Better mileage ?

[Jeremiah]

Originally posted by Kilby

Taller tires aren't going to give the rpm reduction that I want but I will be getting taller tires anyhow.



I spoke with GV directly and they assured that you do not need an extra crossmember to support the weight of their unit. Since the rear DS is a two piece design, all they need to worry about is the front have of the DS and it's operating angles. I'm sure they've installed enough of these units to know how to correct the angles. I hope anyhow.



Reguardless, I'll let ya know in a couple of days how it all works.

If you go from 17" wheels and 265 R70 tires to 19. 5" wheels and 265 R70 tires, you will drop the rear end ratio from 3. 73 to 3. 44. In my book that's a huge drop in rpms.



You didn't say you were having GV install the over/under. Maybe they will guarantee it for you. I talked to an installer who was recommended by GV and he said the cross-member was needed.



Me, I don't know but his recommendation and warning about out-of-line vibration was good enough information to scare me away from doing it. Good luck with your truck and let me know how it works out for you.

 

[Kilby]

I'd consider 19. 5" rims if I had a 2wd truck but it's a 4x4. Not too many (if any) choices in a good off road tire in the 19. 5" range.



GV themselves isn't doing the install. They recommended a local shop to me to do the install. They set everything up over the phone & www.stcperformance.com will be doing the work. GV says STC does the third highest amount of installs and is very good. <shrug> I guess we'll see.



Dunno what to say about the crossmember thing. I don't even think the GV has the provisions for a crossmember mount. I'll find out for sure soon though.

 

[Jeremiah]

Originally posted by Kilby

I'd consider 19. 5" rims if I had a 2wd truck but it's a 4x4. Not too many (if any) choices in a good off road tire in the 19. 5" range.



GV themselves isn't doing the install. They recommended a local shop to me to do the install. They set everything up over the phone & www.stcperformance.com will be doing the work. GV says STC does the third highest amount of installs and is very good. <shrug> I guess we'll see.



Dunno what to say about the crossmember thing. I don't even think the GV has the provisions for a crossmember mount. I'll find out for sure soon though.

You are correct, they don't. The crossmember was fabricated by the install shop, which I think I told you was also recommended by GV. The shop said they were quite familiar with what needed to be done, but just didn't think it was a good idea for my truck which, incidentally, is a 4-by too. I will be needing tires by winter and, as I recall, Rickson has several manufacturers that sell 19. 5 commercial tires and rims. But they don't have aluminum right now, only steel. I want aluminum.



See if GV or the install shop can guarantee that the final product will run as smoothly as the OEM drive shaft. If they won't put it in writing that there won't be any vibration, I'd hesitate before proceeding. But I am anxious to hear the result if you do proceed.

 

[Kilby]

Huh. Are you sure we're talking about the same company and product? US Gear makes a similar unit too. http://www.usgear.com/dual_range.htm



All I can tell you is I've never heard of anyone using a crossmember in any application for the Gear Vendors. GV says they don't need cm's either. I'll call them tomorrow to be sure and if they say no, it's a go.



One of the previous issues of TDR has some info on the GV being installed in a rig. Can't recall which issue off hand but I don't recall seeing a crossmember in that install either. <shrug> DS vibration (or lack of) is a no brainer. If it vibrates, it comes back out unless they can correct it. I'm sure they know this too. Heh heh!

 

[Jeremiah]

Originally posted by Kilby

Huh. Are you sure we're talking about the same company and product? US Gear makes a similar unit too. http://www.usgear.com/dual_range.htm



All I can tell you is I've never heard of anyone using a crossmember in any application for the Gear Vendors. GV says they don't need cm's either. I'll call them tomorrow to be sure and if they say no, it's a go.



One of the previous issues of TDR has some info on the GV being installed in a rig. Can't recall which issue off hand but I don't recall seeing a crossmember in that install either. <shrug> DS vibration (or lack of) is a no brainer. If it vibrates, it comes back out unless they can correct it. I'm sure they know this too. Heh heh!

You're making me think now. I'll go back and see if I have the literature. Be back in touch.

 

[Kilby]

Issue 40, page 152 shows the Gear Vendor unit installed on the Cannon Ball Express truck.

 

[Jeremiah]

Originally posted by Kilby

Issue 40, page 152 shows the Gear Vendor unit installed on the Cannon Ball Express truck.

I'm pretty positive it was a GV unit. I couldn't find the material they sent me (threw it out after I decided not to have it installed). I looked at the US Gear web page and I think their unit is shorter than what I remember the GV unit being.



Maybe the installer here didn't know what he was talking about. But I decided to play it safe just in case. I figger tall tires and the 19. 5" wheels will do the same thing without the risk.



Keep me posted on how your truck works out, and particularly what your rpms are at, say, 75 mph. Are you running a 3. 73 or 4. 10 rear?

 

[Kilby]

4. 10's. I wrote down some rpm numbers at different speeds to check the differences. I'll let you know for sure.

 

[radar doctor]

19.5 versa 17 in tires

If i change tires from 17 in to the 19. 5 tires, How much higher will the truck stand?? Tks

 

[Scrappy]

mpg's

I have only run two tanks thru it so far, but I am getting 14. 2- 14. 6. just waiting on the 35's to help offset the 4. 10's

 

[Jeremiah]

Re: 19.5 versa 17 in tires

Originally posted by radar doctor

If i change tires from 17 in to the 19. 5 tires, How much higher will the truck stand?? Tks

It's the diameter of the tire after it's mounted on the wheel that counts. Check out http://www.miata.net/garage/tirecalc.html. Enter the OEM wheel and tire size, then the wheel/tire size of the one you're considering. You'll see the difference.



In my case, using 265 tires both ways, the difference was a truck that stands 2. 5" higher off the ground. It's a consideration. You might also consider the change in rear end ratio. If you're running a 3. 73 and go to a 2. 5" taller tire, your ratio will drop to 2. 44.



That's good if you're running solo most of the time (better fuel mileage). Bad if you pulling a 10,000-lb. trailer across the Rockies (less power).



I apologize if I gave you more information than you asked for.

 

[radar doctor]

Tire address

Mr Jeremiah, where is Divide Co. ? Been all over that State and never seen that town. Ha, Thanks for the tire info. The address above doesn't work for me, comes back Error 404, what ever that means. . Bill Central Kansas

 

[Jeremiah]

Originally posted by Dean Upson

I have made the same observation. I am especially careful to completely top off the tank when towing and the computer is right on the money.



Dean

Hi, Dean, I guess I remain the '03 mileage king! In every day driving I get 20. 5 up and down Ute Pass (same as what the computer says), and that includes some city driving in Colorado Springs. I got a high of 24. 4 on a 634-mile trip to Omaha driving 62. 7 mph and 1800 rpm. That dropped to 19. 4 on the return trip when I kicked it up to 75 mph and 2200 rpm.



But as we all know, a clean air filter makes a huge difference. In spite of what the owner's manual says, my filter won't approach 100% clogged. Instead, it reaches 65% and that's as far as it goes. I consider efficiency gone at 65%, at which point I change it.



If I'm not mistaken, can't filter efficiency be observed by watching the boost and egt guages?

 

[Jeremiah]

Re: Tire address

Originally posted by radar doctor

Mr Jeremiah, where is Divide Co. ? Been all over that State and never seen that town. Ha, Thanks for the tire info. The address above doesn't work for me, comes back Error 404, what ever that means. . Bill Central Kansas

H-m-m-m. I just tried it and it worked for me. Here it is again:



http://www.miata.net/garage/tirecalc.html.



Divide is a wide place in the road 25 miles west of Colorado Springs. It's where you turn south off Hway 24 to go to Cripple Creek, the county seat.



Divide is known locally as the "Center of the Known Universe. " Nearby Florissant, 8 miles away, bills itself as "On the Edge of the Known Universe. " Neither village is incorporated, which says something, I guess.



However, that's changing. Both these towns go back to the late 1800s and survived becoming ghost towns only because the railroad and (later on) highway went through them.



Both are going through a Renaissance of sorts because that's where people are moving who don't want to live in Woodland Park, which is a bedroom community for Colorado Springs.

 

[radar doctor]

Info on Co.

Thanks now i know where you are. The address still didn't work, wished some one else would try it and let me know. I get a 404 error. thanks anyway. I HAVE A 03 LOCATED I WANT, A 4X2. NOW I NEED TO SELL A 99 4X4 SLT NEAR MINT. IT IS ADVERTISED IN TDR. . HELP ME OUT GUY'S, SURELY ONE OF YOU WANTS A CHERRY? ONLY 67K MILES. . Oo. Oo. Oo. Oo.

 

[Kilby]

He accidently put a period at the end of the URL. Try this one instead.

http://www.miata.net/garage/tirecalc.html

 

[Jeremiah]

Originally posted by Kilby

He accidently put a period at the end of the URL. Try this one instead.

http://www.miata.net/garage/tirecalc.html

That ought to fix 'im up. That was my fault.

 

[Kilby]

It happens.

Btw, I used to live in Woodland Park a loooong time ago. Haven't heard the words Cripple Creek in a long time.

 

[Jeremiah]

Originally posted by Kilby

It happens.

Btw, I used to live in Woodland Park a loooong time ago. Haven't heard the words Cripple Creek in a long time.

You wouldn't recognize the place now. 7200 people in WP, 22,000 people in the county and casinos along Bennett Avenue. 4-lane highway all the way to Divide. But they've done a good job of keeping the same "look" in CC. They kept the facades and built casinos behind them.



The CC police department has gone from a 3-person department to more than 50 people. Takes a lot of people to investigate bodies in mine shafts, I guess.



My wife is county treasurer. Before that she was clerk and recorder for 12 years.

 

[radar doctor]

Thanks Kilby, It works..... Send me a Buyer and it's worth 300 smakers guy's... Oo. Oo. Oo.