Shift Point For Mivec FTO's

JSP-INC · Post by **JSP-INC** » Mon Sep 20, 2004 4:47 pm

I was thinking this morning..
After reading a few dyno charts of fellow fto owners, i see that the power loss occurs once mivec has hit, from about 6000rpm onwards to redline, it's losing power, so to maintain good power, would it better to shift at 6000rpm OR redline it so when u change gear youre close to hitting mivec or are in that mivec range....
Just thought about it this morning.. it's an interesting philosophy....

ruchi · Post by **ruchi** » Mon Sep 20, 2004 5:22 pm

I assume you mean that the amount of torque goes down, as power actually continues to climb through the RPM range, peaking at around 7,500rpm, then dropping off.

If you're talking about shifting to optimise performance, then you want to shift so you'll spend the most time in the power-band. The power-band on the FTO is basically the MIVEC range, so you'd want to shift close to red-line so when you change gears the revs are still in or very close to the start of the MIVEC point (around 5,500rpm).

JSP-INC · Post by **JSP-INC** » Mon Sep 20, 2004 5:39 pm

oh so maximum torque is about 6000rpm but the power keeps puffin' to almost redline.. ahh k...
yup i just looked at a graph again... tails off towards the end (power).. cool ruchi, fanx for that....

Boris · Post by **Boris** » Mon Sep 20, 2004 6:55 pm

I was wondering, since we are on this topic, what is the best point to shift, for example:

7500rpm - Shift when you reach the peak of the power curve.
8000rpm - After the shift, you are brough back higher into the MIVEC range.
8200rpm - Brings you even higher after the shift.

I know that shifting at 7.5k doesn't do much benefit, but I do notice very small differences between 8k & 8.2k... 8.2k being on avarage better by around 1/5 of a second

mrx · Post by **mrx** » Mon Sep 20, 2004 10:51 pm

I think you just answered your own question.

Shift as late and as fast as you can, basically. The more revs on board after the change is the important thing.

It takes no time at all to rev from 7500 to about 8200, whereas that 700 rpm is very useful if it means you are at (say) 6000 rather than 5300.

RichardH · Post by **RichardH** » Tue Sep 21, 2004 11:47 am

Shift at redline.

It's not just the torque curve... Once you take the transmission gearing into consideration it's all the way to 8k with you!

- Rich

JSP-INC · Post by **JSP-INC** » Tue Sep 21, 2004 12:33 pm

yeh i think thats the gayest thing i've ever posted... lolz
ahaha i feel like an idiot :p

ruchi · Post by **ruchi** » Tue Sep 21, 2004 12:36 pm

Jun, it's a valid question, and I'm sure there's others who've wondered the same thing but haven't asked. So good on you for doing so.

Leigh · Post by **Leigh** » Wed Sep 22, 2004 1:05 am

well an example of where shifting before redline is good, is in my brothers Starion. Redlines at 6.5, but his peak is around 5. so shifting around 5300-5400 or so brings him into the powerband on shift without wasting too much time on the power decline after 5.

as a side note.

here is a dyno I had a few years ago.
this is when I had a different intake set up to what I have now but is still relevant.

http://www.angelfire.com/apes/blackhawk/Ftodyno.jpg

, but it shows it seems to keep climbing to 8300 when it cuts out. where as the spec sheet says it should peak at 7500.

ruchi · Post by **ruchi** » Wed Sep 22, 2004 10:37 am

Leigh wrote:but it shows it seems to keep climbing to 8300 when it cuts out. where as the spec sheet says it should peak at 7500.

Correct me if I'm wrong, but this test was done in 4th gear and you've got a manual, which means the speed-limiter kicked in before the rev-limiter did. From memory it would of kicked in before you hit maximum power too.

The guys in Sydney had a dyno day a little while back, and this graph is virtually the same as those who did it in 4th gear manaual / 3rd gear auto. If you want to get a dyno graph of the entire rev-range you'll need to drop it down a gear, or overcome the speed-limiter.

Leigh · Post by **Leigh** » Sat Sep 25, 2004 5:11 am

yep the blue one was done in 4th, and the green one is in 3rd.
Still wouldnt mind seening a graph goin to 9k!

G_A_V · Post by **G_A_V** » Sat Sep 25, 2004 2:15 pm

when it says corrected horsepower does that mean at the engine ?? or at the wheels. Because 165.8hp is a lot at the wheels, but not much at the engine

G1 · Post by G1 » Sat Sep 25, 2004 2:52 pm

yep that looks exactly like my graph, the speed limiter cut in, and peak was never reached... the green one obviously did. if you look closely there is a flat spot and another rise on the green one. on the blue one, it never got to the final peak.

that flat spot comes on around 7000 rpm, so there is at least another 1000rpm left

G_A_V · Post by **G_A_V** » Sat Sep 25, 2004 2:58 pm

I think gr's reach their peak before the speed limiter in 4th, mine peaks and starts to dip just before the speed limiter