Cool DirtFish story

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Doivi Clarkinen
Dave Hintz has a Holinger main box and a Modena he uses as a spare. I just went through the Holinger a couple days ago as he had broken reverse (just chipped a couple teeth, actually) and we also replaced a couple of gears that the dogs were getting worn on. Only cost about $3200 for the parts...

Good to hear the hollinger units are of decent quality, but holy hell, that's expensive! I've got a 5-speed one in my Evo and at PPIHC in 2009 it started popping out of 3rd gear. Pulled it from duty right after that event, but took a year to actually send it in for a refresh. Motivation to send it in was a failed throw out bearing (clutch pedal sunk to the floor) on the car in 2010 while running a syncro box which cost us a chance at keeping up with the fast guys.

I think I heard it's going to need 2 new gears and some sliders...waiting for a price quote....gulp!

Dave

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DaveK

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Doivi Clarkinen
Dave Hintz has a Holinger main box and a Modena he uses as a spare. I just went through the Holinger a couple days ago as he had broken reverse (just chipped a couple teeth, actually) and we also replaced a couple of gears that the dogs were getting worn on. Only cost about $3200 for the parts...

Good to hear the hollinger units are of decent quality, but holy hell, that's expensive! I've got a 5-speed one in my Evo and at PPIHC in 2009 it started popping out of 3rd gear. Pulled it from duty right after that event, but took a year to actually send it in for a refresh. Motivation to send it in was a failed throw out bearing (clutch pedal sunk to the floor) on the car in 2010 while running a syncro box which cost us a chance at keeping up with the fast guys.

I think I heard it's going to need 2 new gears and some sliders...waiting for a price quote....gulp!

And you thought the Duramax bill was expensive.

On a positive note, you now know that Dave Clark has 10+ years of experience with the company that makes your gearbox.

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Jon Burke
thx again, Pete, I appreciate the novela you've written so far.

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Gravel Spray
a light flywheel and a 7” twin disc will also help the box live longer. I’ve only used the sintered metal discs but Buffum told me they went to the feather weight carbon discs and it nearly eliminated dog issues.

another question for you/kind of playing devils advocate...what you said earlier about the dogs banging back and fourth with a 'clutch shift' makes sense. But if you just depress it halfway (so it doesn't fully disengage, still keeping forward driveline pressure on it, but able to slip for any shock loading), wouldn't this have similar effect as super lightweight twin carbon clutch and lightweight flywheel?

i already have a lightweight flywheel and a fairly light 4-puck disc, I'm just trying to minimize wear with what I got.

Also, to be clear, this is what we were doing at Dirtfish...NOT full clutch-in shifts, but just quick jabs....the clutch point on those trannys is so low, that I wouldn't be surprised if they were even 25% disengaged clutch 'jabs'.

"trust me" , try it both ways your self and see what's smoother, throttle blip or clutching. Even taking a slight clutch dip to release the load hurts the clutch, allows the rpms to come up, then when the clutch snaps shut it's a big wind up and BANG. And if the dog is not on the drive side but "floating" in the pocket (because the relased clutch allows float) it will really wack the drive side of the pocket hard.

When you throttle blip you're releasing the load and also reducing it ever so slightly(so no wind up in the rotating mass), the dog ring is released from one gear and slides right into the next available pocket on the next choosen gear, takes the taper, slides right in. It will litterally, as john says pull right in, and on the drive side of the pocket. You'd be surprised at how smooth it is.

Plus, you dont want to be using the clutch on a mid corner shift as removing your foot from the brakes will unload the diffs man....you'll get some understeer to go straight off!

Those stock diameter puck clutch discs(even the 3 or 4 pucks) typically have more weight at the outter circumference than a stock organic disc, so it's even more energy wound up on the input shaft with a clutch dip. Also due to the reduced surface on the friction area of a 4 puck they have have a lot more PSI working on the very sticky fiction surface for any given PP load, so not real cush enguagement, more like a switch...good load holding yeah but man they are nasty with the engaugement. Think of a 100# asian woman with a 5" stilleto heel to your forhead, would'nt it be a bit more cush if she had flats on?? If you're not going to get a nice twin disc, I'd say run one of those cheap ACT or Exceedy semi organic sprung street discs, it will be less brutal to the entire box and unless you've got 500ft pounds it will be plenty of clutch.



Edited 1 time(s). Last edit at 12/28/2010 12:54PM by Gravel Spray.

hmmmm.....ok, I get it......lots to think about. If I'm going to change anything (clutch/whatever) now's the time to do it. the 4puck I have is sprung, but you're right, its definitely a 'switch'.

and on downshifts/corners, I wouldn't use the clutch anyway...that's what we practiced, practiced, practiced at DF and while it hard for me to get used to NOT going over to the clutch, I did get used to it and its NICE. I was just talking about bliping the clutch on upshifts, but if that's a no-no, I can deal with that. done.

It might take me an event or two to get rid of old muscle-memories and get efficient/quick with the new box. (or maybe it won't, who knows)

thx again (again) for all the advice.

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I always recommend to guys looking to go dog in a 5spd to instead consider a 6spd conversion first, it’s a tad cheaper than a cheap gearkit and the 6spd is bullet proof stock plus you get an active CD.

Won't say "I told you so"..... oh wait....

Great info in this thread, i'm really jealous of you getting to go play in the dirt. Kaps dogbox or no dogbox, beating the crap out of any car is alot of fun, and getting instruction is even better.

Interesting thread. Man... love the sequential box in my bikes. My FJR1300 isn't a small bike, but 150hp is a bunch, and it shifts like butter. Guys ride them hard up to and beyone 100,000 miles. Would be nice to have a tranny like that in a car, but WOW on the $$ to keep these things going. T5 and RWD sounds better every day (for me at least)!