Central WA Baja

[CentralWAbaja]

OK... It was a crash course in gear ratios 101...Spent all morning on the gear calculator...Like I understood all of that Actually I do grasp it fairly well, what I don't know and won't know, is how it all translates to the real world driving. Time will tell.

So I took what Dave Folts Trans recommended and bounced that off of Carl from V-tec performance, he gave me his recommendation....and they were very close to each other. Made one small adjustment to 2nd&3rd gears and here is what we have for ratios/specs

5.14 R&P

1st 3.11
2nd 2.17
3rd 1.56
4th 1.14
#'s now headed to Weddle for the tranny to be built

[ntsqd]

What is the safe redline of this engine?

Cursory fooling around with Excel looks like ~2k rpm's per shift
My very undeveloped thought is that you want to shift at or a little past peak HP and have the gearing such that you're at peak torque. Real world says this is likely impossible, which is probably why we had different trans ratio sets for each race track.

[CentralWAbaja]

Motor makes peak HP between 3500and 5500 RPM's and redline is 6200RPM

Without getting into a bunch of decimal points, here is the aprox breakdown

33 inch tall tire

5.14 R&P -------2500rpm-------3500rpm-------4500rpm-------5500rpm

1st 3.11--------15mph--------- 21mph-------- 27mph---------33mph

2nd 2.17--------22mph---------31mph---------39mph---------48mph

3rd 1.56--------31mph---------43mph-------- 55mph---------67mph

4th 1.14--------42mph---------59mph---------75mph---------92mph

ALL IN*** 6200RPM 104mph

So yea about 1500-2000 per shift and for a few more thousand $$$$ I could close that up with a 5-speed

[Ol'fogasaurus]

I don't think you want to go though the whoops at 104! I do not think you want to jump at that speed either unless you are trying to get back home for a potty break (I'm not talking about camp either). Sounds pretty knarley and fun. Lee

[560]

Close to what I am running in my 5 car but with 002 and 4.86.

Gear ratios are about like a cam, we all sorta kinda know what we want but really do not know were to start, but our buddy's are doing this and that........
That is what I like about STF (and others) that give a great amount of info.

Mike

[Leatherneck]

Seems low on the MPH topping out at 104, 67 in third. What kind of torque is the engine putting out?

[CentralWAbaja]

Seems low on the MPH topping out at 104, 67 in third. What kind of torque is the engine putting out?

With almost 500 hp & 35 inch tires, my diesel pick-up probably would do about 140mph with the stock 3.73 gears, so I changed em out to 4.11's, now it gets to 80mph alot faster and I have only seen 100+mph 1 or 2 times ever

It's a funny thing trying to lay out the gears for what you think you may want it to do. I want it to crawl through the slow stuff without clutching it to much, have a livable rpm drop from gear to gear and still not just use just 3 gears and 4th for overdrive. I guess that is why the popularity of the 5 speed in the desert racing.

As for the torque??? I still have not gotten a dyno sheet. Just going by what the guys I am entrusting my $$$ to help me through all of this.

And honestly...without them even talking to one another..we changed 2nd from a 2.08 to a 2.17 and 3rd from a 1.47 to the 1.56 that is how close they were to being on the same page....even if that was the wrong page I decided not to overthink it to much more. I am second guessing 4th a little as 70mph will still have the motor turning 4175rpm but there is something to be said for being smack in the middle of the power.... always

Close to what I am running in my 5 car but with 002 and 4.86.

Gear ratios are about like a cam, we all sorta kinda know what we want but really do not know were to start, but our buddy's are doing this and that........
That is what I like about STF (and others) that give a great amount of info.

Mike

There is definitely lots of ways to skin the cat as they say. The 5.14 will give me the strongest available R&P And the gears we have selected are "in the meat" of the strong parts there as well....kinda also why we have ended up where we are.

[Leatherneck]

Reason asking about the torque is that you will be able to keep the RPMs down but if the engine has good torque then you won't need the stronger gears, let the engine pull it up. You know about the torque with the truck of yours, same aspect. Not about doing the 100 + but about keeping some of the RPMs down while still being able to put you back in the seat.

[CentralWAbaja]

Yea, kinda why I went with the 3.7 over the 3.2 or 3.5. Better on the bottom end of the power range. But after talking with ALL of the trans guys I did, they all said that the torque is what brakes the trannys. So I kinda have said if I am going to shell out the coin for the tranny, just to have the "piece of mind" I want the strongest combo I could build. I guess trying to have my cake and eat it to....For me the whole care is made up of compromises...It's not going to be the Best anywhere... but I think and hope, it will be Good everywhere.

[560]

I call shotgun on the 2nd ride.. (that will cost me)
Figure the first will be wife or kids.

Mike

[Ol'fogasaurus]

To get serious for a second; you might want to look into selecting a clutch disc and maybe a pressure plate that will handle that torque/HP vs. the traction and drag you should be getting out on the sand If I tore one side of a brand new HD clutch/disc up with a glass buggy, stock sedan transaxle, and a torque-y 1776 on the sand in just a few hours, what is going to happen with your widened and lengthened Baja when you throw that combination of a heavy HP/Torque engine with paddles and sand drag while running hard out on the sand?

Lee

[Busk]

just for what its worth, my hv1 is set like this, 2.4 ecotec with 6800 max
33" tire

5.43 R&P

1st 3.11
2nd 1.93
3rd 1.50
4th 1.22

these ratios were spot on for me out of the box for in the dirt. ( they had already done one for an ecotec car, so they set mine up the same) my only compliant is that 4th gear is just a hair too low for cruising on the high way. 65 mph at 4500 gets a little old after a while. however,i rarely drive mine on the highway for any decent amount of time. so just a heads up if you plan on doing any highway driving

[CentralWAbaja]

Thanks Busk.

Its all pretty interesting to me.

with that combo vs mine

All @ 4500 rpm

1st -1mph =27/26mph
2nd +3mph =39/42mph
3rd-------even money =54.5mph
4th -8mph =75/67mph

All in for me on that combo 92mph at 6200rpm

All good info guys and as always, hopefully somebody else will also benefit someday

[ntsqd]

Is this where I mention a new/used Tilton two disc clutch that I got for a project and now can't use? I'll let it go for what I paid McKenzies for it (consignment deal) plus the ride, a steal. PM for details if interested.

[CentralWAbaja]

This where I simply say....

I don't even know what that is....

The plan right now is to run a Kennedy 9-inch clutch in there. But hey, it's not like I have not been swayed in other directions from time to time