I think what someone was trying to say, was that possibly your engine was actually never turning 3200 rpm. That maybe (I don't really know how the tach gets its info) the tach was off the same way your speedo was off. I have the hypertech also but have only tried the regular settings so far and I'm not impressed. But I'm curious if anyone else has experienced this? Does larger tires and gears throw off the tachometer, or do these mods have no effect?

 

I don't understand how this works. What in the Hypertech would cause the gear ratios to change for a standard transmission? As has been pointed out, this is a mechanical connection--no software involved. The only way I can think of that the Hypertech would effect it would be if during the first test run (with the stock Trailblazer as the measurement standard), you didn't have the torque you wanted in sixth gear, so you were cruising along in fifth. And in the second test run (where you don't specify a test standard), you had a little more torque, so kicked it into sixth.

Please don't think I'm trying to ridicule you. I'm simply trying to understand what's going on with this device. And I'd prefer to not spend $400 to find out (that's the major advantage of JK-Forum, after all).

 

Think of it this way: Does your tach work when the vehicle is stopped?

 

I meant, I checked what speed I was going with my portable navigation on my trailblazer to make sure the MPH on the navigation was correct and it is. It had nothing to do with the performance of either vehicle, just the mile per hour.

 

Guys, I think all he's trying to say is he recalibrated his speedo. Before, he when his speedo indicated 65 mph he was turning 3200 rpms. Now when he's running gps-verified 65 mph, he's turning 2600.

 

I'm trying to say that-

Before Programmer - 60 MPH on speedometer = 65 MPH on navigation = 3,200 RPM's

After Programmer - 65 MPH on speedometer = 65 MPH on navigation = 2,600 RPM's

That's it, there is no brain surgery needed, no myth buster's needed. It is what it is.

 

I can't help it, I've been following this thread a while now and I have to put my two cents in. Unless you regeared or changed tire size it is physically impossible to run different RPM's. The Hypertech won't do this. Something is wrong with the data.

 

I went and ran the data through an RPM calculator. The 3200 RPM figure at 65 MPH would be correct with 5.13's and 35 inch tires in 5th gear which is a 1:1 ratio. In 6th gear, same gears and tires, 2700 is the theoretical RPM for 65 MPH. Are you sure you didn't get the 3200 RPM figure in 5th gear? That would make all the data correct.

 

Well by your first post you indicated you could sleep now that your jeep was turning 6 hundred rpms less after the programing. That sounds like you thought the program done more than it actually done which is correct the the gear and tire size so the tach and speedo reads right. Which is what it done. No brain surgery needed.

 

I was in 6th gear both times.

I don't want to start a war, I was just sharing some info. I don't know what other way's I can explain it, so I can tell you all I will no longer comment about it. Simply because it is obvious people don't believe me for whatever reason, I have nothing to gain by lying about something as little as this.

Happy Easter.