Driveability

[7tss396]

I recently put a TKO-600 in my 69 Charger which was an auto. Almost every vehicle I own (old and new) is a manual so I have driven all different types and know how they should feel but this is the first TKO-600 I have owned.

The car is really difficult to get going of the line in normal street driving. The clutch pedal is hard and the clutch engages very quickly, but it is not unmanageable. The rear tires are 26.7" tall and the rear end is a 3.55.

I'm thinking that the rear end ratio is the problem but I'm not sure if going from a 3.55 to, say, a 3.91 will make a big difference. I don't want to put up the $ to make the change only to find out it didn't do anything.

Can someone comment on the effect of going from a 3.55 to a 3.91 an its relation to getting the car rolling from a stop?



Thanks again.

[rchaskin]

Get a set of junk wheels, and a set of used tires that are 24.21" tall.

That should be about the same ratio.

3.55/3.91 = .907

26.7 * PI = 83.88 (Circumference)

83.88 * 0.907 = 76.07

76.07 / PI = 24.21" (new tire diameter to simulate gear swap)

[7tss396]

After more reading I'm getting the feeling that the 9.2% change to the 3.91s may not solve my problem. Starting to think it may be the clutch. The car just doesn't have that smooth transition from stopped to rolling that my bone stock 69 RAIII GTO (m20/3.23), 70 SS Chevelle (M20/3.31) and 95 4runner(5-speed/?) have. The charger has a 2012 5.7 hemi (~450hp) in it so the engine is smooth at all RPMs.

Still looking for input though.

[nokones]

What clutch are you using?

[7tss396]

Great question! I bought the kit used (actually was new/never installed but not from a dealer) from a person who bought it for their Charger and never put it in. All I can tell you is that it is rated to 750hp and it's green (Ha!).

I have a hydraulic clutch setup and my pedal ratio is right on but the pedal is still harder than expected. Maybe the clutch is causing my pedal to feel hard and my 'off the line' issues.

Problem is changing the clutch and changing the rear end gear are going to cost about the same. Would sure be nice to know which is the problem but this stuff, unfortunately, is not that cut and dry.

[nokones]

Great question! I bought the kit used (actually was new/never installed but not from a dealer) from a person who bought it for their Charger and never put it in. All I can tell you is that it is rated to 750hp and it's green (Ha!).

I have a hydraulic clutch setup and my pedal ratio is right on but the pedal is still harder than expected. Maybe the clutch is causing my pedal to feel hard and my 'off the line' issues.

Problem is changing the clutch and changing the rear end gear are going to cost about the same. Would sure be nice to know which is the problem but this stuff, unfortunately, is not that cut and dry.

Sounds like a multi-disk clutch. These clutches are either engaged or not engaged, they don't slip at all. You'll get use to it. Modulate the clutch not the throttle when you start out. If you are just grocery getting with your car, leave the rear diff at 3.55 and you'll be fine.

I have a TKO600 with a triple disk clutch and no flywheel. It doesn't take long to figure it out.

[7tss396]

Multi-disk implies multiple disks. This thing only has one pressure plate and one clutch disk...two pieces total not including the flywheel.

[7tss396]

Little more information that may be helpful:

-Wilwood Clutch Master with 3/4 bore
-McLoek Hydraulic 1400 series TOB

[TheJDMan]

A new clutch will generally get smoother to engage as it wears in. I would recommend just driving it for a few a months before you do anything.

[chpr1972]

Did you set the hydraulic throw out bearing clearance like the instructions say? If you measured wrong the release point will be wrong. Then I would look at the clutch ratio to swing petal. That is move the clutch to rod mount a little farther down towards the foot and reset the acuator rod angle so it does not bind in the clutch cylinder and bottom out also. I am in the process of putting a TKO600 in my car and converting to hydraulics. As far as changing the rear gear ratio goes, the TKO500 has a 3.27 1st gear ratio, The TKO600 has a 2.87 1st gear ratio. My Muncie has a 2.56 1st gear ratio so as you can see the TKO's have a steeper 1st gear ratio so that should not be a problem.
If you are use to driving newer cars with a manual transmission they use a steeper 1st gear, but the old muscle cars most 1st gear ratios were in the 2.56 wide ratio and 2.20 close ratio area for Ford Chrylser GM. Also ANY real performance clutch will require more effort than a stock clutch. Any one that drives my car now complains that the clutch is hard to push down but when the 500+ hp and gobs of low in torque [BBC 496ci] kicks in the clutch does not slip!! It also has a slight chatter if you are not careful cause it is hard to slip a high performance clutch.

[7tss396]

Thanks for all of the replies....

I know I got the release point right because I had it wrong and had to take the whole damn trans out to fix it (taking my time to get it right the second time). I'm going to play with the mount point next. Since its a mopar its got that weird mounting point way up high almost in front of the pivot. This is where I was told to mount it so I did. The pedal moves 5.5" and the rod moves about an inch at the moment.

Good point about the Muncie's. Both my Chevelle and GTO have M20's and 3.23/3.31 respectively and I have no problem with them so the 2.87/3.55 combo should be working. Hell, once I get it going I have no acceleration problems.

The clutch is smooth...just tight. I feel like a 16 year old kid driving it cause I've killed it a fair amount of times and the chatter can be unbearable if not let out perfectly.

I'll report back with findings.