Hey everyone...As it says, finally had my car on a dyno (did it at Maxus on Saturday since it was so cheap!) and well...I'm a little confused, maybe disappointed with the results. My AFR seems like its in the wrong spot and very uneven. I don't have a tuner for the car, so I can't easily change it either. The guy there was suggesting maybe the MAF is faulty, which I guess I can see. I don't think it's related to the fuel pump or FPR since I'd think that would be more consistent as the RPM goes up. I have an Injen SRI, NWP spacers, VIAS plate, test pipe, custom 2.5" catback, if that helps. Any suggestions are appreciated! Thanks in advance!

http://picasaweb.google.com/11090801...75441294646146

I don't know how to put pictures in the post, sorry!

 

I would dyno the car again. I seen someone else dyno at like 100hp which is clearly wrong after seeing thier track times.

 

That's pretty weird haha. I ran a 15.3@91mph, which clearly sucked. I mean at least my pulls were consistent, but consistently crappy. Maybe because it was hot??

 

yeah the weather will play a huge part in the times and dyno #'s

 

i might have missed it, but is it a 6 speed or auto?

+1 on the weather playing a huge role in those times/numbers

 

I dyno my car yesterday I'm somewhat happy on the results, yet I've seen a 5.5th gen that ran after me got very similar results to my car.

Actually byrdman164 your results are very similar to mine only the graph is different.

 

It's an auto, I forgot to mention. The sheet said around 95 degrees for the run so that definitely doesn't help, but I still feel like the numbers were a little low, and the AFR is totally messed up

 

LMAO!!! that would be me sir... the reason for that 100whp was that when they hooked up the lil clip to cyl 1 they snagged a wire out causing the car to mis... but yes the dyno was terribly off, i ended up dynoing 228whp, and my dyno with just I/H/E was 238whp and i have more mods now lol, i knew it was off but i was like what the heck, ill do it just cause.... here is a question i have for the dyno guru's, whats with that huge dip at 5.25K rpms??? i get the samething and im also auto, but yet kingjames who is also auto doesnt get that... whats the cause for that???

 

What mods are done to your car?

 

the weather is the minor part... the dyno was just pure straight up incorrect, kingjames dynoed a max of 154tq... other than the AFR everything else on the dyno was off by a long shot, who knows the AFR might be wrong too

 

You strike up a good point, if part of the information is wrong, who's to say all of it isnt wrong? I guess Ill have to come up with the money and dyno the car again, just to see...I know my track times were terrible, but Ive also never raced before either so who knows. I checked my fuel trims, and theyre very close to 0%, so I dont really think the MAF is to blame - though I dont know if anyone else had problems that day. And if the MAF is reading incorrectly due to a fault, it can skew things a bit.

 

Dammit. I forgot to give you that can of MAF cleaner today, maybe that woulda helped? I dunno. But it seems that everyone is saying the dyno was off, so maybe your afr isnt messed up but the equipment itself was?

Edit:Looks like GrandHustle beat me to it. hehe

My fuel trims are 0% too *ahem*

 

I really hope they dyno is off - its cheaper that way lol.

Ill get some MAF cleaner tomorrow maybe, if I care that much at the time - the car runs strong and smooth, so who knows. Though I DO have an oiled air filter, maybe some oil contaminated the MAF?

Too bad you didnt bring your car Ryan, I was looking forward to actually beating someone

 

Haha way to update your post...your fuel trims are pretty off, but I bet it still has a better AFR than me...assuming the readings were correct.

Did your P0138 come back after I cleared it?

 

Just 3.5 swap and exhaust thats about it

 

Fixed.

Not yet Im gonna go to Aid Auto or something and pick up some hose (that sounds bad) and just drill the appropriate sized hole in my intake and ditch the breather. *sigh*

 

You should make sure you can seal it, otherwise youre still pulling in unmetered air. I wonder if thats what I need to do, maybe then itll richen up my AFR and Ill make sweet power (yeah, right)

 

Ill just RTV it. I have some left over from installing my spacers. My brother has the equipment to weld aluminum but it's just too thin. meh. It'll look a little ghetto probably but it should work.

 

yea you appearently have more mods than me yet dynoed lower than me... the track times were off due to weather

Give or take a couple degrees


the dyno wasnt off because of weather, it was just incorrect all together, again with just I/H/E, i dynoed 238whp here in MD, and ive added mods since then but this dyno reads 10whp less, yet the 1/4 ET and weather factored in was showing that the car clearly had more than 220's... again just for the simple fact that kingjames (a fully bolted 5.5) dynoed a max of 154wtq should tell you something, we are talking a dynojet that reads lower than a mustang dyno, all this should trigger suspicions... MAf cleaner or whatever wouldnt have helped when i dyno is reading wrong

 

Yeah thats pretty hot haha. Im kinda glad the dyno seems to have been messed up, maybe I shouldve been putting down more. Guess Ill have to find a different dyno and try it all again. The only "good" thing about it is that I realized I want more power Maybe I should get a tuner thing......

 

I found a place in west Babylon, Vinny Tenn Racing. They've got a dynojet there. It's 100/hr w/o AFR and 150/hr w/AFR. That seems kinda high but I've have no clue what "normal" prices are. I would def. meet ya there one night.

 

2002 maxima - ya i also did the dyno on sat i didnt get it a few people said they dyno 30hp better on a diff dyno with same or less mods my car did 210 whp and i thought it would have been . better than that considering i have headers y pipe exhaust intake.

 

ya. a tuner.....

 

a tuner thing lol

 

yeah...bout that...haha...I know nothing about them

 

vafc, safc, emanage, vmanage, UTEC, cipher ect ect ect

 

http://forums.maxima.org/5th-generat...-v-afc-ii.html

http://forums.maxima.org/5th-generat...ng-thread.html

 

^^^ that

 

Yes, all very excellent info thanks...but I think I found the problem. Maybe the AFR readout wasnt 100% at fault.

Im pretty sure my MAF went today

 

Wasn't or hasn't it already been established that the dyno in questions was reading horrifically low?

It wasn't the temperature since the readings posted were corrected, in fact, it might be favorable since the CF was a bit higher due to the conditions.

 

Oh yeah, I'm already over the numbers being low and all...the AFR, whether its right or wrong is still bugging me. I was driving home last night and went to merge and the car fell flat on its face at about 4000rpms and then revved a little more and banged into 2nd. I'm leaning towards the MAF actually being messed up.. I pulled it out to check it and its got some oil on it from the air filter, so I'm gonna try cleaning it and hoping for the best....its the only thing I can think of right now, especially with no codes present or pending. My fuel trims are sometimes around 20 to 25% ST, and LT hovering around 10% both banks. O2 sensors seem to be switching normally, so the only thing I can assume right now is the MAF providing false airflow signals...and the trans banging 2nd is bc the TPS sees the angle of the throttle and assumes a higher load, thus more pressure. Maybe I need to monitor fuel pressure also as rpms increase?

 

Calculated load comes from throttle and MAF reading, nothing to do with fuel pressure, if anything it's line pressure for the tranny banging into 2nd.

 

what still hasnt been explain to me is what could cause that dip in the dyno graph at 5.25K rmps???... mines had the same dip and i thought it was because the AFR started leaning out so i started losing power but even with messing with the VAFC some and bringing my 18.1 AFR to close to a 13.2 that dip was still the same, never changed a bit... somebody care to explain what a auto VQ motor does at 5.25K rpms???

 

i wish that 30whp was across the board for everybody as my car would be dynoing 258whp and im sure im no where close to that... would love to see those numbers though... dont take that 30whp to the head...

 

Are you rocking an SRI? If so, that may be the cause. Myself and Zack342 proved this a while back. The lack of the Helmholtz resonator (in between the TB & MAF) causes this. So if you have a straight pipe in that area, that could be the cause.

 

Well, glad to report that all is well with the MAF. Picked up some MAF cleaner today and sprayed the hell outta the sensor. The wire was dull before, and now it's all shiny. Unplugged the battery to reset the KAM and then drove it and it drives like a champ again. Which makes me happy b/c I don't feel like spending money on a new one.

NmexMAX, the helmholtz resonator is that rubber ribbed piece of tubing right? Stupid question but I just want to be on the same page. I had my injen intake in, but as an SRI. Maybe that also created my dip in the same range as Grand hustle, but by straight pipe I'm assuming you mean no resonator and not literally a straight pipe? Stupid questions but I have to ask anyway

 

The helmholtz is that box that the crankcase ventilation hose is connected to on a stock intake. I think.: /

 

Maybe, I just read a few threads about it and totally forgot why I was reading it haha. I wonder if itll make any difference on my car...

 

it must be the SRI, but what i dont understand is that Kingjames, who also dynoed (auto), has a SRI also and he never got that dip, and there is a few auto that dynoed and never got that dip, other than a CAI (which im not doing) whats the best way of getting rid of that dip, i can actually feel it when i floor it on the highway, you can hear the struggle in the engine to get by in those RPM ranges then all the sudden a more smoother pick up... i thought at one point it was my stock catalytic convertor, but i then changed it out to a gutted stock cat and its the samething... i hate that dip, im trying to get rid of it ASAP

 

Were their mods the same or similar to ours? Ive been having problems with my MAF since Maxus up until today when I cleaned it. Wasnt really looking for a dip today rather than just enjoying making any kind of power over 4000rpms. Ill have to drive it again and look for it, but I put the extension for the CAI back in so I may not even notice it. If their dyno was messed up though maybe it only occurred on random vehicles, or were you referring to other dynos as well?