Sojer

I'm into drag racing more so street racing and all that. I also find good cars for some of my club and I see more and more 3rd gens swaped out the 700R4 for a TH400 TH350 or BowerGlide even some TH200. Why do ppl do that that's like having a 4th gen ss and putting a 1st gen SBC in it stock the 700R4 is better in almost every way they may w8 less idk but let's look at G.R.

700R4. TH400. TH350. 200R4
1st 3.06 to 1.00. 1st 2.48 to 1.00. 1st 2.52 to 1.00. 1st 2.74 to 1.00
2nd 1.63 to 1.00. 2nd 1.48 to 1.00. 2nd 1.52 to 1.00. 2nd 1.57 to 1.00
3rd 1.00 to 1.00. 3rd 1.00 to 1.00. 3rd 1.00 to 1.00. 3rd 1.00 to 1.00
4th 0.70 to 1.00. 4th N/A. 4th N/A. 4th N/A
I don't know what's power glide is the had 2 diff 1s and the both where smaller than 700R4
I herd that the 400 can hold 400hp stock but if u are building a mean street car the 700R4 will d or newer the 700 has taller gears so u don't have to buy expensive tall gears like 4.11 or 3.73 a 3.73 with a TH350 would be the same as a 3.08 in a 700R4. I dnt have a shift kit in my trans and it don't shift in to 4th at WOT and I lost a a few races when I didn't know how to bypass is and I beat even more old schools with 3 speed trans. So why do ppl do it I asked ppl who had them in a Fbody and they said they got it like that. And if u have 1 with a stock 2.73 rear end your car will be slower and u have only 3 gears your top speed will not be high ether, so it would be no point. If u have something like a 300hp motor 700R4 will do 80 bucks on a shift kit u barking threw the gears. Help me understand am I missing something I was into Honda's so there maybe some stuff I missed or its 1 of those things where Honda ppl mod a B18 over H22 I never understood they are almost the same but its bigger 1.8l over a 2.2l the H22 was like th big blocks of Honda's 4cyl. Thanks don't beat me up to much.

zenish

the 700r4s prior to 1987 were weak.a turbo 400 or built 350 are cheeper and stronger.i prefer the 700r4 because of the gas mileage.

justcallmeclassy

iTrader: (1)

Older 700s are weaklings. Newer ones have faster launches and better gas mileage and are built to last.

BTW way I met a guy who put a gen 1 sbc and a power glide in a 97 Trans Am. Not LS1 but still, I wouldn't have lol.

AlkyIROC

You have to see what they look like internally to understand how much power each can handle and why they're so different.

The 700R4 is a great street transmission but for the dragstrip, it's terrible. The gear spread between first and second is too great meaning the rpms drop down out of the powerband after a WOT shift. The OD gear isn't required so that's more rotating parts inside eating up power.

The TH350 isn't bad. The gear ratios are good. You can get them in long and short tailshaft lengths. The downside is they're not all that strong. They can be upgraded but parts are expensive. Exploding a second gear sprag is the most common failure.

The TH400 is the workhorse of GM transmissions. The gear ratios are better suited for brute torque. The transmission also uses a center support to hold up the rotating parts. If stock form, they can only take so much power but even by mix and matching OEM parts, they can be built to handle more power than most people will ever use. There are many aftermarket parts to make them better and it doesn't take as much to make it stronger than what a TH350 needs.

The powerglide was GM's greatest contribution to racing. It was never intended as a performance transmission and they only were put behind 6 cylinder and small SBC engines. The transmission is very lightweight and with only 2 forward gears, it loses very little power as compared to all the other transmissions which was good when you had a lower power engine and wanted an automatic transmission. Since there was a huge market from racers for stronger components, the aftermarket is flooded with parts making upgrade parts for the powerglide the cheapest available. You can now buy a complete powerglide without using a single factory component. You can also spend $5000 on a transmission that can handle 2500+ hp.

I run a basic powerglide in my car. With the amount of torque I produce, I don't need the extra gear to help get me moving. My basic upgrades are a new input shaft with turbo splines. A steel clutch hub center to replace the weak factory cast one. A dual seal servo piston. That's it. Everything else is just better goodies. I use a transbrake and have increased the amount of frictions in the high gear clutch hub but it's not really required.

The 200c transmission has no real performance potential. The 200-4R however shares similar gear ratios to the TH350 but also has an OD gear. For a performance street car, this is a better choice than the 700R4 if you feel you really need an OD gear for the highway. We drove cars for many decades without an OD gear so it isn't really required. The OD gear in all transmissions is weak because you're using a small gear to drive a large gear. The OD just brings your rpms down while driving on the highway to help fuel economy.

The 4L60E is an electronic version of the 700R4. Th 4L80E shares about 80% of the internal components of a TH400 and has an OD but is an electronic transmission and weighs about 250 pounds. My powerglide is less than 100 pounds.

AlkyIROC

The powerglide ratios are

V8 1.76 first gear
6 cyl 1.82 first gear

Both have 1:1 as high gear

There's a small handful of aftermarket first gear ratios available for the 1.76 gear carrier for those who want to change the ratio they start off in. The most popular is 1.80 straight cut gears and I think the deepest is 1.96. A straight cut gear won't force itself against the thrust bearing so there's less friction.