I dont think anyones willing to goto the dyno over a small mod, esp when dyno prices are so expensive, you know you wouldnt go either eddie.. lol

 

Would it be possible to use an X-Terra TB instead of the Pathfinder TB? I searched through the forum but didn't find anything on it. The Xterra's is cable driven and there seems to be alot more availability. But I haven't found any specs on the bore of that TB yet either.

 

Prolly not. The xterra until the 2005 model year used the VG engine, not the VQ.

 

Ok fine, it's not "extensive" tuning. But a tune is a tune, and makes power at all rev-ranges. And when you dyno'd over 200 WHP, that was awesome, seriously. I congratulated you when you first posted it so don't think i'm just a hater. But until now, nobody is faster at the track for having added just a PF TB. If there's no average gain in trap speeds from JUST the PF TB, it's not doing much.

http://forums.maxima.org/showpost.ph...50&postcount=6stock ECU, stock TB, no cutout, etc. It could be said that the only thing those numbers prove is that 00VI > MEVI. While that may be true, it also shows that the stock 3.0 TB is NOT the bottle-neck for making N/A power.

Just to even the playing field, i'll show a dyno of a car with the JWT/MEVI like yours. http://forums.maxima.org/showthread....4&page=1&pp=30
STOCK TB. His mods are listed. Sure he has a 3-angle valve job done and a minimal overbore due to a scratched cylinder wall (the gains from this are negligible since he's using stock pistons), but also consider that his ECU is stock. Again, the stock TB is not the bottle-neck for making n/a power.

I also recall Iron Lung making 215 WHP with stock ECU. Just I/H/E/Cams. Stock TB.

Then of course there's BlackbirdVQ. He has been clean over 220 WHP with stock TB. Sure his mod list is longer than most, but he's still using the stock TB. I'll try to see if i can get him to chime in and post his charts.

Silly me...how could i forget about this one?
http://forums.maxima.org/showthread.php?t=423821
He's making nearly the same HP that you did before you had the S-AFC II tune and exhaust cutout, which was 204 WHP, IIRC. He has stock ECU, and stock TB.
That means you're making more power than he was, sure. But you have other mods as well that have been PROVEN to make power, a tune, and exhaust cut-out. Sorry, but that doesn't conclusively say something about the PF TB. Now if you say that you had a higher trap than him before these two mods, that would be saying something about the PF TB.

 

We're talking about trap speeds here, which are a better indicator of total available power than e.t.'s. Your traps are over 2 MPH's shy of neal's despite the JWT ECU/00VI/PF TB combination. The 00VI known to make much better mid-range torque than the MEVI and better high-RPM torque as well. What was your race weight then?

 

Not to mention 98SEBlackMax just posted in THIS THREAD that he experienced a torque loss compared to stock with the PF TB and 00VI that he had to make up with tuning.

Two things to note:

1. The 00VI is known to make the same, if not more, mid-range torque than the USIM and he recorded a torque LOSS with the pathy TB and port-matched 00VI...read on..

2. His 201 WHP are in-line with others that have a 00VI/JWT ECU combo with stock TB. According to his dyno and the shape of the torque curve, the PF TB added no peak HP and no more area under the curve over the stock TB.

 

and my oil pump also wasnt working that day also
I dynoed without VI and without ecu and put down 197whp . with pathy Tb

 

This is an interesting and informative discussion, with a minimum of flaming. Let's keep it that way, people.

I'll just reiterate my previous position, that a PF TB isn't going to help much, if anything, except for people who are moving a lot more air through the engine than a typical NA Maxima, either through forced induction (excluding nitrous) or a high rev limit.

 

None of the above proved pf tb to over power the stock TB, but none of the above disprove it either. all you said is that who and who made such and such powercurves with stock tb, but none of the pf tb powercurves are compared here. so you can say all you want about this, but you ain't got one running on your car. Until someone runs a before and after dyno with only the throttle as a variant, i think the discussion should be left to those with 3.0's who have the pf tb on their cars.

 

What you're saying is true. But it's more important to prove that it works than to prove that it doesn't. Last i checked, PF TB's aren't cheap, so people need to be informed before they purchase one. Mods like this are guilty until proven innocent.

But i agree. A back-to-back dyno is the only thing that's gonna settle this.

 

Never did I say the TB was the bottleneck of this engine, but I still think it provides gains over stock. That guy has 3whp more than me, and he has these mods over myself:

5 lb flywheel
3 angle valve job
slightly overbored
jwt valve springs
vafc tuned to 13.8-14.0:1 (which IMO is too lean)

he does have a JWT ecu, he just didn't list it in that thread. Search his posts, he has an ecu.


All of that for 3whp over me? I think with a pf TB, he would make more power.

The other dyno list is a quote of someone that saw someone else dyno, no chart.

All I am trying to say is that we don't know for sure if it makes gains, its not worth the dyno money to try it. I feel that it gives gains to someone with most other N/A mods done, but it is definately not a first mod.

 

Unfortunately, dyno proof is the only thing that's gonna settle this. Seat-of-the-pants impressions won't cut it, especially when you're dealing with an item as expensive as a Pathy TB, sometimes costing over $300. I'm just providing a disclaimer to people that are thinking of buying one, which is the point of this thread (if you read the original post).

 

You are correct about the dyno. I was trying to say that a blanket statement about it doing nothing is not true. You are right in that I would tell 99% of people on this board it is not worthwhile to them, but that doesn't mean for someone going all out for power on an internally stock engine, that every little bit won't help. We will probably never have a direct comparison dyno, but I am keeping mine.

 

Fair enough. But also keep in mind that a 1-5 HP increase (if even that) can be considered negligable because 1-5 HP is within the realm of variance on a dyno from run to run. Furthermore, 5 HP will NOT be noticable at the track. I never said it didn't provide power increases, but in the REAL WORLD for all practical purposes these power increases wouldn't change much.

But again, just to clarify, i never said the PF TB provided ZERO gains.

Edit: Just wanted to make another point. Even if it provided some gains, wouldn't it be neutralized by the mid-range loss that it causes? 98SEBlackMax just showed us how he lost mid-range power with the 00VI/PF TB combo with the 00VI port-matched. I compare this to the MEVI, losses at lower RPM, gains at higher RPM, virtually no net acceleration increase. Only difference is, the MEVI made REAL power up top. This is still iffy.

 

yep, nismo is right in various angles of this discussion, too. at first i disagreed because he stepped his foot down and made the claim that pf tb doesn't add horses. but if he never said pf tb provided zero gains, he's got some credit for this one.

look, physcially having the pf tb or not, all we can do is wait for a dyno to break everyone's nuts about this discussion. however, if a before-after dyno is to be conducted, we need to consider this:

on a stock tb, dyno with the manifold as is. then with the pf tb, the manifold must be port matched. if not, air flow turbulence would be a major offset to this mod. i even suspect that those who seem to have lost power with the pf tb is partially due to unported manifolds. also, it is very difficult to do a complete port match because the 4th gen manifold, mevi or stock, is barely able to be ported to a 70mm ID. this is an issue i had to deal with.

i remember at first when i installed the tb, i did feel a loss of power, but i didn't suspect much from the port match issue. i attacked on modifying the intake setup instead. well later on i learned about turbulences and decided to port match the vi and the tb. it worked wonders! i'm not trying to bring a new topic or variant for the mystism about this mod, but my claim for a good throttle response comes from "after port matching"...

 

I guess you didn't have a chance to see the edited portion of my previous post. The dyno chart that 98SEBlackMax posted in this thread was with the 00VI port-matched to the PF TB. He saw losses anyway.

Anyway...thx for your support!!

 

the 00 vi 98seblackmax has on his car came off my 3.0 engine. I sold it to him, so all this dyno talk means nothing to me dynoes vary way to much 1/4 is a better gauge.

Look at all the top runs and what TB there using and you will see most have pathy TB 70mm or 3.5 70mm from max. you will find this to be the case more than not

 

I've said over and over that trap speeds > *. What dynos are good for however are for back-to-back comparisons.

Got a link?

 

krismax has a point, though.

my car runs funny times with this pf tb. i trap at 96-97 consistently with 14.9-15.0 qt's. before i had the tb on, i trap at 93-94mph's with 15.2-15.4 qt's. the runs are under the same mods before and after the tb installs. i have always wondered because i noticed lots of people trapping 97mph's running low 14's. this pf tb shows another significant phenomenon.

however, then i found that my car was off tuned because timing chain came loose, water pump failed, clutch slipped, and knock sensor went out. the only power mod i added after those runs is the splitfire ignition coilpacks, and with all these troubled failures, it did make my mevi engagement alot firmer but still runs slow. best run after splitfire coilpacks was 14.7 at 97mph with pf tb...

 

I just checked your mod list and it's pretty massive. Most people with just I/Y/MEVI/JWT ECU trap 98-101 MPH in the 1/4 mile with stock TB. Still says nothing of the pathy unit. Your traps are sorta below average...

 

well, for a beat up and off tuned car, i think my car is trying hard to take my abuses. but now i've dropped the car at the shop and do some major repairs.

i know it's below average traps, but if you compare my times between the pathy and un-pathy tb's, you'll notice what difference a trap speed i make out of it.

my timing chain has been a little loose during all of those runs. it's just gotten really bad now because it's dangling and knocking the timing chain cover. anyways, all of those problems about my car are being fixed in the shop right now with brand new parts. so i expect good runs soon.

my point is, there is significant difference between the runs. maybe it's just my case, though. i have massive mods like you mentioned, maybe it helped to have the pathy tb over my mods. anyways, i dont' want to claim it this way. dyno's more soundy on this. but my runs are obvious.

 

I have a spare pathy TB and adapter if someone wants to dyno the day i do then i will let them dyno that day with back to back runs with stock TB and pathy....but the main prob is that the IM needs port matching