No high speed in these cars I guess

Dave B. · 04-02-2006, 09:26 PM

I was on the interstate today and down shifted to 5th gear to run a Turbo VW of some kind, well I pulled away from him of course but soon as I shifted to 6th I got huge knocking and had to back off, i thought I was just tuned too lean yet Sam says thats not the case, that every one of these that blow up are trying to run at top speed for a period of time, high HP high boost for top end top speed runs, he says these cars simply cannot take bogging in top gears no matter how its set up, what say you?

RF Cobra · 04-02-2006, 10:44 PM

Depends on what you consider high speed I guess. An '03 ran 203 mph on the salt that was putting out 614 hp and 612 lb-ft torque at the rear wheels.

I know 6th will reduce your top speed with stock gears, don't know if the 4.10s are enough to make 6th usable for you at high speed.

RedfireSVT · 04-03-2006, 12:10 AM

High speed runs can and do damage these engines. But by high speed I mean up to 160mph or somewhere close to that speed. It usually takes multiple runs to cause damage but every motor is different. Personally I avoid anything over 130mph. And I can't tell you the last time I did even that.

Dave B. · 04-03-2006, 12:28 AM

why do you figure this a problem? does not make sence to me, I understand the bogging under high boost, but so long as the speed is creeped up on slowly using a low boost as possible, I would think it would be OK, but its not,
So why can a Porche do it and these engines not? how can a Mercedes do it and these engines not? I think a Corvette can do it without blowing up,,,,,
whats the deal mang????

ausie · 04-03-2006, 07:16 AM

I did not have any issues burring the needle last year in excess of 160, then of course I was not in 6th gear either. Both the rear gears and forced induction are still stock on my car. I am sure most know that higher gear ratios in the rear will reduce the top end. Typically at the salt flats, they use a lower gear ratio, otherwise the top speed will be much lower than it can be. If you want to go over 175mph swap out the gears for 3.27 or lower since the stock 3.55 or aftermarket 4.10 or 4.30 may be too big. Also since the valve train is different than the 01 (different cams to make use of the forced induction) the maximum RPM would probably cause valve float if pushed to the 7000 rpm mark that the 99/01 were capable of. As for the Porsche, it was designed for maximum speed for use on the Autobann and in some cases they validate the top speed at 220 or above and I think it has a max of 9000RPM (depending on model) as well as some almost being 800lbs less in mass. And I highly doubt that the boost level from the turbo trim is higher than 10 psi. How many times do you find yourself pushing the car beyond 150? As it is with any vehicle, there will be a maximum amount of speed it will take before parts fail (bearings, drive shaft, valve train, etc...).

SuperG · 04-03-2006, 07:17 AM

That does not sound right...no matter how fast you are going, be it 30, 90, or 160+, the engine is still turning at high rpm's in a certain gear be it 1st, 3rd, or 6th. Afterall, the Cobra is not the only car in the world with this engine and we don't hear about high speed problems with them...

RedfireSVT · 04-03-2006, 08:32 AM

Quote:

Originally Posted by Dave B.

why do you figure this a problem? does not make sence to me, I understand the bogging under high boost, but so long as the speed is creeped up on slowly using a low boost as possible, I would think it would be OK, but its not,
So why can a Porche do it and these engines not? how can a Mercedes do it and these engines not? I think a Corvette can do it without blowing up,,,,,
whats the deal mang????

The deal is the piston to wall clearance. It's too tight which builds excessive heat which is what causes these motors to let go. As much as I love these cars I wouldn't compare the Cobra motor to a Porsche or Mercedes. A blast up to 160 puts more strain on the motor and builds more heat than just flogging on it around town, which can also fry these things. They aren't bulletproof and I personally believe they are flawed.

beerkat · 04-03-2006, 08:37 AM

Most of us do not run high rpm (5500+) for very long in the lower gears. Reading what has been posted makes me think that when running high rpm's for a sustain period of time is when the engine starts to fail.

When doing a road course I might run 5,000 rmp, but that is only for less than 30 seconds at a time.

blk04cobra1 · 04-03-2006, 08:59 AM

Quote:

Originally Posted by RedfireSVT

The deal is the piston to wall clearance. It's too tight which builds excessive heat which is what causes these motors to let go. As much as I love these cars I wouldn't compare the Cobra motor to a Porsche or Mercedes. A blast up to 160 puts more strain on the motor and builds more heat than just flogging on it around town, which can also fry these things. They aren't bulletproof and I personally believe they are flawed.

You pretty much hit it dead nuts on...when you do multiple back to back high speed runs, it creates a ton of heat, which has been known to warp the pistons causing failures...It's not that the car wont do it, its just not recommended to do it back to back...I personally dont see the point of taking a race over 140mph, especially on the street...you have to look at your gearing as well...you pretty much run out of gear around 130mph with those 4.10's

QIK1320 · 04-03-2006, 02:08 PM

I work for Porsche, the same deal applies to them when you're performing mods, especially when you're upping the boost...a 996 tt can handle 1 bar for a long period of time on the high end, but Porsche really over does there intercoolers in terms of size. Anything above that and I would not feel comfortable loading it for too long on the high end.

I used to own a 1987 930 before coming over to the mustang and that car ran 11.50's in the 1/4 with roughly 13 psi, but I never had the guts to stay in it for to long on the highway.

Linn@Amazon · 04-03-2006, 03:27 PM

these cars will not hold up to sustained high speed runs...your 410s are hurting your top end...if you take nothing else away from this post....please listen to these guys about this..it is not open to debate...no matter how well tuned it is..do sustained high speed runs like that and you will be putting a new motor in your car

Dave B. · 04-03-2006, 04:43 PM

I guess it would be ok to go high speed so long as its creeped up on??
the stock engine does what? 8psi? I would think so long as the boost durring accelleration is kept low, then speed could be built up? am I right?

Linn@Amazon · 04-03-2006, 05:14 PM

sustained high speed runs=

it doesnt matter how you get up there

03 cobra toy · 04-03-2006, 06:04 PM

I guess my car is a factory freak.... My car was clocked at 169 mph @ The Texas Mile. I have run my car at least fifteen times with some runs back to back. No problems here

It's all in the tune!

Stock engine
355 gear
2.93 upper
466 rwhp/rwtq (sae)

169 mph was in 5th gear 6K rpm

http://www.texasmile.com/October2004OfficialResults.asp

**cobrabitn** · 04-03-2006, 06:34 PM

David, I don't think your car is a factory freak...I think it freaks out when you drive it....

04-02-2006, 09:26 PM	#1
Dave B. Registered User Join Date: Dec 2003 Location: Florida Posts: 479	No high speed in these cars I guess I was on the interstate today and down shifted to 5th gear to run a Turbo VW of some kind, well I pulled away from him of course but soon as I shifted to 6th I got huge knocking and had to back off, i thought I was just tuned too lean yet Sam says thats not the case, that every one of these that blow up are trying to run at top speed for a period of time, high HP high boost for top end top speed runs, he says these cars simply cannot take bogging in top gears no matter how its set up, what say you? __________________ 03 Cobra 10th Anniversary Red Stiegermeier Stage 4 ported Eaton 511.9 RWHP 467.7 RWTQ 2,76 Billetflow SC pulley Billetflow Aux-idler all billetflow idler pulleys Accufab single blade MAC cold air BBK Ceramic LT headers X-pipe Magnaflow exhaust Gordsford heat exchanger PST Carbon fiber drive shaft lowered 1.5 inches 18 X 9's AFS running Toyos 275/35/18's front 18 X 10.5's AFS running Toyos 295/35/18's rear Cobra "R" rear wing Cobra "R" hood 4:10 gears Pedator tuned Pro short shifter Hurst "T" handle Promotion Clutch Quad AEM widband gauge Boost & fuel Press gauges drilled & slotted rotors

04-03-2006, 12:28 AM	#4
Dave B. Registered User Join Date: Dec 2003 Location: Florida Posts: 479	why do you figure this a problem? does not make sence to me, I understand the bogging under high boost, but so long as the speed is creeped up on slowly using a low boost as possible, I would think it would be OK, but its not, So why can a Porche do it and these engines not? how can a Mercedes do it and these engines not? I think a Corvette can do it without blowing up,,,,, whats the deal mang???? __________________ 03 Cobra 10th Anniversary Red Stiegermeier Stage 4 ported Eaton 511.9 RWHP 467.7 RWTQ 2,76 Billetflow SC pulley Billetflow Aux-idler all billetflow idler pulleys Accufab single blade MAC cold air BBK Ceramic LT headers X-pipe Magnaflow exhaust Gordsford heat exchanger PST Carbon fiber drive shaft lowered 1.5 inches 18 X 9's AFS running Toyos 275/35/18's front 18 X 10.5's AFS running Toyos 295/35/18's rear Cobra "R" rear wing Cobra "R" hood 4:10 gears Pedator tuned Pro short shifter Hurst "T" handle Promotion Clutch Quad AEM widband gauge Boost & fuel Press gauges drilled & slotted rotors

04-03-2006, 07:16 AM	#5
ausie Don't let the dog drive Join Date: Apr 2004 Location: Kinston, NC Posts: 1,883	I did not have any issues burring the needle last year in excess of 160, then of course I was not in 6th gear either. Both the rear gears and forced induction are still stock on my car. I am sure most know that higher gear ratios in the rear will reduce the top end. Typically at the salt flats, they use a lower gear ratio, otherwise the top speed will be much lower than it can be. If you want to go over 175mph swap out the gears for 3.27 or lower since the stock 3.55 or aftermarket 4.10 or 4.30 may be too big. Also since the valve train is different than the 01 (different cams to make use of the forced induction) the maximum RPM would probably cause valve float if pushed to the 7000 rpm mark that the 99/01 were capable of. As for the Porsche, it was designed for maximum speed for use on the Autobann and in some cases they validate the top speed at 220 or above and I think it has a max of 9000RPM (depending on model) as well as some almost being 800lbs less in mass. And I highly doubt that the boost level from the turbo trim is higher than 10 psi. How many times do you find yourself pushing the car beyond 150? As it is with any vehicle, there will be a maximum amount of speed it will take before parts fail (bearings, drive shaft, valve train, etc...). __________________ 2004 SVT Cobra, Silver, February 2004 SVT Build # 2485 out of 3768 SLP Loudmouth Cat-back UPR double lock firewall adjuster UPR GMS extreme double hook quadrant Wheels: Ford SVT 10th anniv. wheels (track duty) SVE 10th anniv. style 17x9F, 10x10.5R BBS RK Plasma 18x8.5F, 18x10R (retired) (retired) 2001 black SVT Cobra, October 2001 missed but not forgotten

04-03-2006, 07:17 AM	#6
SuperG Registered User Join Date: Nov 2005 Location: Houston, TX Posts: 1,500	That does not sound right...no matter how fast you are going, be it 30, 90, or 160+, the engine is still turning at high rpm's in a certain gear be it 1st, 3rd, or 6th. Afterall, the Cobra is not the only car in the world with this engine and we don't hear about high speed problems with them... __________________ Gary 1997 with Vortech V-2 SQ-trim 420 Hp/376 Tq at 5psi 2010 Shelby GT500 - Stock http://members.cardomain.com/supergr

04-03-2006, 04:43 PM	#12
Dave B. Registered User Join Date: Dec 2003 Location: Florida Posts: 479	I guess it would be ok to go high speed so long as its creeped up on?? the stock engine does what? 8psi? I would think so long as the boost durring accelleration is kept low, then speed could be built up? am I right? __________________ 03 Cobra 10th Anniversary Red Stiegermeier Stage 4 ported Eaton 511.9 RWHP 467.7 RWTQ 2,76 Billetflow SC pulley Billetflow Aux-idler all billetflow idler pulleys Accufab single blade MAC cold air BBK Ceramic LT headers X-pipe Magnaflow exhaust Gordsford heat exchanger PST Carbon fiber drive shaft lowered 1.5 inches 18 X 9's AFS running Toyos 275/35/18's front 18 X 10.5's AFS running Toyos 295/35/18's rear Cobra "R" rear wing Cobra "R" hood 4:10 gears Pedator tuned Pro short shifter Hurst "T" handle Promotion Clutch Quad AEM widband gauge Boost & fuel Press gauges drilled & slotted rotors

04-02-2006, 10:44 PM	#2
RF Cobra Registered User Join Date: Jun 2004 Location: Clemmons, NC Posts: 1,566	Depends on what you consider high speed I guess. An '03 ran 203 mph on the salt that was putting out 614 hp and 612 lb-ft torque at the rear wheels. I know 6th will reduce your top speed with stock gears, don't know if the 4.10s are enough to make 6th usable for you at high speed.

04-03-2006, 12:10 AM	#3
RedfireSVT Registered User Join Date: Mar 2006 Posts: 37	High speed runs can and do damage these engines. But by high speed I mean up to 160mph or somewhere close to that speed. It usually takes multiple runs to cause damage but every motor is different. Personally I avoid anything over 130mph. And I can't tell you the last time I did even that.

04-03-2006, 08:37 AM	#8
beerkat Registered User Join Date: Mar 2004 Location: Myrtle Beach, SC Posts: 471	Most of us do not run high rpm (5500+) for very long in the lower gears. Reading what has been posted makes me think that when running high rpm's for a sustain period of time is when the engine starts to fail. When doing a road course I might run 5,000 rmp, but that is only for less than 30 seconds at a time.

04-03-2006, 02:08 PM	#10
QIK1320 Registered User Join Date: Jan 2006 Posts: 24	I work for Porsche, the same deal applies to them when you're performing mods, especially when you're upping the boost...a 996 tt can handle 1 bar for a long period of time on the high end, but Porsche really over does there intercoolers in terms of size. Anything above that and I would not feel comfortable loading it for too long on the high end. I used to own a 1987 930 before coming over to the mustang and that car ran 11.50's in the 1/4 with roughly 13 psi, but I never had the guts to stay in it for to long on the highway.

04-03-2006, 03:27 PM	#11
Linn@Amazon Registered User Join Date: Jun 2005 Posts: 198	these cars will not hold up to sustained high speed runs...your 410s are hurting your top end...if you take nothing else away from this post....please listen to these guys about this..it is not open to debate...no matter how well tuned it is..do sustained high speed runs like that and you will be putting a new motor in your car

04-03-2006, 05:14 PM	#13
Linn@Amazon Registered User Join Date: Jun 2005 Posts: 198	sustained high speed runs= it doesnt matter how you get up there

04-03-2006, 06:04 PM	#14
03 cobra toy Track Dog... Join Date: Oct 2002 Location: Kingwood,Tx Posts: 2,015	I guess my car is a factory freak.... My car was clocked at 169 mph @ The Texas Mile. I have run my car at least fifteen times with some runs back to back. No problems here It's all in the tune! Stock engine 355 gear 2.93 upper 466 rwhp/rwtq (sae) 169 mph was in 5th gear 6K rpm http://www.texasmile.com/October2004OfficialResults.asp __________________ Track is Crack !! 03 Cobra Sold.... 13 GT500

04-03-2006, 06:34 PM	#15
cobrabitn Dr Jekyll on the street, Mr Hyde on the track Join Date: Jun 2001 Location: Rock Hill SC Posts: 14,649	David, I don't think your car is a factory freak...I think it freaks out when you drive it.... __________________ Cobrabitn 2016 Ruby Red Metallic with Caribou accent F-350 Crew Cab Stump Puller! 6.7 Diesel Automatic with Chrome Package, Off Road Package, 3.55 Locking axles, and Ultimate Lariat Interior Trim Package! 2017 Shelby GT350 Coupe - track car! Mods: JLT True Cold Air oil catch can 2009 Vista Blue Shelby GT 500 Coupe - Garage Queen Tinted Windows JLT True Cold Air Kit Pro-Dyno Tune 526 rwhp - 511 rwtq 1994 Rio Red Indy Pace Car #22 "Runabout" Snake in the grill MGW shift knob 1996 SVT Cobra Wheels 1969 New Lime Mustang Mach 1 Sportsroof - Second owner - bone stock with shaker. One SVT Cobra, one Shelby GT500, one 69 mach 1, and a Shelby GT350 is better than nothing! Custom Data Plates for your Mustang or Ford! Buy "Cool Merchandise" at Data Plates Plus www.dataplatesplus.com See my MSR Video here!

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