boomer123

I am currently running 480hp at the wheels without any problems, and I drive it like any well aquainted mustang owner drives their car... pretty hard at times.

I dont live near a track so I wont be tearing on the car every weekend, but I do like to have fun and get on it when the opportunity arrives.

I just spun a rod bearing and am gonna do a complete engine build with forged internals and blower cams, stronger clutch, and better radiator. Hopefully gonna push out around 600hp or just under.

How long do you think the stock transmission can hold up to such circumstances? Im really debating putting in a T-56 magnum while the engine is out and not waste the money on a new clutch for the current tranny...but let me know what you guys think.

grabber blue gt

I say just upgrade the clutch and use the stock tranny for now. If you were shooting for 600rwhp and going to drag the car I would say upgrade otherwise I wouldnt see a need. The 2010 roush stages 3's on fnsweet.com push around 550+rwhp and dont have any issues.

My vote is upgrade the clutch and drive it as is.

danzcool

If you are on street tires, I doubt you'll put enough stress on the tranny to do much (at least that's my take on it) as the tires will spin before anything breaks.
But... I will probably be upgrading to TR-6060 soon 'cuz I want the gear between 4th and 5th.
My acceleration is pretty flat after 4th is spun out, about half a mile to get from 140-157.

DHILL ENC

Hey guys I have an 07 gt and I am looking to go FI here in the near future but I was wondering. Do you think it would be a better idea to go ahead and do forged internals before I go FI or wait? I do eventually want to get into the 6-700 hp range but I'm sure I'll be content with the 450s to start out with. Also do you see the need for stroking the motor any?

Thanks,
David

2005Redfire6

The 3650 is rated for 450rwtq I believe.

808muscle

Torque is the killer in trannys. I know with the auto that number is 450 ft lbs. Am not sure about the manual and I agree with danz. With street tires they are the weak link.

Dhill, 450 rwhp is fine with the stock setup, beyond that is pushing the envelope. Lots of guys push it but some have blown. Figure out your budget first, you might be surprised at how fast things get expensive. By adding a blower all of sudden you will need suspension work to control it, new clutch, better tires, gauges etc.....if you want to build up your motor, your talking thousands. I hope your doing the installs otherwise labor is gonna kill you.
Having a budget and plan is important.

forensicsteve

I do eventually want to get into the 6-700 hp range but I'm sure I'll be content with the 450s to start out with

Often seen well-balanced S197s with 450 rwhp run faster than those with 6-700. With high hp builds, the rwhp is only one part of the equation.

Transmissions fair better with the limited traction of a street surface. Big difference on the prepped surface of a dragstrip. You know when the dragstrip is really well-prepped......lots more crap breaks like trannies, rearends etc etc. That's why most folk have lame horsepower goals.

JIM5.0

The TR3650 is rated by at 360 ft-lbf as published publicly by Tremec .
A word of caution here, this rating is at the flywheel, not at the wheels.

http://www.ttcautomotive.com/english...ts/tr-3650.asp

Ignore the 390 ft-lbf rating, I believe that is for truck applications.

Major Caveat: HP is not listed. Reason: You can put theoretically unlimited HP through the tranny so long as you never ever exceed 360 ft-lbf.
How is that possible? Lets say you are putting 700 HP at the wheels.
It is possible to get such kinds of HP with only 360 ft-lbf torque at the flywheel. But in order to do it you must rev way high.

Just a quick calculation: Lets assume a real world factor, ~15% power loss through the drive train downstream of the flywheel: that 700 rear wheel HP is about 825 BHP at the crank, which is directly transmitted to the flywheel.

To get 825 BHP crank but not ever exceed 360 ft-lbf crank, you will have to rev your engine to over 12,000 RPM, and that is assuming your hold onto 360 ft-lbf all the way to that RPM mark.

Reality check though: going with mods will not keep you below that 360 ft-lbf mark especially when you are shooting for big HP gains ant not desiring to exceed the 7000 RPM mark (or the stock 6350? I cannot remember the stock redline for the 4.6L 3V). To stay below 7K RPM and make 600-700+ HP at the wheels, you MUST substantially increase the torque to do it.

I do not know what the design safety factor of the TR3650 is, it could in reality take 400 ft-lbf torque at the crank as its failure point, and the engineers dialed it back on the spec sheet to 360ft-lbf with the 40 ft-lbf safety cushion.
But I know for sure the safety cushion will never be more than 300ft-lbf above the gear box's rated torque.

If your street driving is vastly under the 4K RPM mark, you might be fine with such a beast of an engine since especially if the meat of your torque curve does not occur until you are above 4K RPM.
But if your spirited driving often takes you into approaching redline, or your engine begins to through out is massive torque at 3K RPM, yes, you should replace the TR3650 with a stronger unit.
The T56 Magnum you are looking at is rated at 700 ft-lbf torque at the flywheel.

http://www.ddperformance.com/shop/pr...5cPath=107_124

So assuming you are pushing 700 HP at the wheels and assuming a 7000 RPM redline (this is where your peak HP would most likely be) your torque would be 525 ft-lbf at the wheels.
The TR6060 is assumed to have about the 15% drivetrain loss, so, as I calculated above, your power at the flywheel is ~825 BHP.
Your torque you would put on the flywheel would be ~618 ft-lbf crank.

Another caveat to consider: It is possible to exceed that advertised T56 700ft-lbf spec rating with 825 BHP crank.
Lets say you lose massive amounts of torque as you approach the assumed 7K RPM redline. This would mean your peak of 825 BHP crank would be shifted to the left on the dyno graph. and to get that 825 BHP at a lower RPM, you must be pumping out significantly much more torque.

Example: On a dyno given typical humidity, air pressure, etc for your area, Lets assume your 825 BHP does not occur at redline of 7K RPM, for the sake of simplicity, lets say it peaks out at say 5252 RPM.
By calculating 825 BHP at 5252 RPM, you must be also making 825 ft-lbf crank. And there is no real world factor that would reduce this.
Same case here: I do not know what the safety factor of the T56 magnum is, it might take 750 ft-lbf before breaking, but I doubt the safety factor extends to above 100 ft-lbf above that 700 ft-lbf rating.