beemreatr

Are these the biggest waist of money or what? has anyone with one noticed any difference since install? if I didn't watch the mechanic I would have thought he ripped me off and kept the thing!

maxgsxr1

i installed the pulley on my car and noticed a differance maybe 3-5 days later. seems to pull harder.......

RastaManMax

iTrader: (5)

Yes, they definately are the biggest waste of money. They yield higher trap speeds, but slower 1/4 mile times

punkdork

And we know there is nothing else to life but the 1/4 mile.

UMD_MaxSE

iTrader: (1)

decent mod after y-pipe/intake... revs up quicker... you won't feel anything earth-shattering, but it's not a bad mod.

BigDogJonx

iTrader: (7)

Agreed. I dont see how it lowers your 1/4 mile times. I dont believe that. The revs getting up there quicker cannot affect 1/4 mile times in the negative area.

Dixit

theMax

its true! I forget who, but it happened to a few folks here this summer. faster traps, slower times???? I don;t understand it but it was true.

Maybe some traction problems due to increaed lowend?

theMax

and I forgot...that was about the same time people reported LOWER HP when they dynod after the UDP on a 5th gen.

Seems to be a better mod for 4th gen

BigDogJonx

iTrader: (7)

Actually you got it backwards, alot of 4th gen people reported lower HP on the dyno after the install.

Dixit

radpp16

I got one, it works. then you get used to it, and it feels like you never had it just like every other MOD, then you want a Y-Pipe, then you want a supercharger and then you die
Roger

MarkG

What type of performance increase were you expecting? paint peeling off the car from the extreme heat generated by the friction caused by the supersonic speeds you probably expected to achieve? I have a UR pulley havent installed it yet. When I do minor mods like a pulley I dont expect to need a pilots license to drive my car.

kit99bar

I'm thinking of getting an UR pulley set also

do tell us about why some people think the pulley's cause loss of power?

theMax

Its not THINK it has been seen on dynos and at the track

Well I think that is a bit general, but SOME people have reported lower Dyno HP and slower 1/4 mile times with the UR pulley.

My opinion is that the pulley gains a smaller amount of HP than the normal variations in 1/4 mile times and dyno results.

I still would get one but not until I had a y, intake...

NJ_MAX2000

Such sarcasm...I love it

Sonic

Changing EVERY pulley will make the car noticably faster, but only replacing one is kinda dumb.

theMax

what is the advantage of increasing your rpms? Better low end? If so will it sacrifice highend by shifting the HP curve?

Sonic

Lets think of this. The engine can ONLY rev as fast as the transmission is turning, correct? The transmission can ONLY turn if it is turning the axles, which in turn are attached to the wheels. When people say 'the engine revs faster', that means you HAVE to be accelerating faster, and yet, the best we have seen from a UDP is what, a .2 second decrease in the 1/4? Is ANYONE going to tell me that you can feel a .2 second difference in a 14+ second run? Sounds like BS to me.

Sonic

Quansung isn't killing me.

Sonic

WTF are you talking about? Island Dragway? Yes, I ran a 15.6 against Deezo, but what were my other two times that day? 15.4s. EVVERYONE ended up running slower on that last run. Oh, and in case you didn't notice, I still had a faster time than him.

I had BRAND NEW tires on that day, that had a total of What, 1/4 mile before I started dragging that day? Even at the third run, they still had less than 2 miles on them.

I have run MANY here, as you well know, and my car is DEFINITELY a highway monster. No one will disagree with that. No one.

Sonic

I agree.

ohboiya

iTrader: (3)

so bloody true ... .. but after the S/C ... u win the lottery .. buy an M5 to accompany your new Lotus ... in every colour ..






















then I woke up ...

Dave B

Here's my UDP data Before I had installed my UDP, my best trap speed was 94.01mph with most traps in the 93mph range. My best et was a 14.73@94mph. My runs that netted me lots of 14.7-14.8s at 93-94mph was in 40-60 degree weather. Late last summer I installed the UDP. Unfortunately the weather wasn't great since it was late summer/early fall. My best et with the UDP was a 14.75@95mph with a worse 60 foot than my 14.73 run. We're talking 0.02 seconds difference and in much warmer 70-80 degree weather!!!! With the UDP, my trap speeds have consistently been in the 94-95mph range with my best trap speed being 95.5mph. In my eyes, trap speed is a clear indicator of added hp. ET is just how well you put the power downto the ground. If your traps go up, you've got more power. It's as simple as that. I plan getting my car dynoed this weekend if the weather can hold just for once (I've tried dynoing for the past 6 Saturdays, all of which had rain or snow). I was planning to go to the track today, but due to our infamous ice storm, I've been cleaning up. I'm going to the track next weekend. I plan on running my best ets because I have yet to make any passes with the UDP in anything cooler than 75 degrees.

I think the UDP is a great mod once you've done the intake, exhaust, and Y-pipe. It's not a earth shattering mod, but none of the NA mods for the Max are earth shattering.


Dave

Dave B

I still don't understand how you could pull on a lot of these guys when you're trap speeds are significantly lower than theirs. Don't you trap out at 89mph or something, but you were able to pull on Sprint who trapped out at 93mph?

Dave

Sonic

90.7. BTW, how? Dunno, but anyone that I've ever driven with can attest to it (and that's a good 15 Maxima people). The car comes to life after 40 all the way up to about 125.

You also have to pick the right situations. I usually pick speeds right near a mandatory shift for the 5 speeds, that allows for me to get the jump, and once I have it, I usually don't lose it.

maxfreak_98

Here's my input:

I had my pulley installed sometime last year and the car redynoed, which showed a gain of 7hp & 8 lbs/ft of torque. Now before everyone jumps on me about this I also had the plugs and fuel filter changed before the second dyno, so the increase "could" have been from that alone.

This past weekend was my first visit to the track since the pulley install. The weather was horrible! Temperature in the 70's, humidity around 90% , dew point in the 60's. The track is at sea level and was in excellent condition. I pulled my best 60' ever.

My previous best w/o the pulley was:
60' - 2.238
1/8 - 9.535 @74.99
1000 - N/A
1/4 - 14.735 @94.1
(temp. in the 60's fairly low humidity)

W/pulley
(1st run-shifted to fourth gear @6K)
60' - 2.271
330 - 6.345
1/8 - 9.705 @73.42
1000 - 12.590
1/4 - 15.045 @91.25

(2nd run)
60' - 2.135
330 - 6.150
1/8 - 9.485 @73.98
1000 - 12.346
1/4 - 14.75 @93.09

(3rd run)
60' - 2.246
330 - 6.272
1/8 - 9.602 @73.95
1000 - 12.461
1/4 - 14.860 @93.26

I shift at redline in first, 6K in second, and held third in all runs except the first. Looks like my car likes to stay in third. I'm also going to try red-lining each gear next time. Just gotta get some cooler weather down here!

A friend of mine with a 5th gen (max_gator) has defintely lost some top end power with his pulley. He's going to take it off very soon and see if indeed the pulley is the culprit.

Terry
__________________________________________________ _________________
98 SE/ 5 speed/ CAI/ UDP/ Stillen Y pipe/ RT cat/ Courtesy B pipe/ Stock muffler
FSTB/RSB/ Clear front bumper lenses/ Clear tails

Dave B

I think humidity is more of a killer than temp. With humidity, there's even less O2 in the air alongwith lots of water, not good for performance.

I think you should be shifting a little higher in 2nd, something like 6200. It's up to you if you want to hold 3rd, but my computed numbers show that when I hold 3rd and I'm going thru the traps, I'm only making 145fwhp. If I grab 4th at around 5900-6000, I'm going thru the traps with 170fwhp. I've always run my best shifting 4th.


Dave

Max_Gator

Terry had some great highway runs and kicked my butt on the track. (Of course on the hwy runs I had some "extra weight - but not on the track.)

Best I ran on the track WITH A 2.194 60' time - was 15.06. Pitiful. My trap speed was consistently low 91mph. Unbelieveable. With a 2.194, I shoulda been 14.6-14.7. Trap speed shoulda been around 95-96. That is what I've consistently run before. SO. . .

I TOOK OFF THE UDP on Sunday. Guess what - I still have the same problem. Car feels flat from about 5800-redline. So, something else is the culprit - I think.

Mechanic suggested the fuel filter - but it is in the trunk and supposed to be maint. free.

I previously had a problem with stalling/wanting to stall after hard acceleration followed by clutching and braking. I thought I had fixed it when I took off my intake and cleaned the filter, since it seemed to disappear. But after resetting my ECU last night - its baaack. I'm thinking its related.

So far, the only things I can think of are:
faulty intake runner changeover - see my dyno below - power falls off beginning at intake runner changeover.

fuel filter

the non-nissan gas cap I have

02 Sensor

anyone have any guesses?

MarkG

medic,

It doesnt appear to me that anyone is arguing about UDP performance just merely discussing the issue.
Everyone poster has an opininion about UDP gains or loses and I find it interesting. You seem very upset that folks are just speaking their minds. Maybe your colon is somewhat stressed and causes you to lash out at people....may I suggest some Metamucil? Its gentle yet effective.

Sonic

And you are????? I was asked a question by Dave B and Hogan. I answered it. If you don't like the answer, oh well suck for you. I do here the ignore list works.

Max_Gator

I apparently created a lot of the problem. Just as I did when I first got my max, I've tried to dyno changes to see what the gains are from each then published it on the board.

I personally like to have that kind of info when making a mod.

I tried to do the same with UDP. Unfortunately, it just made things more confusing since it appears that I have a problem that was not caused by the UDP but which I attributed to it.

If anyone here had actually done a before and after dyno of a UDP (aside from my f'd up one) then we might have a better answer.

As for the UDP theory, it in theory does not create more hp - just makes more available to the wheels by reducing that lost at the crank. Simple as that. Just go read the UR site.

By the way, for whoever said it - .2 is a HUGE gain in the 1/4 mile.