I was just out ripping in my car and I realized that I pull faster at 5000 rpms in 5th than i do at 6000 rpms in 4th. It leaves me to believe that 4th gen, rpm to horsepower ratio isn't at 6500rpm. Does anybody know what it is at? Meaning, if I want the fastest quartet mile times, what should I shift at?

 

In a stock 4th gen the max hp is at ~5600rpm.

 

How fast were you going at 5000rpm?! Just the other day, I got up to 4500rpm in 5th @120mph, but I krept up on traffic so I had to slow down.

 

On my dyno max HP was at 5500rpm. At 6000rpm I'm down about 10hp from peak level.

 

That's without VI, right?

 

Without my VIM it is 5600 RPMs

With the VIM is is 6000 RPMs ,6400RPMs then again at 6800RPMS kinda just pleatueas with the VIM

Gotta love that
-John

 

I noticed that on my VIM dyno that it did spike 1.6 HP to have the highest HP at 6100RPMS sorry didn't notice that.

-John

 

John, you think it would be worthwhile to get a JWT just so the redline can go up 500rpm or would that little bit not be worth it? Were the midrange gains that noticeable when you first put it in?

 

Correct, I haven't had opportunity (or money) to dyno it since the MEVI.

 

The midrange is noticable when your in a NA car...but not as noticable as a Y-pipe, or VI...it just feels more peppy. But with the VI I think the ECU is a perfect compliment. Because it allows you to take advantage of HP all the way through the redline...and then when shifting you shift right into almost the peak Torque and right where the HP starts to increase...it is very nice...but It seems that the redline for the ECU on my tach is stopped at 7200...not that I've ever gone up that high

Overall I feel the ECU is definitely worth it, the ECU might also be the cause of a plateau in HP...because I noted the speedtrip and Iansw once they hit the peak HP it didn't seem to plateau as much as mine did. But, it did still stay up there. Got to love that VI.

Hope that helps...if you want on my next dyno day...I can have my friend come and just swap out ECU's and see the difference in the gains but that might be a month or so, but I would be glad to do that to show the HP gain and TQ gain.

-John

 

Check out www.motorvate.ca site. Look under "Engine" & "Engine Dyno (Stock)". Anyway, the curve for his '95 should be representative of your's to show where the peak hp and tq occurs.

 

I see what you're saying, and yes you definitely don't want to stay in 4th gear to 6500 rpm before shifting to 5th...you want to shift much soon like 6000 or less. However, the optimal shift point depends on the gear you're in also. There is so much torque multiplication in 1st that it IS indeed best to wait to redline before shifting. The optimal shift rpm drops for each successive gear. I don't have the exact rpms, but others may post it here or you may be able to run a search and find it.

 

So does this mean that even with the VI power starts to drop after 6100 rpms?

 

I was just saying that I actually hit a peak...from 6000-6800 I hover around 186HP and at 6100 it actually peaked at 188.4 or something here is a speard sheet where you can check it out http://www.vanillaice.com/webmasters...cVI.xls...But, you can clearly see if you take a look at the spreadsheet that there is no comparison between the VIM and non-VIM manifold.

-John

 

Gotcha. Thanks. Can't wait to get enough $$$ to get a VIM myself!!