). the 2v does make better low end torque, but the 4v motors spool higher so while both cars may have 400rwhp, the 4v motor will have a much larger power band but the sacrifice is a little bit of low end grunt (who cares....honestly?). so in a race the 4v will win pound for pound.
take your car to another tuner before it blows up. telling you NOT to buy an 03/04 cobra and to buy a GT is....hellarious.
if you want 400rwhp, you can get there on any platform for about the same amount of money. any decent supercharger will max out either a cobra, mach, or GT shortblock (aside from the 03/04 cobra). the 2v does make better low end torque, but the 4v motors spool higher so while both cars may have 400rwhp, the 4v motor will have a much larger power band but the sacrifice is a little bit of low end grunt (who cares....honestly?). so in a race the 4v will win pound for pound.
take your car to another tuner before it blows up. telling you NOT to buy an 03/04 cobra and to buy a GT is....hellarious.
Last edited by MU71L4710N; 11-14-2009 at 08:07 PM.
11-14-2009, 08:56 PM
#10
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Join Date: Jun 2009
Location: PA
Posts: 41
Here are the 3 videos from the tune and after looking again i see it mainly blows the smoke in between shifts...
I looked at the coil packs and they are the origional Motorcraft packs. The wires are MSD 8.5's, and atleast look good. and the plugs are a ?. I guess it wouldn't hurt to change the plugs and packs and go from there. would an MSD 6 or 7A box help anything? If you can, check out the videos and tell me what you guys think, whether it's a problem or not with the amount that is actually coming out. thanks.
http://s861.photobucket.com/albums/ab172/youreadill/
I looked at the coil packs and they are the origional Motorcraft packs. The wires are MSD 8.5's, and atleast look good. and the plugs are a ?. I guess it wouldn't hurt to change the plugs and packs and go from there. would an MSD 6 or 7A box help anything? If you can, check out the videos and tell me what you guys think, whether it's a problem or not with the amount that is actually coming out. thanks.
http://s861.photobucket.com/albums/ab172/youreadill/