Fuel

We are working with the gear company to factor for different ratios, strength, materials.

We are looking at different materials, gear pitch, straight or helical, etc.

Whatever ratio we decide on, it will not be "ideal" for some customers. Due to rising fuel costs, I want a pretty tall gear to reduce rpm to coincide with our low rpm torque producing cam. This might not be perfect for some people that tow heavy. I can produce these out of some exotic material that will hold a lot of power but that might be out of some people's price range. My goal in this project is to make an affordable (compared to over-drive unit) that is as at least as strong as the OE piece, that will put a 3.54 truck with stock tires at 1750rpm @ 70 mph. That will not be tall enough for some people, and will be too much gear for others, but I think it will be the best for the most amount of people. If people are looking for the best MPG a high torque cam, conservative injectors and turbo will need to accompany it to make the whole package work the best.


Zach
 
Very interested in the gear but like you said, Im worried about the towing issues.
 
If you have 4.10's already you should be fine, but if you tow heavy with the 3.54's they will probably be a bit tall for you. I don't have enough money to throw at this project to come out with 5 different ratios so we are working on finiding out what the most popular gearing will be. The other option if you tow heavy, just do 85 MPH.

Thank you for all of the input. We are also looking at doing a hub on the counter shaft that will not have a synchro. It is similar to what the Jericho's have. It will be a little more harsh, but it will be much easier to make the whole thing work, have a longer life and will be slightly more expensive...... Thoughts?


Zach
 
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AH64ID said:
Isn't that were your 175/206 cam comes in?

When I talked to Zach the other day it is an improvement on that cam. Trying to get the best airflow down low and should run out of steam around 3200 RPM. For me it would work out great as it would help spoolup and let me get fueling faster while running clean. This is a daily driver cam for those of us that dont need 4k RPMs or the high lift of the 181 cams.
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i like the idea, my mega only sees highway around 3500-4500 miles a month. If it worked out as described it would pay for itself in no time with the current prices.
 
I'm not ready to do a cam but this one sounds really interesting. I know several guys near me that would jump all over that new 5th gear.
 
The cam sounds great. Id be up for it once the funds are there... I know what Im gonna be savin up for now...
 
burnin oil said:
When I talked to Zach the other day it is an improvement on that cam. Trying to get the best airflow down low and should run out of steam around 3200 RPM. For me it would work out great as it would help spoolup and let me get fueling faster while running clean. This is a daily driver cam for those of us that dont need 4k RPMs or the high lift of the 181 cams.
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Thanks.. I run that grind now and love it! I think it's how the stock grind should have been.
 
Hamilton Cams said:
If you have 4.10's already you should be fine, but if you tow heavy with the 3.54's they will probably be a bit tall for you. I don't have enough money to throw at this project to come out with 5 different ratios so we are working on finiding out what the most popular gearing will be. The other option if you tow heavy, just do 85 MPH.

Thank you for all of the input. We are also looking at doing a hub on the counter shaft that will not have a synchro. It is similar to what the Jericho's have. It will be a little more harsh, but it will be much easier to make the whole thing work, have a longer life and will be slightly more expensive...... Thoughts?


Zach
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What kind of ratio you thinking? Will it not handle the power of towing, or will it just be really tall?

Chris
 
Considering the stock ratio .75 I would imagine that it would be to tall to pull in. More than likely if you could use it to pull it would be lugging the motor pretty hard. I say this because I have dual OD gears in my 5500. Stock OD .74 in the G56 with an additional 17% in the second trans. With 4.44 gears I am spinning 2000 RPMs at 70mph. 3.55s would make this 1600 RPM with the above mentioned .614 OD ratio and a 265/75R16 tire. You would be OK till you hit a hill. Also that jump from 4th to 5th would be a 38% drop in RPM from the extra 17% gearing. Great for cruising but would kill you loaded down.
 
I also agree, looks like any type of heavy towing is out. The 3-4 is a big enough gap already let along the new 4-5. Im really interested though, fuel mileage is king.
 
I'm at 1700 at 70mph with my 3.54s and 35s in my auto. Its boggy. Even when I had the 62 or 66 it was boggy. Wouldn't be fun to tow with at all.
 
Roachie, you would be just under 1900 RPMs with your 4.10s using the above mentioned setup. Other than the hard drop between 4th and 5th you would be alright pulling a medium sized load. I wouldnt want to try and pull 15k lbs through east TN at the speed limit but other than that it would work. Pulling my 5vr through WVA on I64 I could run 5 over which is 17% OD pretty easily but getting above that was not going to happen. Even running on a 175HP tune (now on 120HP). That was 15k lb windsail so a lower load may be feasable. I think that you would be fine, it is just the 3.55 guys who want to tow that I think would be disappointed.
 
I want the cam and gear for my 99. I don't plan to tow more that 5k with it, ith that much. Curently I run 2500 @70mph with 275's. This truck is my dd and 95% of my commute is interstate, I see the 4th/5th split being a small issue.

I wanna see how much of a drop this will be though. Right now my only options is to throw some 35's on the back.
 
burnin oil said:
Considering the stock ratio .75 I would imagine that it would be to tall to pull in. More than likely if you could use it to pull it would be lugging the motor pretty hard. I say this because I have dual OD gears in my 5500. Stock OD .74 in the G56 with an additional 17% in the second trans. With 4.44 gears I am spinning 2000 RPMs at 70mph. 3.55s would make this 1600 RPM with the above mentioned .614 OD ratio and a 265/75R16 tire. You would be OK till you hit a hill. Also that jump from 4th to 5th would be a 38% drop in RPM from the extra 17% gearing. Great for cruising but would kill you loaded down.
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I run 70mph at 2K RPM in my old 12v....at 1600RPM I could still tow what I need. Maybe it would lug at 40K lbs, but I tow anything up to that and never have ANY power problem running 70 @ 2K....power isn't the issue. EGT's might be, but I can tow at 35K gross and only have 800* EGT's now...


BgBlDodge said:
I'm at 1700 at 70mph with my 3.54s and 35s in my auto. Its boggy. Even when I had the 62 or 66 it was boggy. Wouldn't be fun to tow with at all.
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You couldn't do it with a 62 or 66's that's for sure....My 58ET or a 60mm charger could do it I think.

burnin oil said:
Roachie, you would be just under 1900 RPMs with your 4.10s using the above mentioned setup. Other than the hard drop between 4th and 5th you would be alright pulling a medium sized load. I wouldnt want to try and pull 15k lbs through east TN at the speed limit but other than that it would work. Pulling my 5vr through WVA on I64 I could run 5 over which is 17% OD pretty easily but getting above that was not going to happen. Even running on a 175HP tune (now on 120HP). That was 15k lb windsail so a lower load may be feasable. I think that you would be fine, it is just the 3.55 guys who want to tow that I think would be disappointed.
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Everyone try's to tell me my 3.55's and my 12v, and my 3.42's in my 6.7 should suck for towing...they don't, and I tow more weight than most.




Hell Zack, send me one, I'll test it at 400-450hp and see how it tows and if it breaks...
Chris
 
Signature600 said:
I run 70mph at 2K RPM in my old 12v....at 1600RPM I could still tow what I need. Maybe it would lug at 40K lbs, but I tow anything up to that and never have ANY power problem running 70 @ 2K....power isn't the issue. EGT's might be, but I can tow at 35K gross and only have 800* EGT's now...




You couldn't do it with a 62 or 66's that's for sure....My 58ET or a 60mm charger could do it I think.



Everyone try's to tell me my 3.55's and my 12v, and my 3.42's in my 6.7 should suck for towing...they don't, and I tow more weight than most.




Hell Zack, send me one, I'll test it at 400-450hp and see how it tows and if it breaks...
Chris
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Agreed. I used to tow pretty heavy with 3.54s and 35s in a 5spd and it did fine.
 
Just got a call from the engineers with their final recomendation factoring for alloys, cost, and durability.


First the stock numbers. THe OE 5th calculates to around a .745 overdrive. So with a 30.5" at 70mph you will be at 2040rpm with 3.55's and 2356 with 4.10's. With our .67 gears, you will be at 1830rpm with 3.55's and 2088 with 4.10's.

I wanted to focus on fuel economy but also focus on driveablility. I think this ratio will be a good mix. For some people 1830 will be lugging at 70mph with a load. For this to work well, you will have to have a conservative turbo, injectors and tuning. There will be a little more of a gap to 5th, but nothing unbearable if you use a few more r's up in 4th.
Conservative setup, a cam designed to maximize airflow at 1800-2200rpm and I think we will have a winner!

What are your thoughts on these ratios? I know they will not make everybody happy, but I think they are a great compromise and will work well for most.

Zach
 
I think for towing that is as far as it can be taken and still might be a small problem. It seems with my knowledge (not much) it would probably be right. Just take 4th till she wont go no more then grab the next one lol. Im interested. Have any idea on price yet?
 
No idea yet. After the test pieces are finished, a lot of the pricing will depend on demand and quantities.

Zach
 
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