Dave B

Today I dynoed my VI. Unfortunately I cannot find the software to my scanner (upgraded computers, sold the old one with the software). What I did was input my HP and TQ into a spreadsheet and plotted my best VI run vs my best pre-VI run. The results are flat out staggering. I gained over 50fwhp and 40fwtq with the VI at 6500rpms.

http://home.earthlink.net/~thunderlt...s/DCP_0014.JPG

The Blue line is pre-VI HP
The Red line is pre-VI TQ
The Green line is VI HP
The Yellow line is VI TQ

As you can see, there is a huge amount of power gained abover 5300rpms. And yes, I did loose ~10fwtq and 10fwhp is various areas below 4900rpms. So, if you want to gain over 50fwhp and 40fwtq, you've got to trade for a slight bit of lowend.


Dave

Victim64

Nice. I have to get one in the mail ASAP! lol

Looks like your max torque is lower though?

Dave B

Yes, the VI manifold seems to have lopped off the two "humps" where I made my higher torque. All I can think is that the area between the bottom of butterfly valve and the runner is causing a slight bit of lower rpm turbulance. I don't I'm the first VI guy to show a slight loss in lowend power. You can't feel it, but it's picked up by the Dynojet.


Dave

BBaker025

iTrader: (1)

Mine should be here in 2 weeks or so!

Chebosto

iTrader: (1)

....

you gained 10hp through out the power band, and only near the end do you gain your '40' hp. and only for about 800rpm

it is a level and nice curve, but in reality it just prevents the loss already occuring in the VQ.

nice gains. but dont be touting that this is a cure all for mad power gains.

this would only be even more beneficial if it actually lifted the overall curve higher.

matt calder

iTrader: (2)

I wonder if getting the VIM extrude honed would provide better gains that the normal intake manifold.

Chebosto

iTrader: (1)

well. claiming 50 hp is a big whopper.

same deal when i claimed 30 from the Gforce ECU from the clayton dyno. no one believed me but the dyno was there.


whatevers.


i claim 120 hp gain cuz i farted and that instant gave enough acceleration that it resulted in 120hp and 134 ft/lb gain for 0.001 seconds.

mtrai760

iTrader: (19)

Yeah, but if you enlarged it, would you have to get custom butterfly's made for the larger path you created? I wonder if anything can be gained by polishing the inside at least? I'll tell in a month or so...

Dave B

Keep dreaming, buddy. Take a closer look at the plot. That's over 50fwhp and 40fwtq gain. Each grid is 20hp/tq. My peak power is now at 6000rpms vs 5400rpms before. More importantly, the power doesn't drop off like an anvil. Techinically it only drops 5fwhp from 6100-6500 rpms. At 6000rpms, I gained 24fwhp and 20fwtq. As the RPMs climb, the difference becomes huge. Sorry (and I can't believe you can't see it), but the VI is gaining me an EXTRA 900rpms of useable and extended power. Every gearhead knows that extending your useable topend by 900rpms will result in a substainal increase in performance both in the 1/4 mile and in the topend. The fact that you can't see it is beyond me. In 1st and 2nd gears, the gains aren't quite as apparant due to the torque multiplication of the gears, but once you get into 3rd, 4th, and 5th gears, accelerating thru 900rpms takes much longer and this is where the gains will be seen and felt.

Your gains with the G-Force were always questionable and the power you gained really wouldn't help much in the 1/4 mile because it did little to help power after 4500rpms. Verified 1/4 mile data backed up the fact that the G-Force ECU did little for performance.


Dave

carnal_c30

iTrader: (38)

wow so technical Cheston hehe

dyno sheet explains the boasting though... its true but it dont mean you'll be running with the SC boys

speedtrip

It's good to see some trends showing in the dyno curves across the different model years. Maybe with another year of learning we will have the optimal set-up for the VIM and a solution to the midrange loss.

Weasel

iTrader: (2)

- Maximize window with dyno plot in it
- hit "Print Screen"
- open graphics program
- create new image the size of your screen resolution (i.e. 1024x768)
- hit Paste (Ctrl+V)



That's the best illustration I've seen of how well this thing really works. Once the rev limiter is bumped up you'll be running it to 7000 in every gear.

Sprint

iTrader: (10)

how is this a shady dyno? Mishmosh made 50 - 60 hp @ high rpms'.. so did Mr. Cranman.. a matter of fact.. everyone who dyno's a VI is almost over 40 fwhp @ 6500 rpms than before..

with the G Force ECU.. you had power gained alright.. but you never messured the 97 ECU vs the 96 G Force ECU for your numbers.. you used the 96 ECU w/o G Force Modification vs 96 G Force ECU.. which was flawed because the 97 ECU was putting out more power than the 96 ECU w/o G Force Modification..

so it may have gained like 15 hp with the 96 ECU w/o G Force Modification vs 96 G Force ECU.. but it only gained like 5 or 6 with 97 ECU vs 96 G Force ECU..

and thats why Chris and everyone was on your **** calling BS

Dave B

Couldn't have said it better and I'm not use to you spitting out valuable information. Where's one of you famous one-liners


Dave

Sprint

iTrader: (10)

right here

Nismo87SE

Here is the real question does a 95-96 owner get the 15whp or the 5-6whp that a 97 owner gets? Either way it is cheaper than a full SS catback (waste of $$) with no noise and better gains period. The ECU should boost the midrange torque back to where it was before the VI was added. While also increasing toppend power alittle too.

Sprint

iTrader: (10)

yeah it gives the 10whp for 95/96's.. it maybe cheaper than a full catback.. but all catbacks give the same hp.. other "ECU" give you better options than this one ..

dwapenyi

iTrader: (3)

Surprised to see you being a skeptic. I'm sure you know it's all about the area under the curve, length times width, or in this case length times height. height (peak power) did not increase, but the length (highest ponits of the HP and TQ lines going across) sure did. It ain't no SC or turbo or NOx, but for NA, it's badass.

DW

Dave B

Amen.

Take 3rd gear acceleration of the VI vs the non-VI manifold for example. With the VI you enter 3rd gear at around 4800rpms assuming you shifted at 6500rpms in 2nd. This means you're riding a HP curve of 160fwhp (4800rpms) to 183fwhp (6500rpms) with peak power (189fwhp) occuring at 6000rpms. Without the VI, you're forced to shift into 3rd at 6200rpms from 2nd gear for optimal acceleration. In 3rd gear and without the VI, you're riding a HP curve of 165fwhp (4500rpms) to 164fwhp (6000rpms) with peak power occuring at 5400rpms. The reason it only goes to 6000rpms in 3rd is because power drops off so much after 5500rpms that shifting at 6000rpms is optimal. I know it's very complicated, but the truth is this, without the VI you're only accelerating in 3rd gear for 1500rpms before you need to shift plus your power drops off like an anvil after 5400rpms. With the VI, you're making a butt-load more power and you get to accelerate for 1700rpms all the while the engine is continuing to make power nearly to redline.

With a 7000rpm redline, you'll be able to enter each gear 500rpms higher which means you'll get to ride an even more powerful HP curve. In 3rd gear with the JWT ECU, you'll enter 3rd at 5300rpms which means you'll ride a curve 178fwhp (5300rpms) to ~180fwhp (7000rpms). The ECU alone will allow you to gain 18fwhp in your acceleration curve


Dave

Lime

yep. Thanks for posting for me, Cheston.

Sprint

iTrader: (10)

don't tell me you agree with what he said?

more useable horsepower at higher rpms is better than lifting the overall curve..

i would rather take 50 fwhp @ 6500 rpms than 10 more hp on an overall curve..

because if you think about it..

say you start with 170 @ 5500 rpms and 125 @ 6500 rpms

with 10 more overall..

you are 180 @ 5500 rpms and 135 @ 6500 rpms..

after 5500 rpms the car still drops off..

with teh VI...

you have 170 @ 5500 rpms and 174 @ 6500 rpms..

so yeah.. your little 10 hp might blow me away for a hot second.. but as soon as i hit top end.. you are toast.. how can you agree with that?

BEJAY1

iTrader: (19)

My dyno verified exactly that max gain. Max +4.6hp/+10tq on a 97. At midrange though @ 4450rpm though it showed +8hp/+11tq.

Padsy

iTrader: (1)

Good Job Dave.

gLok

Has anyone tried the MEVI with boost or spray?

Sprint

iTrader: (10)

MardigrasMax has done both

to be honest with you Kev.. it does an N/A car more good than a boosted car

here come the flames

gLok

Cool i didnt know that.

dwapenyi

iTrader: (3)

Sounds like some people may be afraid of redline, in which case this mod may not be for them. It's not like this is a 1970s domestic motor that if you hit redline, a piston may go flying through the roof It's a VQ baby!! Like my sig says, go to redline with passion

DW