Dave B

Today was DYNO day in Kansas City. The cars:

My Maxima 96 5 speed (y-pipe, UDP, HKS intake, B-pipe, VI)
BSwithTF 95 auto GXE (y-pipe, CAI, catback, JWT ECU, VI)
Guido 95 GLE (mandrel WSP y-pipe)
Soon2BMax 95 SE 5 speed (y-pipe, intake, catback)
SER Spec-V (hybrid intake)
ShortChaz 02 G35 (stock)

My prior best run pre-VI was 182.2fwhp (5400rpms) and 192.1fwtq (4500rpms) with everything, but the VI. Now keep in mind my RPM switch crapped out, so I've got the VI wired via a toggle switch. We strap the car on the dyno, engine decently cool, outside air in the low 70s. We start the run in 4th and I flip the switch at a tach indicated 4900rpms. DOH!! Too early!!! I fubar'd both the HP and TQ curves which caused a severe 10fwhp and 10fwtq drop in power at 4700 and recovery by 5100rpms. Max power was 187.4fwhp (6000rpms) and 183.2fwtq (4600rpms). The HP and TQ carried nearly STRAIGHT to the 6500rpm redline (183fwhp & 151fwtq).

We let the car cool down and I decided to delay the switchover till an indicated 5300rpms or so. We start the run and I hit the toggle at 5300rpms. The chart came up on the screen and the curves were flat out perfect and linear. Switchover occured at 5100rpms with max power of 188.7fwhp (6000rpms) and 184.7fwtq (4600rpms). Everyone got a kick out of hearing the tone change at the switchover.

So here are the facts, I gained ~6-7fwhp in peak and lost ~8fwtq in peak The loss of torque is a bit disappointing, but my torque curve is significantly flatter (damn near as flat as Kansas). I actually gained 2-4fwhp and tq from 2100-3800rpms, but from 3900-4400rpms, I lost ~10fwtq and 10fwhp. Before the VI, my TQ curve had two significant bumps. One occured from 3200-3700rpms and then again from 4300-4600rpms. Within both these bumps is where I had substainial gains in torque. Now with the VI the first bump is less apparent and the 2nd bump is gone. Pretty much TQ stays at 170fwtq from 2100rpms to 5800rpms. Overall, my average TQ is actually higher.

Here's the real important stuff, before the VI, HP at 6500rpms was 130fwhp and 105fwtq. Now I'm at 183fwhp and 151fwtq at 6500rpms. Ummmmm.....that's a gain of 53fwhp and 46fwtq!!!!! What's amazing is that the substainial gain in HP isn't really dropping at all unless you call a 5fwhp drop from 6000-6500rpms a serious drop. I can't wait to get the JWT ECU and take even more advantage of this system.

BSwithTF (Travis) did a run with the VI off and then one run with it on (5000rpm switch over). I don't know the exact numbers, but he ended up gaining nearly 16fwhp and tq in peak power and nearly as much power as I did ultimately. That JWT ECU really must take advantage of this setup. His ending numbers were something like 181fwhp and 171fwtq. I'm sure he'll post later tonight.

Guido (Dave) is a tester for WSP's parts and today he was testing the advantage of the WSP mandrel y-pipe vs the non-mandrel y-pipe (dynoed). The numbers speak for themselves, the mandrel bent y-pipe gained NOTHING in peak power and only a couple HP and TQ after 5400rpms. I believe his numbers were 162fwhp and 166fwtq. I'm sure he'll post later.

Soon2BMax (Trevor) made a healthy 178fwhp and 190fwtq. His HP and TQ curves looked exactly my old curves with the two bumps. Very wierd indeed. Comparing dynocharts (His vs my non-VI), it looks like the UDP was good for ~4-5fwhp and fwtq.

The Spec V (John) with just a hybrid intake put down 147fwhp and 150fwtq. The switchover at 5000rpms on Spec V sounds EXACTLY like a Honda entering the big cam. It's loud. Then we decided to simply point his intake straight up out of the engine and away from the battery just for fun. All of a sudden he gained serious TQ and HP from 2000-5000rpms. Something along the lines of 10-12fwhp and TQ. We were impressed.

ShortChaz (Charles) rolled in his G35, bonestock, with 2000 miles. The car was having problems wanting to downshift into 3rd. Then we tried to do the run in 3rd, but the tach signal was getting screwed up. Anyways, he ended up making 216rwhp with TQ being 345rwtq. The TQ is so high because of shift during the run, but the HP is pretty accurated.

That's all for now.



Dave

Soon2BMaxed

i need nAWWS! the big ones!




Trevor

BSwithTF

iTrader: (8)

Like Dave said I did one run off, one run on. My numbers went like this:

Off: 168.3 fwhp // 179.0 tq
On : 183.9 fwhp // 181.1 tq

He dropped off at 6800 both times. With the VI off I was only hitting 138.6 hp at 6800, but with the VI turned on I was hitting 176.3 hp. Thats 37.7 fwhp gain on the top end!!! My horsepower peaks at 6k now instead of 5400.

Bottom line, I gained 15.6 fwhp & 2.1 ft/lbs. tq with the VI. I was expecting to see the line carry on through redline but I never thought it'd keep climbing like it did. I was VERY happy.

xHypex

iTrader: (1)

How about some scans
-hype

Mishmosh

iTrader: (3)

Damn dude! You're putting down better numbers than me with the 5-speed! Congrats... I gotta get the JWT and see if I get similar benefit.

BSwithTF

iTrader: (8)

My old scanner doesn't work on my new computer with XP. I'll try to get them up somehow though. It's wesome to see the horsepower line continue to climb rather than falling on it's face.

Dave B

I'm gonna try and get my scanner to work also. Unfortunately when I changed computers, I think I lost my scanner program.

Dave

Nismo87SE

All of us cartest users must have dyno charts to input . The VI must really make the car a highway screamer.

Kenneth

iTrader: (8)

wow guys, what a meet! NICE to see the huge post in the midwest forum turn into a great dyno day!

bswith and dave : run those VI-equipped things, for track times....

Mr Cranman

iTrader: (1)

That is awesome guys. Isn't nice to know that the dyno butt 2000 doesn't lie. So, the runners must be just slight shorter like suggested before this just verifies it, with other people see the tq number lower by a few. But, the gain is definitely worth it. That is an incredible gain I might add Dave B...Same with you BSwithTF. So, overall you guys were definitely satisified with your numbers???


-John

Dave B

Here's a plot of my pre-VI dyno best vs my best with the VI yesterday:

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

Since I can't get my scanner to work, I inputed the data into a spreadsheet and graphed it. The numbers speak for themselves. You can also see the much smoother power and the drop in torque.

Both Travis and myself have run at the track with our VIs. Travis ran a 15.01@92mph in 90 degree weather and I ran a 14.9@95mph in 90 degree weather. Unfortunately for me, I realized my VI has only been activating in 1st and sometimes 2nd due to a faulty RPM switch.


Dave

maximamoose

Here's the real important stuff, before the VI, HP at 6500rpms was 130fwhp and 105fwtq. Now I'm at 183fwhp and 151fwtq at 6500rpms. Ummmmm.....that's a gain of 53fwhp and 46fwtq!!!!! What's amazing is that the substainial gain in HP isn't really dropping at all unless you call a 5fwhp drop from 6000-6500rpms a serious drop. I can't wait to get the JWT ECU and take even more advantage of this system.

Maybe it's just that i am a dumbsh!t, but how does the max dyno at 130? i know that stock hp is 190, but i don't understand how you could lose 60 hp? can someone inform me?

tmkforever

I think he means with the VI installed but turned off.

maximamoose

alright, but i don't understand how the VI is that restrictive? like i said, i don't understand all of this, but i am trying to! i have a vi on the way, and i want to know all the pros/cons of it! i read pretty much every post on VI, but i don't understand how it could affect hp that negatively just by being installed?

tmkforever

This has been answered, I'm not sure in which post, but I've read it before. It has to do with the length of the runners and air resonance. Basically. with the VI turned off, the short-length runners are being used all the time and they hurt low-end power. That's why the VI switches from the long runners at low RPMs to the shorter pathways at high RPM. Or something like that....

BSwithTF

iTrader: (8)

Normally, the maxima puts out it's best power around 5000-5200. After that, it falls on it face due to restrictions with the stock manifold. On my car the HP drops from 167.7 at 5400 to 138.6 at 6800. But with the VI, I make 183.9 at 6000 and it only drops to 176.3 at 6800. It allows you to keep power throughout the rpms instead of losing power from 5200 on to redline.

xHypex

iTrader: (1)

To understand the dynos you have to understand how cars are rated.

HP is an equation of torque; HP = (torque * rpm)/5252
The numbers you hear most of the time (190hp) refers to the peak horsepower measured at the flywheel not the wheels. The peak torque of 205 ft/lbs. is also measured at the flywheel.

Dyno graphs show the power of the engine at all rpms, so the torque numbers vary through different powerbands. That's why you hear people talking about wanting a flat torque curve; it would continue to increase horsepower because the torque and rpms are both increasing.
-hype

Dave B

130fwhp and 105fwtq were my dyno numbers at 6500rpms with my stock manifold. My peak HP power of 182fwhp occured around 5400rpms and torque was 192fwtq at 4500rpms. Now with the variable intake manifold my car is making peak power of 189fwhp @6000rpms and peak torque of 186fwtq @4500rpms. My HP power barely falls of at 6500rpms (183fwhp). Simply look at the dyno graph I posted of before and after and you'll see the huge amount of performance gained from this manifold. Technically speaking, my car is now rated at ~228hp and 224 ft/lbs of torque at the flywell. So I've pretty much added 40hp and 20ft/lbs of torque over stock with a VI, Y-pipe, b-pipe, UDP, and intake.

The JWT ECU should give me back some midrange power from 3500-5200rpms which will be nice. Even better will be the extended redline.


Dave

Kenneth

iTrader: (8)

but did you dyno with a faulty RPM swtich? oh yeah, thanks for clarification.

dwapenyi

iTrader: (3)

He dynoed with a much more reliable and technologically advanced switch, himself

DW