352 transmission horsepower limits

[literarymadness]

Does anyone know the horsepower limits on the 352 transmission.  I am having my TC motor rebuilt and upgraded.  It is just about done and should now be around 125 hp at the wheel.  It was dynoed at 103 wheel hp a year ago with the rev limiter set at 5500 rpm.  I blew a head gasket in February and decided to do major upgrades if the engine was coming out anyway. 

[Clifton]

It's torque that is the limiting factor.

[SwiftDB4]

 My 336 box held up for years with a 160hp 121 lb.ft. 807G Gordini engine. Would think your 352 could easily handle your TC.

[literarymadness]

SwiftDB4: That's good to know.! Was that 160 hp at the crank? 

Clifton: How much would "too much" torque be?

[BDA]

What I understand is that the key feature is the number of spider gears. The workshop manual says, in so many words, is that a 365 is basically a 352 with a fifth gear. The 365 has four  spider gears so that implies to me that the 352 also has four.

Unfortunately, I don't know for a fact how many spider gears the 352 has. Maybe somebody who knows will pipe up with the real number.

[literarymadness]

BDA:  What kind of transmission do you have in yours?

[BDA]

I have an NG3.

[Roger]

The Special in UK trim had about 125bhp with 352 or 365 transmission, as standard.
You should be fine.

[jbcollier]

Ditto, you should be fine.  The 352 has the same diff as the 336.  A simple way to upgrade the 336, 352, 395 diff is to fit a torsen limited slip unit from Quaife.

[literarymadness]

Thanks JB!  I will look into that.

Roger: A UK Europa Twin Cam Special has only about 95-100 hp at the rear wheels.  A new Fed spec TC only had about 80-83 hp at the rear wheels.  That 126 hp was bhp or gross horsepower measured at the crank.  And Chapman was notorious for exaggerating horsepower numbers in the name of selling more cars. And most Lotus press cars seem to suspiciously put up higher numbers than real world vehicles.  My engine should have about 125 hp at the rear wheels and about 150-160 hp at the crank when it is finished and I am having it tuned more for torque at lower rpms.  For the record when I first got the TCS it dynoed at a whopping 79 hp at the rear wheels.  Before I blew the head gasket 6 weeks ago, I had it up to 103 rwhp, after adding headers, electronic ignition, and street cams.

[SilverBeast]

Wasn't Certifieds engine dynoed at 150bhp at the crank when he had the engine rebuilt? I think he posted  a plot in his epic rebuild thread.

[literarymadness]

Certified's engine was 148 hp at the crank.  He had a Weber head which has the power higher up in the rpms and a little less torque. I kept the Strombergs because they have more even powerband and more torque at low rpms. Also he didn't drive it long enough to see if the transmission was up to it long term.  Those horsepower numbers are getting towards Type 47 horsepower numbers (160+) and they had heavy-duty hewland transmissions. People drive Elans all day long with those numbers but they don't have a Renault transmission. But I am going to look into JB's suggestion.

[Certified Lotus]

Certified's engine was 148 hp at the crank.  He had a Weber head which has the power higher up in the rpms and a little less torque. I kept the Strombergs because they have more even powerband and more torque at low rpms. Also he didn't drive it long enough to see if the transmission was up to it long term.  Those horsepower numbers are getting towards Type 47 horsepower numbers (160+) and they had heavy-duty hewland transmissions. People drive Elans all day long with those numbers but they don't have a Renault transmission. But I am going to look into JB's suggestion.

I drove my Europa 2,200 miles before I sold it. During that time no issues.

[literarymadness]

Certified:  That is good to know.  I was thinking more like whether the transmission would be good for 10,000 miles + over two years as a litmus test for durability.  I am already $3,000 into engine parts alone plus $1,900 in machine shop fees into the build and I haven't even gotten the final bill for labor.  I am hoping the total for everything is around $8,000.  Nearly all of the other mechanicals and suspension components have been changed or upgraded over the last two years.  It would be nice to be able to drive a thousand mile trip without worries.  But little unexpected problems can cause major issues.  My car was running perfect up until six weeks ago when on a trip back from the Florida Keys, the water pump flange fell off taking the pulley and belt with it.  I am lucky that the only damage was a blown head gasket and a slightly warped head.

[TurboFource]

I read somewhere that a 352 in a turbocharged twin cam running 10lbs of boost has held up to over 20,000 miles of spirited (not stupid) driving.....also saw an old post in a GRM link where some one said they could handle 200hp which is probably what that turbo car was close to making ( and typically more torque than hp!).