Mishmosh

iTrader: (3)

1995 SE 5-speed
181.2hp @ 6300rpm, 176.6tq @ 4900rpm


I have:
Variable Intake Manifold (5k rpm set point)
Cattman Y-pipe
Cattman CAI
Greddy Cat-back
PFR6G-11 (one step colder, Courtesy sold me as "stock" replacement, reportedly less HP)

For graphs of my 1st two runs (Dyno001=VI closed, Dyno002=VI open)
Dyno001=valves closed (stock?)
Dyno002=valves open

For spreadsheet comparing all 3 runs (template courtesy of xHypex):
Spreadsheet RPM/HP/TQ
Assuming VI closed roughly approximates stock manifold performance:
peak hp gain = +6.8hp
hp gain @6400rpm = 27hp

Aside: I was thinking redline on my car was 6500 or 6600 rpm but from the dyno, it is clearly 6400rpm. Anyone know why this is? Maybe that's why I often bump into the rev limiter in 1st gear with the shiftlight set to 6200rpm...

kushane

Looking at the spreadsheet, I am curious as to why there is a difference between the "VI Closed" numbers and the "VI-5K" numbers at rpm's less than 5k? In the VI-5k run, if the VI stays closed at less than 5k - shouldn't it pump the same numbers as "VI-closed" ?

Mishmosh

iTrader: (3)

One would think... I don't know what is acceptible margin for error and just pull-to-pull variation. I will say that I was less than impressed with the fan this place used in front of the car but other than that, nothing seemed out of line. In the graph he forgot to print out for me with the 3 pulls shown together, the final pull really did look like the VI-closed up to 5000rpm and VI-opened from 5000rpm on.

Nealoc187

iTrader: (23)

Nice curves... the graph I mean not you

Are you sure the dyno operator didn't just let off the gas at 6400rpm.

breaux124

iTrader: (1)

I'd have to say the variation is so small that it can be attributed to margin of error. Could be temperature differences.

I'm guessing the first run was closed. How long was your car cooling down? Did anything change between your first and third (VI activated) run?

The differences are so small (less than 2hp) that it can easily be attributed to variance in the dyno machine's reading.

JustMaxin96

iTrader: (3)

That curve is very nice cant wait till' I get mine. One question though I have seen people put down 200 lbs. of torque to the wheels w/ no VI and with one no one even comes close..and how are they getting all that torque? Thanks... very impressive!!

breaux124

iTrader: (1)

Most people that have inflated Torque numbers (myself included) come from lower RPMs (look at their dyno curves). It's usually do to shifting into gear, or the dyno machine not calibrating fast enough. It's usually a spike at the beginning of the curve. If it's not, then they just have more power to the wheels somehow.

HP is actually calculated from TQ and RPM.
Pretty sure it's: HP = TQ x RPM x 1/5252

Anachronism

Iansw reported that if the VI was left open the entire run it never gained high RPM power, but that does not seem to be the case with yours. It looks like 5000 rpm or possible a touch higher is the ideal set point. Could activating the switch faster reduce the dip in power on changeover or is this just inherent with the VI?

Isn't the ME/JDM Max rated at 220HP? Why don't we see gains of near 30 HP?

Dave B

On an automatic this is true, but on a 5 speed the operator just mashes the gas. My Max shows 180-193fwtq from 2200-5000rpms. The curve has a slight dip at 3500rpm (180fwtq) and then it shoots back to 190+fwtq.

Dave

Mishmosh

iTrader: (3)

Well, the session went like this:
He did one run. It said peak HP was 86hp and I was about to either bust up crying or bust up laughing (at the minima)... Then he says that, dammit, the dyno was set up previously for a motorcycle so only one wheel was measured. He spent two minutes setting it up and did the 001 run. AFter that was done, I went and zip-tied the valves open. The 002 run proceeded without much rest but the engine was turned off each time. We talked about the curves from both and he commented that Porche has the same variable intake runners that work very well. He said we'll give the car a cool-down so about 4 minutes went by before 003 (with the VI on) took place. Again, the fan used was the kind carpet cleaners use to dry rugs--kind of like a turbine with a flat mouth at the bottom where the air comes out. Seems to me, most of the air flows right underneath the car that way! WTF?

Redline: I specically told him to hit the rev limiter--I told him I thought it was 6600rpms. I even deactivated my shiftlight thinking that might scare him into backing off. If you look at all 3 graphs, it just drops off at the same point--very reproducible. I may have to think JWT ECU now...

VI open: after 5000 rpm, allowing for margin of error, the curve is pretty equivalent to the curve with the VI activated at 5k rpm. Again, with the curves superimposed (no graph given me, but shown to me), the VI-5k looked like the best of both worlds and tracked both fairly accurately aside from the changeover blip (which I believe is also seen in 5th gen dynos).

Dave B

I too am a little concerned as to why everyone with a VI is only getting ~180fwtq while there are some getting 190+fwtq with the stock manifold (me included). I've checked the dyno forum and it looks like "most" are getting 180-185fwtq with the stock manifold. We do need to keep in mind that the VI doesn't gain very much "peak" power, instead it allows to the powerband to be longer and much more broad which is far more important than adding peak power. The longer the power holds on, the longer you will accelerate, which means a drop in ET and added MPH. All dynos will show different numbers and some cars are slightly stronger than others. I doubt the VI takes away power from idle-5000rpms and if it did, most guys would have said they had experienced a loss of torque. Anyways, I can't wait till I get my VI and you know I will post my numbers and timeslips ASAP.


Dave

Mishmosh

iTrader: (3)

They also do not have emissions controls. No O2 sensors. Probably not the restrictive Y-pipe or even a catalytic convertor that we have. The wrong variable intake that **** RB sent me was used yet the port to the EGR was capped--safe to say no EGR system over there neither. I think if you add all that up, you might get your 30hp.

My numbers are merely average. Even without a VI, there are people here putting up 180+ fwhp with I/E and sometimes ECU. Plus, I'm wondering if the HP rating used in the ME is SAE or english.

Mishmosh

iTrader: (3)

Yeah, I can't wait to see what some of you who have dyno'd your cars already and hit the track on occasion do with the VI. This is definitely an interesting time for sure!

NmexMAX

iTrader: (22)

Mr. Cranmans are coming from Japan, doesn't Japan have more restricitve emission controls than we do?

Mishmosh

iTrader: (3)

Well, most parts are sourced from Japan but I'm not sure that the VI is a JDM part... at least for the larger ported "38U" intake manifold. As far as I have read here, these are only found in the middle east, no?

speedtrip

My dyno operator has a h!ll of a time hooking up my max to their dyno computer. The first two times redline was 6500 then the last time it was 6400 rpm. I would say it's in their machine.

I'm curious as to what effect, if any, the colder plugs are having on your max. Your making more torque than I am at 6100+ rpms. Could it be the colder plugs are more effecient at that higher rpm and temperature? The rpm that our peak torque values occur at are markedly different. Mine's at 3300 rpm and your's is at 4900 rpm
yet the rpm our peak hp arrive at is the same.

Looking at the shape of your dyno and mine the evidence is mounting that the ecu is cutting in on this dance. I need to dyno agian to see what effects the carsound cat and warpspeed b-pipe had.

The information you have provided is much appreciated!!

speedtrip

I had the same exact dip that Mishmosh has when I dynoed with my CAI. When I switched to the hybrid intake the dip was still present but not as severe. I think it's just the nature of the manifold.

As to making the changover faster I don't know how it would be done. I would assume all the electrical connections would happen instantaneously. I have a pretty big vacuum canister with plenty of suck so that's not the solution. The one thing I could see having a influence is the length of the hose between the solenoid and actuator arm itself.

Kevin Wong

There is a margin of error from the tach on the cluster and the actual engine speed. When I was getting my smog checked, they pulled the engine speed off the engine and not the cluster instrument...there was like a 300 RPM difference or something. Something on my sister's 90 Accord.

As far as power gains go, do you think it might have to do with the CA/NLEV or Fed-spec issue. Apparently SC'd people are missing quite a lot of power on their cali-spec'd Maximas.

Mishmosh

iTrader: (3)

Not really. While a lot of 99+'s sold in other states are Cali-spec'd, I don't think there was much of that going on for the earlier years. I for one know definitely that I have a fed-spec. Still, people have some pretty great numbers without the VI (180+ even 190+ fwhp) and I'm wondering if these people will maintain, gain, or even LOSE peak HP and TQ. Of course the main benefit of the VI is the extended power band but still peak numbers are interesting if only to see if we can account for the higher HP figures of stock middle east maxima's.

Dave B

We'll see how it goes on the dyno and the track. I'd trade off a little tq for an extra 1200rpms of useable acceleration. You can be certain I'll test my VI at the track as soon as it's installed and operating correctly. I even went out to the track in hot weather last week just so I'd have baseline in hot weather with my current setup (non-VI) for which I compare with the VI installed and running in similiar hot weather in 2-3 weeks.

As for some 4th gen Vq 5 speeds not making the same power as others, I suggest some of you venture to the Dyno Forum. You'll see that some of the lower powered VQs are actually some of the quickest and fastest. I think that clearly shows that a dyno is a measuring tool for your particular car and that you should dyno on the same machine everytime or you'll get skewed numbers and introduce variance and bias.


Dave

iansw

iTrader: (7)

I don't recall ever saying that.

My Dyno run with the MEVI open lost hp and tq at lower RPMs, then the curve leveled out at exactly 5000 just like his.

And my MEVI's are coming from Japan, just like Cranman's, I'm just forced to use a middle man, which is why I had to charge a few $$$ more.

IanS

MaximaPower

iTrader: (3)

weird.
didn't someone jus dyno at around 178hp with intake, new budget ypipe, catback or somethign liek that...can't remember

i'd expect more hp and torque with all those mods u have

Toolrocks

iTrader: (1)

Don't have anything to add but I am awaiting the arrival of my VI and I too have a 95 SE. Mine is FED spec is yours Mishmosh? Also, I was noticing your car doesn't have the dip in the torque curve that mine does. I can't post my dyno but my torque curve spikes at 3300 and then goes into a valley until 3800 when it builds back up to a broader curve. My #'s are Max Hp 177.4 and Max Tq 186.3 Those are corrected #s, are yours?
For comparison, at the dyno I had a Stillen pop and WSP y that was all. Can't wait to get mine and see others track times.

iansw

iTrader: (7)

Peak HP isn't what the MEVI is about.

A Maxima with no MEVI and 190 peak hp will definately lose to a car with a MEVI and 175 peak using the same shift points.

Just look at the curve. It's beautiful!

IanS

Anachronism

I couldn't find the post I was talking about (there are lots of long VI threads) but I guess I must of misunderstood you Sorry.

Mishmosh

iTrader: (3)

Yeah. I have a FED-spec max. Most 4th gen dyno's I've seen have a tq peak at 3300 or so and then again above 4500rpm. I believe the numbers are SAE corrected but the correction factor is 1.02 anyways. I just wish I had a dyno with the stock manifold on for better comparison. Although my peak torque is low, I think my numbers are reasonable for what I have.

Dave B

Your spark plugs could definately be hurting you too. I would consider changing them to OEM range. I VQ is very sensitive to spark plug variations, more so than any other motor I've dealt with.


Dave

MaximaPower

iTrader: (3)

ahhhh..now i see

thanks for clearing that up for me

Nealoc187

iTrader: (23)

I dyno'd 182hp and 189tq with JWT POP and Cattman SS Ypipe. Of course I plan on doing an "after" dyno with the MEVI, but my numbers won't mean alot to most people because in addition to the MEVI, I will have JWT ECU, UDP (thanks Jason) and WSP Test Pipe. I plan on doing a "tuning session" which is $80 for an hour worth of dyno time. I'll do runs with the VI functioning, and non functioning, and with stock ECU vs JWT ECU, and perhaps G-Force ECU if BEJAY1 is there, we've been planning on trying out eachother's ECUs to quantify the differences between JWT and G-force.

These tests should yeild some good info.

Dave B

Sweet. I'm assuming you're expecting your VI around the same time I am (next week sometime?).


Dave

Nismo87SE

You know your dyno almost mirror's Cattman's orginal dyno when he first made a Ypipe. His dyno was 161whp/174wtq stock and 181whp/191wtq with the Ypipe and open airbox. The ECU + udp should put you in the 198-206tq range.

Mishmosh

iTrader: (3)

I hope you can test out some RPM switchover settings other than 5k. From the looks of it, I think 5200 looks like a decent setting. In any case, that is sure a lot of stuff changed. Pretty exciting!

Toolrocks

iTrader: (1)

Really eager to see the results too. I have been debating for a while now, on whether or not I want to get the UPRD/Gtech ECU. I have a 95 and supposedly that year is the easiest to get power out of an ECU . Nealoc - the test pipe, is it the bigger diameter tubing meant for S/C, Turboed, or NOSed cars or is it something different? Thanks.

Nealoc187

iTrader: (23)

My test pipe is 2.5" diameter. It's $25 from WSP and has an 02 bung already. I didn't notice any gains from it, if there are gains they are small. I purchased it because I figured I had a fouled cat from running with a bad 02 sensor for a year and a half.

Anachronism

I found it --

http://forums.maxima.org/showthread....hreadid=121239

I took this to mean if the VI was opened early it never got back to the same power level as opening it at 5000 RPM. Again I guess I just misunderstood.

redmaxpa007

iTrader: (21)

ok.. soooooooooooooooooooooooooooooooooooo



if you did not hook up a switch to turn on the MEVI at whatever rpm.. and you left them always open...



what would you curve be?

what would it hurt to leave it open all the time??

i am misunderstanding a lot about this.. i thought i understood, but i think i am confused..

Anachronism

The spreadsheet mishmosh posted has a run with the VI open the entire time, it loses about 10-12 hp thru most of the RPM range compared to the VI closed and VI switched at 5000 RPM. But with the VI left open the entire run it matches the VI switched at 5k run from 5100 RPM up.

It looks like the VI open (and VI switched at 5K) does not start making more power than VI closed until about 5300-5400 RPM, I wonder if there would be any benifit to raising the changeove to 5200 or so. Or the difference might be to small to worry about

speedtrip

I don't have a dyno to back up what I am saying, this is just my personal expereince when I test drove my max with the VI valves open all the time. Accelerating from standstill at WOT, I could feel a low end loss, mid-range felt soft, and high end would pull as though the VI was working properly (i.e. valves opening at 5k rpm). If I was driving normally, say at a 1/4 throttle, or even downshifted, and then mashed the gas I had no power. The acceleration was similiar to flooring the throttle at 30mph in 5th gear.

There is no reason to leave the valves open all the time. It will only hurt performance.

redmaxpa007

iTrader: (21)

thank you both


hook it up to a switch.. gotcha..

Mishmosh

iTrader: (3)

This is what I was thinking also--I wish I got in another run at 5200rpm. It's just a shame that without the raised redline, the time the valves are open is rather short-lived. Too bad there is not an easy way to raise the rev limiter without paying $650 for an ECU upgrade to eek out that extra 500 rpm.