Chevelle updates - Page 66

**earntaz** · #**651** 09-26-2016, 01:19 PM

Nah -- you've put too much time in this ride ... keep it and get the driveline in it that will survive. There are clutches available to handle your "two-tonner" ... TAZ

VintageMusclecar · #**652** 10-01-2016, 11:07 PM

Lest anyone think I was bullshitting about driving through the clutch or trying to make excuses for the cars performance--or lack thereof so far:

Can you say "carnage"? You can literally catch your fingernail in the grooves and transferred metal on the flywheel.

The disc measures a full .030" thinner now than when I first installed it--most of that is embedded around the inner circumference of the bellhousing as seen above.

This clutch is supposed to be good for 650+ HP and use with slicks.

I'm so disgusted with this right now it's not funny.

I'll decide what to do early next week.

**luzl78** · #**653** 10-01-2016, 11:20 PM

Manufacturer should step up and make good on the clutch

**PxTx** · #**654** 10-01-2016, 11:29 PM

Except it likely is rated for less hp than Eric is currently making. Doesn't appear to be have a manufacturing flaw.

**Ryan1969Chevelle** · #**655** 10-01-2016, 11:30 PM

What happened to the clutch? Overpowered it?

That is brutal:-(

Ryan

**njsteve** · #**656** 10-01-2016, 11:36 PM

You have way too much horsepower. Give some of your extra to the rest of us. [img]<<GRAEMLIN_URL>>/wink.gif[/img]

old5.0 · #**657** 10-02-2016, 12:04 AM

Haven't read through the whole thread so maybe someone has already suggested this, but you may want to look into a custom deal given the horsepressure you're making. I had a custom setup from ProMotion Powertrain in an 84 Mustang about 10 years ago that I couldn't keep an OTS clutch in, worked great.

VintageMusclecar · #**658** 10-02-2016, 02:32 PM

Jeff;

I spoke to Ram last week. When I explained the situation, the guy was like "Yeah, with your power & weight, you're past the limits of that clutch." Would've been nice if the tech that I spoke to the last time I went through this would've told me that instead of recommending this Powergrip HD.

Paul;

This clutch is "rated" at 650 HP--I'm just over 600 at the moment. Obviously you can't just go by HP rating, vehicle weight has to be taken into consideration as well...as my situation clearly demonstrates.

Ryan;

Yup. Big-time.

Steve;

No such thing as too much HP, just not enough aft of said HP at the moment. (FWIW, building HP is the relatively easy/affordable part--it's everything you have to put behind all that HP that bleeds you out of $$$)

Tony;

I'll be making some calls tomorrow. I was hoping to get the car back together to try to get back to the track this Thursday, but that's looking pretty iffy at the moment...and we're rapidly closing in on the end of the season. [img]<<GRAEMLIN_URL>>/frown.gif[/img]

**PxTx** · #**659** 10-02-2016, 03:04 PM

Eric, I applaud your commitment to the manual transmission. I can't imagine my 65 Chevelle any other way.

A good friend of mine, Andy Starr just completed Drag Week with his 56 Chevy, running G Force trans. He uses a Dragon Claw Clutch and an adjustable clutch yammer but frequently kills ring gears in his Dana 60. Stepping up to a set-up like that is expensive and likely will result in a longer trip down a road of breaking more parts and engineering the weak link(s) out of the who car.

Selfishly, I would just like to see a bunch of success, fun & enjoyment for you- in the way of low E.T.s, exceeding your own expextations and minimum carnage on parts. The TH400 offers a quick and direct path to that kind of fun. Might be a harder choice to make than it appears, which I can relate to. Between the time already into the 4 speed and a bit of ego on figuring out how to get the manual to meet your goals- it isn't such an easy choice to make.

This is a bit long, but I thought about your dilemma several times while reading Andy's blog. http://hilborninjection.com/drag-week-2016/

VintageMusclecar · #**660** 10-02-2016, 03:13 PM

Here's some interesting math for those who care to know;

You can calculate your (near) optimal elapsed time by dividing 1320 (length in feet of a 1/4 mile) by the observed trap MPH.

For example--

1320/105 mph should result in an optimal e.t. of 12.57.

1320/110 mph should result in an optimal e.t. of 12.00.

1320/115 mph should result in an optimal e.t. of 11.47.

Note that my last pass ran 115+ mph, but the e.t. was only 12.25, which is .78 off the pace--and that's with severe clutch slip through most of the run. The car has the potential to trap at least 118-120+ MPH without the clutch slipping.

Using the Wallace racing calculator with the following (estimated--do not have actual data on hand for the day) weather parameters:

ET (1/4): 11.47 (which is the theoretical optimal e.t for my trap mph)
MPH (1/4): 115
Weight : (in pounds) 4050 (had the gas tank almost full this time)
Elevation : (in feet) 1000'
Temperature (F): (in Degrees) 75°
Relative Humidity (%): 80%
Actual Barometer (in/Hg): 29.8

We get the following data:

Your HP is 523.06 from your ET
Your HP is 523.78 from your MPH
Your HP Correction Factor is 1.09
Your Grains of water is 108.29
Your DA (Density Altitude) is 1,474 feet
Your DA (Density Altitude) is 449 meters

As you can see that's about 90 HP shy of what the engine actually made on the dyno, but two things have to be taken into consideration:

1) That was not an optimal pass--more on that in a moment.

2) The Wallace calculator shows observed HP while the dyno figures show corrected figures based on SAE weather standards.

SO--let's *assume* (I hate that word) that the car can trap 118 MPH on an optimal pass.

Re-calculating the figures using an 11.18 e.t. @ 118 mph (1320/118 = 11.18), we come up with the following;

Your HP is 554.55 from your ET
Your HP is 565.85 from your MPH
Your HP Correction Factor is 1.09
Your Grains of water is 108.29
Your DA (Density Altitude) is 1,474 feet
Your DA (Density Altitude) is 449 meters

These figures are much closer to the actual observed power figures on the dyno.

Making the HP is relatively easy. Putting it all to optimal use is the *%*@$@^# hard--AND expensive part...esp. when you're trying to do it with a stick in a two ton plus tank. [img]<<GRAEMLIN_URL>>/smirk.gif[/img]

FWIW, if it wasn't for the fact that I would have to buy ANOTHER high-$$ driveshaft to make it work, I'd have a 400 Turbo in the car this week (I have a good core stashed under my workbench).