dwapenyi

iTrader: (3)

The gains are there, it's just more subtle in the 1/4 mile. On the highway, you will REALLY appreciate the MEVI.

If you compare a 5 speed Maxima to an Acura CL-S, the Maxima will keep up with the CL-S to 80 mph, but then the CL-S will take over. WIth a MEVI 5 speeds, even past 80, the race will still be on.

So, in other words, the MEVI is like VTEC for Hondas

DW

Dave B

I did some more calculations last night. Even if you use the G-Force ECU which doesn't raise the rev-limiter, the gain in torque from 3500-5000rpms will help compensate for the big lag in torque between each shift. With the G-Force ECU, the torque drop between each shift is more in line with the USIM.

I've also been studying dynos concerning the switchover points and it looks like 5200-5300rpm is pretty much ideal. The VIM manifold flows like USIM to 5400-5500rpms and then just keeps going. Having the switchover set at anything below 5200-5300 will cause a drop in power until 5500rpms. I wish I would paid more attention and caught this earlier. Things I noticed about the higher swtichover is you can't hear the switchover as well and you rarely get to use the VIM unless you are going all out. By butt dyno feel, it feels a bit better.


Dave

BSwithTF

iTrader: (8)

I may try this and see if it makes a difference. I've tried 4600, 5000, 5200, etc. with all about the same times. Haven't gone above 5200 though. On my dyno with the VI off, I don't peak until about 5400 if I remember right.

Bags

iTrader: (3)

Sorry to jump in here... But if you have a VI and it is working 100%, your car is faster. No if's and's or but's.

And just remeber 1/4 mile times/speeds aren't everything. ANd just like many others said track and weather conditons vary so that does play a small role

dwapenyi

iTrader: (3)

You know, xHypex mentioned something interesting about the 3rd gen VE. It has a check valve on its variable intake so that the runners open slowly, rather than abruptly, like all the 4th gen ones are doing. Maybe the abrupt change in intake length is hurting the car's torque. It's not like the motor needs the runners to be one length and then immediately another length. Probably a slow change would be more ideal. Of course, that may hurt 1st gear and probably 2nd because you go through them so fast, but the fact is, the car makes way more torque than you can really use in 1st.

Food for thought

DW

BSwithTF

iTrader: (8)

I know my car is faster. It's hard to convince people of how much a difference it makes when your 1/4 mile times don't improve. The difference in my car between VI off and VI on are like night and day. Even though I haven't gotten a lot faster in the 1/4 mile, I don't regret buying at all.

Bags

iTrader: (3)

ok.. but when my VI opens my TQ curve is higher than when it is closed. and the TQ loss is beofre the VI opens.

There is more TQ after the VI opens... there is less TQ because the intake manifold physicaly changed and is not longer a sealed chamber.

Maybe I misunderstood what you were saying

dwapenyi

iTrader: (3)

You're right. I was just thinking that the quick opening would disrupt the motor for a second, but then, the dyno graphs I've seen don't support that notion. On the other hand, I don't see how a car with an abruptly changing runner length would be best. You want long runners at low rpms, and short runners at high rpm. The VI changes the runner length from say, 18" to 13". The runner length just immediately changes. I would think that the VQ need s a varying runner length change, 18" at 4000 rpm, 17" at 4500 rpm, 15" at 5000 rpm and then finally 13" at 5500 rpms and beyond. This is just conjecture. When you look at other cars with sophisticated variable intakes, they are continuously variable, like my example.

DW

Dave B

I don't know. The Spec-V SER I saw on the dyno had a very fast and dramatic switchover. With a CAI, the Spec-V borders on "VTEC" switchover loudness. Speaking of VTEC, while they don't have variable intakes, they have a variable cam. Techically its the same thing in that more air is brought in at a specified RPM. The VTEC switchover is hard and fast, so I guess Honda didn't see much reason to introduce a progressive switchover.


Dave

Nealoc187

iTrader: (23)

Does the VE have true dual runners like the SHO or wannabe runners with a secondary plenum like our 4th gen VI.

Bags

iTrader: (3)

OHH. .ok I did not understand.. that makes alot of sense.. thanks for clearing it up.

Hmm, but with the VI closed PEAK power is still 5100 or rpms. and if you open it to early you lose power. So I know what your saying, but I do not think it would work on our current application



BSwithTF- I agree.. I raced a gs400 on the highway and almost won. he was shocked that I kept up

dwapenyi

iTrader: (3)

Now that you mention that, you could be right. I've seen a few videos of 5th gens on dynos and their switchover seems to be a simple dual mode setup as well. Oh well.

DW