Just how lucky can I be??

[BattlestarGalactic]

Well, I went to Thompson Saturday for my next UMTR points race.  Got unloaded, warmed the car up and then made my way to the lanes for first time trial.   Life is good.   Or is it.   5K rpm and BANG!!!!!!   NO go.  First gear has left the building.  Typical.  So typical that it happened near exactly ONE year ago to the day.  I was at Norwalk in 2016 for FF Reloaded #1 and on Saturday night, few rounds in I lost first gear at the line.  I replaced it with a new set from Gforce.  Seems they are only good for one year at a time.

The whole issue is first gear cluster has only 17 teeth.  Yes, it is a very, very tiny, thin walled gear.  With 600ft/lb and 5000 rpm takes its toll on it.  I've got it apart and parts on the way.  Will be good for next weekend for the first race at the NEW Dragway 42!  I can't wait to see what it is like now.

[e philpott]

Is there any room to drop Base Pressure and maybe add Counter ??.. Or are you just at the limit of the First thin Gear ??

[Stangman]

Sorry to hear Larry could have been worse your OK and the car is OK. Keep us informed next week.

[BattlestarGalactic]

Eric, I've been dropping CW for a few years now.  It's on the edge for high gear with the current set up so I can't loose too much total force as it starts to get mushy in the top two gears.  That is when I know I need to give it a 1/4 turn(as it wears, it looses bases pressure).

Doug, ya, nothing tragic.   Just sucks to loose out on gaining points(that I desperately need).   Gforce has parts on the way, car is apart, I pulled clutch to inspect, and everything is ready for reassembly.

A buddy had a much worse day then me.  His brand NEW Gforce GF5R got chunked.  Took out a 4th gear faceplated.  It got jammed into 2nd and 3rd gears.  He went to check clutch and apparently it broke the aluminum pressure ring at one of the stands!   I told him the only reason the transmission broke was clutch was too tight.  This kinda proves it, though it is not what he wanted to hear.  He was whining Sunday about only lasting 27 passes.  Then he admitted the clutch was hitting a bit firm.  Well, duh.

[cjshaker]

Bummer to hear about that, Larry. That sort of settles any thoughts I had about using a G-Force. I know your car is a bit on the heavy side, but 1 year out of a gear doesn't seem acceptable. I don't think I've heard of that issue with the Jerico's. BUT, if I remember right, isn't your G-Force an older unit? If so, did they beef up the newer design?

And while we're on the subject, I have a couple of questions. How can you tell when the top gears get "mushy" from the clutch? I'd assume you can feel less of a 'hit' when you shift, or maybe the RPM's drop a bit slower as the clutch fully engages slower (basically the same description, I guess)? I also assume that the reason for dropping CW is to help on high RPM shifts (quicker clutch release)?

Just trying to get my head wrapped around the ins-n-outs of adjusting a slipper clutch, before I go that route. I know it's better to start on the soft side and work your way up to ideal pressure. Better to sacrifice a clutch disc during the learning phase than tear up transmission and differential parts.

[BattlestarGalactic]

Well, the "original" gear(used from who knows what) that as in the transmission when I got it 4 yrs ago, finally broke last July.  This "new" gear from Gfroce lasted one year(near to the day).  Now, this is the smallest gear in the box so I don't hold anything against it and I really put a workout on it the week before.   Yes, a bit less clutch would likely make it last longer.

Don't worry, you can break a Jerico just as easy(and have more issues getting parts then Gforce).  You can't say one is better then the other.  It still boils down to the car and how it is set up.  I got my gear today(one day service from Eastern PA).

As for clutch tune up and "feel".  It takes time to know the "feel".  Some guys never do and they will destroy parts trying to learn it.  A Data logger would really help, but I've gotten this far without it.  Even that can give a real newbie so much information that his head will swim with what to do next with all that information.  Any competent driver can tell when things aren't just right.  LIFT and deal with it.  Better to abort then make a full pass thinking "it will be fine" and realize you have to tear into it and fix screwed up parts.

You can't start with too little as that will cause you more grief.  You set it up "Decent" and make a hit.  What does it do?  Then address it and work through the whole track.  You have to deal with tires, suspension, launch rpm, and shift rpm so you just work your way through the list the best you can.

I've been playing with counter weight(removed 2+ grams/lever in the last few years) and adding a touch of base to compensate for shift RPM and high gear pull.  A touch less RPM at leave would help, but.......I like to leave hard.   

[cjshaker]

So what is the reasoning for you removing CW? I would think adding base to compensate would, to a larger degree, affect your launch in a negative way, not to mention parts durability?

I was going to mention data logging, but got sidetracked. The only info I see being of real use (AF ratio, fuel and oil psi etc aside) is engine RPM vs driveshaft RPM. Basically telling you how much your clutch is slipping.

[babybolt]

Is your 4 speed a Jerico, G-Force or Ford Toploader?

[fekbmax]

Jerico or G force, either way there both good stuff and have both made updates and improvements over the years.
Larry runs his car hard and often. He probably has as many laps a year as any one here and with his set up i would say that's an acceptable amount of wear.
If I'm not mistaken, his combo is a clutch shifted setup so typically if your using the clutch to shift with you need more base and less counter. As someone mentioned it helps a bit with dis engagement when shifting with the clutch down track. With a clutchless you want less base and more counter to keep the clutch locked up down track while shifting at speed. I have seen him run the past two years at the FE reunion and what ever hes doing works for him, obviously...

[BattlestarGalactic]

Well, clutch tuning is an art.  I'm not good at art.....
I've gone both ways with CW.  Originally I was adding it and removing base.   But after putting bigger tires I needed less clutch at launch and with all the CW it was coming on too strong at launch rpm.  I leave/shift at too close of an RPM change.  So, I need to keep the TOTAL weight at 6500 to keep it locked up in high gear, so I removed CW and added base.  The CW comes on with a curve(rpm) to add to the base weight.  I wanted a lighter curve, so I removed CW.  I hope that makes sense. 

I don't have any real data other then ET and 60ft.  On a good track I've been 1.41 which is really good.  Typically 1.49 to 1.51 is normal.

BTW, I run a Gforce 5spd.  I started with a toploader years ago, got my first Doug Nash in 1997 and have been running this GForce for about 4 yrs now. I shift with the clutch.

I surely don't have all the answers, but I try to reason things out and they typically work okay.  At least on my car.  I try to give others opinions on what way to go.  There are a million ways to set up a clutch car, each one is different due to chassis, power, clutch, trans, gearing, etc.

Oh, btw, I got my gears installed, trans is glued together.  Will be adding fluids and getting it installed Friday night.  "IF" the rain holds on Sat then we should be able to race.

[machoneman]

My questions are: how long does the clutch disc last? Pucks or full facings? Once a new disc is installed, can you run the same settings or is it a start-over deal until the clutch burnishes in?

[BattlestarGalactic]

I get 2-3 yrs out of a "rebuild".   Better at 2 then 3, but I've stretched it out before but my clutch guy tells me that I should do it more often.   The disc isn't worn out, but is cupped along with the pressure plate surface.  You can recut everything and flatten it out and run it til you can't shim it for the correct height.

The pressure plate is like a set of valve springs.  To get a specific pressure, you need a specific spring height.  The disc thickness affects that height, thus as it wears you have to continue to turn the adjusters up to compensate.  There are shims under the pressure plate mounts to get it back into spec also and this also gets your levers back to location.

I run a 5135 sintered iron disc.  Solid surface, solid hub.  You are suppose to break it in with a bit more pressure then typical but not so much you break parts. Make a few hits and turn it back down.

[e philpott]

My questions are: how long does the clutch disc last? Pucks or full facings? Once a new disc is installed, can you run the same settings or is it a start-over deal until the clutch burnishes in?

I have maybe a 1000 street miles on mine over a 5 year period and quite a few dead stop launchs with drag radails , my Base is cranked up to about 1100 pounds for street and don't have a race set up for the track but I will probably send it out to Hyatt over the winter for a freshen up

[cjshaker]

Larry, thanks for the info. Yes, it makes sense to me. I wasn't considering the fact that your launch RPM, together with the CW, had an impact on how the clutch engaged at the launch, but now it makes sense. You know, one of those "Duh" moments (I have a lot of those..lol ) I've seen and remember your posts and pictures of the spacers to get the correct spring height on the clutch set-up.

I know 1st gear takes a tremendous beating, just wasn't aware that the lifespan of that gear is so low. And it was the Doug Nash tranny that I was thinking about that you had problems with (breakage and lack of parts for the old design, if I remember correctly).

I hate pestering you guys with questions all the time, but thanks for always taking the time to explain it to me. One thing I've learned the last couple of years, no matter how much experience I thought I had with street racing, NONE of it transfers to the track. That's a whole 'nother world!

[BattlestarGalactic]

Eric,  Tim Hyatt passed back in 2016 but his son Chris is taking over the clutch business.  On the street, with radials is a whole different animal then slicks at the track.  Once radials spin, then continue to spin.  Slicks hook up and that is what will wear a clutch.

Doug, glad to talk about it any time.  Some say CW only affects shifts, but depending on your launch RPM it IS added to the base pressure to affect lock up at launch.  CW also makes it possible to remove pressure at launch just by lowering your RPM at launch.  Say, like a greasy track.  Drop 500 rpm and you instantly remove some clutch. 

A Nash still has parts available from Liberty and GForce.  Maybe not all the ratio's, but most.  I would say a certain Jericos would be harder to get parts for then a Nash since only Jerico makes the parts for them and they are known for obsoleting older transmission parts.

[cjshaker]

Some say CW only affects shifts, but depending on your launch RPM it IS added to the base pressure to affect lock up at launch.  CW also makes it possible to remove pressure at launch just by lowering your RPM at launch.  Say, like a greasy track.  Drop 500 rpm and you instantly remove some clutch. 

More good info. I think I'm getting a pretty good idea as to how the system is designed to work, now to take theory and apply it to real world may be a different story..lol

On the street, with radials is a whole different animal then slicks at the track. 

Beyond the whole staging and lights thing, I found that the biggest thing that threw me off was the helmet. I was so used to hearing my car a certain way, and I could barely hear it with the helmet on. When somebody is next to me with open headers, I couldn't hear my car at all. That's why I took the exhaust off this year for the FE R&R, not for a performance gain, but just so I could hear my car again.

[BattlestarGalactic]

Base pressure is set, but CW is exponential and continues to multiply throughout the RPM range.  Thus it does affect launch, depending on your launch RPM.

The higher the CW, the faster it comes on and the MORE it amplifies with RPM increase.  I call it a BELL curve and how much CW you have is how steep the curve is and how fast it adds weight through your RPM range.

If you leave at 2K rpm, then it adds little.  I leave at 5K and it is a much larger addition to my base pressure.  I only shift at 6500, and go through about 6500.  I don't have a wide RPM range for the clutch to do it all correctly.  It's close enough, but I'm still tinkering.  With only after 20 yrs I put a window in my bellhousing so I can get to CW without having to pull everything.

[e philpott]

Base P and CW multiplied by Torque , lol , Had a conversation with Blair P a month or so back about my BBM block and going 427 instead of 482 , my thought was the extra low RPM torque of the 482 is going to reek havoc on my clutch or tires if I do go UMTRA South racing or even street for that matter , less low rpm torque with more upper RPM horse power might be better for my situation , there sure are many things to consider .. A data logger would sure make the tuning curve less steep but there sure is lots of Factors involved on clutch tuning

[cjshaker]

With only after 20 yrs I put a window in my bellhousing so I can get to CW without having to pull everything.

I'm curious, and I've been wondering, after your helmet 'trouble', you mentioned a particular track being really strict about the rules. How do you get by with your bell being modified (as many guys do)? I'd also assume it's out of date, SFI Spec wise? Do they just overlook that because they know that adjustments are a necessity? I know many guys say they just don't check it, except for maybe in NHRA points programs. I think UMTR is the only program that you run in(?), and I'm sure you don't have the nit-picking that NHRA does, but you still got 'tagged' for your helmet.

I have a spare Lakewood bell that is in really good 'as-made' condition, and after hearing about all the problems with the Quicktime bells, I'd sure prefer to stick to my tried 'n true Lakewoods. I bought it off an NHRA racer after they forced him to change it. I have no plans of running any Stock or SS classes, or any NHRA events, period, so hoping it's a non-issue.

[BattlestarGalactic]

Eric,  yes it will take more clutch to hold more torque.  CW and RPM help with holding the torque.  If you plan on trying to run drag radials.............good luck!!  I've never heard one good thing about those with a stick car.  Especially if you build a big motor.

Doug.  The helmet was just an out of date thing.  It had to happen sooner or later and Norwalk just happen to be it.  I got to wondering if maybe Beaver had told me back then it was out of date?  I know National Trails missed it and they looked at it.  They are VERY picky.  But typically they don't ask for any SFI stuff from me.  Now I am not that fast, so I'm sure the fast cars are looked at much closer.  I don't sweat it.   Even at the Hot Rod Reunion back in 2006? they didn't ask for SFI information and that guy was THE head honcho for NHRA tech.  The UMTR doesn't do tech, the tracks we race at, do.  Only thing UMTR wants to know is if you have anything electronic in the car.  We don't have much worry about cheaters, the group we have is really nice and diehard old school racers.

Yes, use the Lakewood bell.

[e philpott]

Drag Radials are for street only but thought of driving up to Kilkare and making some easy passes with them just to get a time (MPH) with this motor, I know they won't hook on street at 5000 rpm drop but figured if I had a good 1/4 mile MPH reading I could get a idea of what a good pass could be for ET with a good set up , after Data Logging all those years with my kids JR Dragsters it's extremely hard for me to want a make a pass without one

[BattlestarGalactic]

Yes, you can peddle the DR til you get up to about 3rd gear and then use it to get a decent MPH and that can guesstimate a ET from there.  I've done that with my black car with the BFG Radial T/A's.  I've gotten 111 mph out of it, but only 14.0 in the 1/4.   With 111 mph, it should be 12.0's with some traction.