Max sustained speed of stock Terminator?

[96stanggt]

Like mentioned before it's not a guarantee that high speed runs will cause any damage, basically enough people have burned a piston that the power of the internet says "WOT in 5-6th gear=engine death". Basically the PTW clearance is tight to cut down on noise as a loose engine will be loud. The bad part is when metal gets hot it expands, and in our motors there's not a ton of room left for expansion.

Sustained WOT runs will throw tons of hot air into the engine, eventually those pistons will get hot enough and expand enough to meet the cylinder wall. Most people that had that issue though had been doing repeated (like several) WOT runs from a low speed to high speed, that process of going through several gears and into the overdrive gears time and time again is asking for it. Now taking our cars from a highway roll and going to 150-170mph then "cruising" at that speed, I'm sure you could do that for hours. Obviously speed plays a factor as it places more strain on the vehicle to accelerate, but the main issue is being in boost for extended periods of time thats dangerous. I've gone into 5th briefly in a highway race before with no issue and gone from 0-130mph at the dragstrip tons of times with no issues. I wouldn't give a second thought to taking my car out tonight and doing a 40mph to 160mph pull to if I wasn't worried about going to jail, I'd set my Aeroforce to moniter cylinder head temps and have at it.

 

[mu22stang]

...I'd set my Aeroforce to moniter cylinder head temps and have at it.

I didn't realize these readings were correct. What numbers do you typically see under normal and WOT conditions?

[edit] Are you sure we have cylinder head temperature sensors? [/edit]

 

[HEMIHUNTER]

take a look at the motor with the heads off [ penty of pics on the site] and you'll understand the PTW clearence.

 

[Jefe]

:rockon:

[ame="http://www.youtube.com/watch?v=JZXa_hRtT9M"]YouTube- german autobahn blast in 03 cobra 178mph ON BOARD[/ame]
[ame="http://www.youtube.com/watch?v=xAxz_AFelbQ"]YouTube- german autobahn blast in 03 cobra 178mph[/ame]

 

[4.6snakedoc]

thanks that was awesome!!!! How fast was the camera car going when you passed it?

 

[97desertCobra]

So a centri. supercharged Mach 1 with a built motor shouldnt have this problem because of the lack of heat soak from a PD blower, right?

Well like stated its the combined heat from many contributing factors. A centri running a FMIC will have much less heat as compared to a PD blower. Especially with back to back runs. Now since your engine has been built where the cylinder heads updated? Hows the piston to wall clearance? All things to ask your engine builder.

 

[Sonic605hp]

Did that car have a tune?? I thought the stock speed limiter was at 159....

 

[haskett]

Open road racers run 20 minutes or more at high speed / high rpm. I've had overheating problems in the 140 mph class (avg 140, top speed 168) but no problems in the 120 class (avg 120, top speed 140). I plan on some mods for April to re-run 140 without overheating.

More info...
http://www.svtperformance.com/forum...-cant-we-do-5-6-gear-pulls-3.html#post8732540

 

[bcwang]

A lot of the posts here seem to be talking about WOT top speed, or open road racing where it's a lot of slowing down and using power to get back up to speed. Autobahn cruising sounds like it would create much less heat than those other two things especially if you slowly get up to speed. However, I guess the problem is how much drag do these cars produce that you need to use horsepower to overcome?

If I was in Germany with my car I'd test this myself, but here in the states, trying to test how fast you can go without going into boost is probably going to get your car impounded.

I'd be nice to know if the car is capable of sitting right near the rev limiter all day long without generating excessive heat.

 

[haskett]

A lot of the posts here seem to be talking about WOT top speed, or open road racing where it's a lot of slowing down and using power to get back up to speed. Autobahn cruising sounds like it would create much less heat than those other two things especially if you slowly get up to speed. However, I guess the problem is how much drag do these cars produce that you need to use horsepower to overcome?

If I was in Germany with my car I'd test this myself, but here in the states, trying to test how fast you can go without going into boost is probably going to get your car impounded.

I'd be nice to know if the car is capable of sitting right near the rev limiter all day long without generating excessive heat.

FWIW, I've driven a heat-soaked car in a low gear on the freeway at 60mph near the rev limiter testing this. I was not in the boost, but it only took a few (2-4) miles to overheat the car.

 

[thomas91169]

Why the WOT gear pulls Fry the engines?

because idiots t00n their cars to 12:1 air/fuel ratio at WOT, causing insane cylinder temps. These temps, coupled with a piston that isnt designed for such temps and a tight piston-to-wall clearance means that when the piston expands from the heat, it has nowhere to go.

these motors were designed to run 300hrs STRAIGHT in various load conditions in stock form. If you upp the boost with a inefficient blower like the Eaton that starts spewing fire when overspun, and try to run a tune on the edge, you better have a motor build fund started. Gotta pay to play if you wanna tune on the edge.

another solution if you want to run such a tune is to have a motor built for it, with pistons that can take heat and dont expand as much and proper clearances if they do.

Otherwise, guys out there with a 11:0:1 air fuel ratio and relatively sane timing curves are having no issues doing a pull from bottom of 3rd to 5th and up to 160mph.

FWIW, I've driven a heat-soaked car in a low gear on the freeway at 60mph near the rev limiter testing this. I was not in the boost, but it only took a few (2-4) miles to overheat the car.

worst test ever.

you drove at a low speed in 2nd gear doing 60mph at 5,000rpm? you probably also had to use 3/4 throttle at those rpm's. not to mention you dont get much cooling and heat extraction benefit at a lower speed.

its a bit different when we are talking about 120mph in 6th at a relatively low rpm with using relatively low throttle input at speeds that mean lots of air is not only going through the radiator, but is also getting extracted via the heat extractors. The faster you go, the better they work.

 

[laruei]

subn

 

[LuDamiKE81]

I been to 160 running my bud in his gto. We did it a few times that day on the way to the track in mexico. But non where back to back. I know with my 2.76/4lb and no port after about the 4th run it just gets hotter and slower. Ive sustained 130 or so for a few miles crusing while another buddy in his tuned silverado was tapping the limiter trying to get a new motor. But i never really got into boost. Heat is the enemy and with most combos you have to keep and eye out.

 

[Digital]

I would be very curious to see how accurate the "trip meter hack" is vs gps at high speeds.
Not that it's easy to find an area for top speed testing, nor is it hard to find a gps to verify but it would still be nice to see.

From the limited aerodynamics threads it seems that another issue at 150+ is the front end is very unstable over bumps. I.E. the car wants to take flight do to lack of down force.
This car was never meant for true top speed out of the factory but I would image with some lip kits and lowering it would help get to 200 mph.
I don't see why a 500-600rwhp with ~300#s of weight reduction couldn't hit 200mph.

Team Saline - About Page
They have a stock "body" mustang cobra that holds the land speed record for mustangs, they hit 238mph with it.
Granted not on the same engine, they used a 5.0 boss block, and a procharger at 20psi making a little north of 1000rwhp. They also have a lot of weight reduction.

 

[SnakeBit]

The main reason we have tight PTWC is the same reason behind our oil "pressure gauge" being an idiot light. A forged engine can start out with piston slap because a forged piston grows as it heats up, so the designer has to leave room for that growth. So the smaller piston is able to wiggle around a bit and make noise. That was the appeal for the hyperjunkola pistons in pre 2003 engines, those pistons have very small heat expansion. So Ford designed these engines with the bare minimum clearance for better mileage and emissions when cold. If they had reasonable PTWC, then some would complain over how much noise they make when cold. The reason we have a fake oil pressure gauge is because people (mostly female Mustang buyers) complained about how much the oil pressure bounced around, so they gave us the abortion we have today because the needle is steady and complaints are few.

When my motor gets rebuilt, I'll specify reasonable PTWC and live with any extra noise the engine might make when cold.

Finally, as Digital said, the aerodynamics are terrible on these cars. That's why we have a governor which kicks on in the mid 150's. The car just isn't stable at those speeds. It can be fixed, but from the factory, 150+ is a recipe for disaster. Imagine the lawsuits if Ford didn't have these cars speed limited.