Anyone Build 302's for MPG? And General Wagon Economy

[pantera77]

One thing is if you do decide to go with a T5, nearly every person who has put one in a wagon has either grenaded the tranny, or their rear end.

[Dave804]

Good to know. What's the cause/remedy for that?

If it's torque I wonder if the 6 speeds are rated for more. Or trying to get that mass moving?

[sly]

it's typically due to the sharper engagement that a manual has over an automatic. Typically it's due to the crush sleeve on the pinion actually crushing some more and causing more lash in the rear gears that ends up destroying the rear gears. Not sure about the T5 itself, but I would imagine it's the same concept.

[Dave804]

Sounds like a few hundo on a new set of rear gears could be good preventative medicine then. I think I remember seeing 3.55's for a small ford rear end for around $200.

[BerniniCaCO3]

I've got a blown header gasket, I average 80mph (read, between 30 and 100) on my short commute to work, and I'm getting 12mpg
That header gasket is getting remedied, finally, in the next 3 days. I was just in denial about my fuel economy for a while, because I dreaded the work that this particular gasket entails (I put on header wrap, and, every last header bolt has its head rounded off)

[pantera77]

Good to know. What's the cause/remedy for that?

If it's torque I wonder if the 6 speeds are rated for more. Or trying to get that mass moving?

Ya stock t5's don't like having to move 4000lbs of wagon it seems.

[BerniniCaCO3]

I've heard that stock T5's are garbage even in lighter cars: I keep on reading about these "world class" t5's that people build (beefier internals to address its weak points, I can only presume).

[gadget73]

How many people have T5 wagons and how do they drive them? Have they all been V8 WC T5 models? I know GoodSam had a 4 cyl T5 that died but I don't recall what he replaced it with. The T5 blows up if you slam it through the gears. It does the same thing in a Mustang. If you drive it a little more sanely and use a shifter that has stops to prevent the shifter from being over-thrown and snapping the shift forks, they don't break near so often. If you bang them through the gears, they die. The old SROD was not much different in that regard, though it took banging through the gears even less favorably than the T5, and it was a 4 speed.

[sly]

Sounds like a few hundo on a new set of rear gears could be good preventative medicine then. I think I remember seeing 3.55's for a small ford rear end for around $200.

and build it back up with shims instead of a crush sleeve.

[Dave804]

Thanks guys. I'll read up. I'm sure since the Eisenhower admin at least a few manuals have been made to bolt up on a 302. I'd like to stay 5 or 6 speed, and find something to get it rolling.

I wonder about the ZF 5 speeds that came in 80-96 trucks. Bolt up to a windsor block with the correct bell housing. Only issue would be the gearing. Then again, with a ZF bell housing I could look at other trannies. I've owned a few BMW's in the 4-5000# area that had ZF manuals.

Pantera, didn't you mention you're putting the T5 back in your car? Are you planning to build it up, or what?

And +1 on shifting Gadget. I learned to drive stick on a '47 Diamond T 201. Taught me a lot about being alert. I see people my age shifting and it looks like they're trying to start a lawn mower.

[Pesty351]

I've only blown up one of my t-5's but I bought it for under a hundred buck with a bazilion miles on it. My "world class","z", or "tremec" or what ever you might know it by has held up to over a year of 400 hp launches on drag slicks and slamming gears. It doesn't sound like you would be beating on it so I think you could make one last for quite awhile.

[Dave804]

Appreciate the vote of confidence Pesty haha. I did make it to 368k on an automatic car once. 90k with original clutch on my only vehicle now. Tremec 6 speeds are what I've been leaning towards. I've seen ones sold built for some hilarious horsepower for about $2k "new".

[Dave804]

I'm up reading about the T56 Magnum Tremec. Hurst seems to build a lot of them for retail sale. These new sports cars are pigs, the curb weight on an SRT8 challenger is 4200lb. There's a company about 3hrs from me that sells a complete kit for $3400. Everything from the bell housing to the rear end. Or, it looks like I can use a used T-5 bell housing and possibly pressure/clutch gear and yoke. 150lbs with fluid. Would y'all pick the 2.66 1st gear setup or the 2.97?
http://www.tremec.com/performance/t56m.html

[sick88tbird]

Thanks for all the input guys, keep it coming!

Don, was that 28-30 with a sedan or wagon? And with that fuel kill, sounds like it might have been habits haha.

I forgot to specify, that was my old fox T-bird...much better aerodynamics than these cars...if you're going t56, I would suggest a viper spec gear ratio...I believe it has the 2.66 first gear and 6th is .50 instead of .62....you could run a 4.30 gear and still get good mileage at 60+ mph. I also heard the viper-spec gear sets are stronger.

Good luck,

Don

[Dave804]

Thanks again Don. Sleepless nights are good for reading- got a lot processed about the T-56. Trouble is they're building some crazy things, and calling it all TR-6060. You can order a 56M with non synchro and mechanical clutch haha. They're currently producing two versions made specifically for the windsors. Looks like I can pick up and use a T5 bell housing too. Seems like they've reversed those gear ratios from stock Viper/TR6060 combos Don. It's either 2.97-.5 or 2.66-.63.

I'm thinking of the 2.66 gear box with a 3.73 rear. Everything I've been able to find has peak torque for a stock 302 listed 24-2800rpm. I'll probably dyno my car before blowing $ to be sure. But if that's accurate the 2.66 box would give me the ability to cruise at most any speed in the 80% efficiency band.

50mph in 1:1 4th gear- 2238rpm
65mph in .8:1 5th-gear 2328 rpm
85mph .63:1 6th gear 2397 rpm.

I hit each of those speeds in an almost daily basis with my DD. Additionally, the 56mag box is rated at 700# torque, and the stock weight on most of the OE applications is around wagon weight.