FrontEngineDragsters.Org Forum
Technical => Dan Dishon's Transmission Den => Topic started by: Ponti on February 08, 2016, 01:09:23 PM
-
Hi guys, wondering if anyone can help.
Still thinking of different trans ideas, on a clutch car how can can you set up a direct drive but still include a reverse gear. Engines a blown SBC on methanol 9" rear. How would a direct drive stand up to today's prep'd tracks and newer tyre compounds.
-
these guys have been doing it for years
http://www.nwntea.org/index.php?page=home
7.60's at 190-200mph they are slow off the line but really get moving no issues from track prep
-
I have no experience with a direct drive clutch unit. The concept is simple, a slipper clutch through a reverser box to the rear end. We have a few Pro 7.0 and Pro 7.5 guys running this set up. Some are blown methanol, others are injected nitro.
-
Like Dan said, for reverse just bolt a Lenco reverse unit onto the back of the clutch can. If you don't get one with a neutral position you will need to fabricate a "clutch stick" to hold down the pedal to move the car without a driver.
I can tell you from experience that with a pedal clutch and a blown alky small block you will not be happy with a direct drive setup if you intend to race it. You will not make enough power to get it to launch well. With my 417 Donovan I started to notice gains when I put 25% nitro in the tank. Ran the 7.50 class using 45-50%, and 7.0 class at 65%.
As Paul stated, not blazing off the line, but well over 200 on top end. There's no problem with tires or track, sometimes when the clutch and driveshaft go 1 to 1 there's a little shudder.
Steve K.
-
I can tell you from experience that with a pedal clutch and a blown alky small block you will not be happy with a direct drive setup if you intend to race it. You will not make enough power to get it to launch well.
Steve K.
Is that still a problem if I was slipping the clutch, I know Top Fuel slip the clutch for a way down the track over here.
Just trying to get idea's. Would love to go for a DD car, stand out from all the auto's. Class I would be racing in is a Bracket ET class.
-
No big deal are you running Pro tree or full tree? If Pro Tree you will not cut good lights! Other than that it will work to go out and have fun
Watch this video of some direct drive cars
https://m.youtube.com/watch?v=JmUXChaKIEo
-
The killer will be the between round maintence of the clutch. Index racing is all about consistency, but if in the later rounds they start hot-lapping, there is no time for it.
-
No big deal are you running Pro tree or full tree? If Pro Tree you will not cut good lights! Other than that it will work to go out and have fun
Watch this video of some direct drive cars
Awesome video, thanks for sharing Paul! They don't look ultra long cars, how do they manage to not need wheelie bars? (very heavy nose?)
The killer will be the between round maintence of the clutch. Index racing is all about consistency, but if in the later rounds they start hot-lapping, there is no time for it.
No slipper clutch experience here, but it makes sense to me.
Ponti, hats off to you for trying something different!
-
That NW group came to Sears Point years ago to race NE1,We were sitting around eating sandwiches and he was flogging the clutch. Its not so bad when the rules require clutch and high gear only for everybody, but the only way to keep out of the clutch can is by stacking a 2 speed behind it.
-
I can tell you from experience that with a pedal clutch and a blown alky small block you will not be happy with a direct drive setup if you intend to race it. You will not make enough power to get it to launch well.
Steve K.
Is that still a problem if I was slipping the clutch, I know Top Fuel slip the clutch for a way down the track over here.
Just trying to get idea's. Would love to go for a DD car, stand out from all the auto's. Class I would be racing in is a Bracket ET class.
Remember that top fuel guys are making 8,000-10,000 HP, you will likely be 850-1,000. Also note how hot those clutches are after a run. Please understand, not trying to discourage you, I fully understand the "do it different" theme and feel the same way. I hope you do this set up.
Go get in your standard shift passenger car and try to take off in high gear. Even if you give it more RPM and slip the clutch it's a dog. Not apples to apples comparison obviously, but you get the point. That's what your going to need to address. What are you thinking for a rear gear?
Direct drive cars run kind of like a super gasser on a throttle stop in that the first 300-400' is comparatively slow, but at half track come on very strong. Guys in the other lane are used to running wheel-to-wheel with the competition and don't know where you are at. Can be a killer setup in ET, if you can figure how to make it consistent. The short turn around time between runs makes that difficult, even with a blower cooling the clutch.
If you can gear it right, and don't try to put too much static on the clutch you can make it work.
Steve K.
-
Thanks Steve,
I am struggling to find a reverser unit, living in the back of beyond (UK) in respect of Drag parts. Not sure on rear gears. What do you mean by static on the clutch? Not heard that term used before.
-
Static is spring pressure . Centrifugal is the addition of weighted arms that apply additional pressure with RPM.
-
Thanks Steve,
I am struggling to find a reverser unit, living in the back of beyond (UK) in respect of Drag parts. Not sure on rear gears. What do you mean by static on the clutch? Not heard that term used before.
for a Lenco Reverser sometimes I see them on Inside Top Alcohol on their classified section, maybe the classic funny car page also. As far as rear gears go how much HP are you building, tire diameter, what is your top MPH, and RPM goals? If your thinking 7.60 range I would guess maybe 4.30's or........
-
http://www.frontenginedragsters.org/forum/index.php/topic,1550.0.html
Two speed with reverser
-
Remember Ponti is overseas and shipping - taxes - duty add a great deal to the price
-
Thanks guys, will keep my eyes open. Looking at the picture of the Lenco reverser, how do you fit it direct to a bellhousing.
-
To mount that reverser you need to make an adapter plate. There are also reverse units that bolt directly to the bell housing.
Does the facility where you will race mandate a reverser? If not, you could run without one. Just burn our behind the line, or have a couple buddies push you back.
Steve K.
-
Problem I have is I don't have a large crew, will normally only be just 2 of us so the reverser will just make life easier if I roll over the line.