I've read several of Dave B's posts referring to how many MPH a car gains in the second half of the track as an important component of performance.

My car, running a 9.67 @ 73.7 in the 1/8 ends up with a 15.0 @ 90.15. That's only a gain of just under 17 mph in the second half.

Now, the next fastest 4th Gen auto on the list runs 9.60 @ 74.3 in the 1/8 and finishes with 14.92 @ 93.67. He gains 19.3 mph in the second half.

The only difference in mods between us is a muffler, he has one, I dont. (Otherwise, we both have intake and budget Y-pipe.)

What should I look for that's giving him 2.3 more mph in the second half when our 1/8th mile trap speeds only differ by .6 mph with the same 1/8th ET?

This has me totally stumped!


EDIT: Soory, by "the list" I mean the timeslip list. I'm #20 and he's #17.

http://forums.maximaracing.org/timeslips.php

 

.08 isn't much. It could be due to some very small problem like a dieing o2 or bad spark plug or something. Also, your .6 sec and .6MPH slower in the first 1/8 also. Who cares its less than a tenth. Drop out some weight and you'll have made that up. Take a look at me. I'm running .3seconds slower and yet only 1MPH slower. Its all a toss up of conditions I think. Could be attributed to slight topografic differences at the track which is different in the first 1/8 from the last.

 

Maybe cuz your fat azz is too heavy

 

Get the VI bud!

 

9.932@72.60
15.282@91.54 so thats 18.94 mph for me. Maybe your VI is broken I really dont know the answer but for an auto your max hauls.

 

yeah, my VI is broken.


I dont have the VI.

 

joke hence the slap.......

 

Yea, you must launch that auto very well. Mine ran a 10.2 @ 73mph on the 1/8th on the best run. But then again, I have a ypipe aswell. What is your technique of getting a good 60ft? All I saw was 2.4xx at best.

 

You would be talking about me, lol. One thing to take into consideration is i'm running 225/50's on stock 99 se 5-spoke wheels (should technically be 55's), and i also have the DR mod too. Also, weather condidtions could make a difference in the top end. while you still have the torque down low to pull good 60' times, top end may be getting choked cause of humidity or baro pressure. then again i could be totally wrong , hell my muffler could be giving me more HP, lol.

EDIT: One thing i noticed was that your 60' is better than mine (2.28 to a 2.37)...and that i would be ahead by the 1/8th...i think the DR mod may be a big factor, since my car would shift after the 60'. plus my car bogged a little off the line, i usually run about the same 60' as you...my best being a 2.24 with just the slightest spinage off the line. My runs were at rockingham dragway...i really doubt the lengths are off, since there are alot major sanctioned races there.

 

Keep in mind that suspension mod's might help or harm performance as well. Do you both have the same suspension setup's?

 

don't laugh...it's only temporary, but i have stock struts and slightly chopped SE springs (gave about 1.5in drop in front and 1.5in in back). I'm poor, lol, but they're holding up just fine. I got them from a friend of mine for free when he went to eibachs, so i figured what the hell, u know they ride alittle harsher than my stock gxe springs, but they're still way less "bouncy" than my buddy's eibachs.

 

I wouldn't worry about too much unless you guys are running at the same track and you see that sort of decrepiency. I'm a firm believer in that some tracks are quicker than others. I've experienced with past cars and many on the board experience the same thing. You run in Bama and he runs at "The Rock". I don't want to start any sort of fight with anyone on the board, but I've always felt The Rock seems to give out .2-.3 and 2-3mph higher traps than what most other people with the same mods see. That's just my opinion and that's all I'll say. Disagree and it's fine. I won't argue.

Gaining close to 17mph with an auto without the MEVI/JWT ECU is pretty normal. The MEVI/JWT combo would probably get right around 20mph or so. 5 speeds without the combo typically get around 19mph and with the combo they get around 22mph. Check the 1/4 mile section here and I think you'll see you're right inline with most autos around here.


Dave

 

It's alright, I don't have a problem with cut springs. Some think it's ghetto & some people say why do i want to spend money for only a 1.5" drop. I'm probably gonna chop mine down alittle bit this weekend when I replace my strut bearings because my front looks alittle high on my new wheels. But, just keep in mind that different suspension setup's can effect trap times in the quarter.
If your front end is higher then the rear you might have worse aerodynamic's because your front end is having to push harder against the air. If your front end is to low, you might not get proper weight transfer & so on.

 

Honestly i won't disagree with you on that. Do you think though that the DR mod could be part of the explanation though??

It sits pretty level...i added two coil boosters to each of the rear springs...helped it feel more planted and the bounciness went completely away. they aren't the kind you see for 4x4's they are about the exact size of the unsprung coil gap.

 

I wouldn't be too concerned. I think it depends alot on track and weather. Even when I was a fully modded auto sometimes I only gained 18mph. Sometimes it was higher. I have slips for 79.10mph to 97.16mph, also 79.44mph to 97.5mph. Other days at the track I went from 78mph to 98mph which is a full 20mph. After the 5spd swap I ran it 3 times only, but one time was actually 76.2mph to 99mph which is almost A 23mph gain. I would not be too concerned.

 

Sure, anything is possible. It could also be that you ran in cooler weather or your car is just in a better state of tune. Who knows unless you guys run at the same track though.

I'd love to get all the quick guys from around the country and do a face off at the track. It would level the playing field and it would prove once and for all who's really the quickest.


Dave

 

I'm assuming when you say "fully modded" auto you're talking about the MEVI/JWT combo? I know that BSwithTF (auto GXE) had your same mods and he typically gains around 19mph on average. I think prior to the MEVI he was getting around 17mph.


Dave

 

I did use the DR mod.

It may also be my transmission which is getting old. Even with the DR mod, it sort hangs a little on the 2-3 shift. I'm putting in a newer one before too long, so we'll see if that helps any.

 

I disagree considering my car ran almost identical times and trap speeds at Moorseville dragway (1/8th mile) in similar conditions. The track is 825ft ASL for reference...

 

Yeah, even with the MEVI/JWT I was running 18mph gains sometimes. The small tires that I used could skew the results a little, but most likely not.

 

mzmtg, if your looking for a good auto to build up mine is the perfect candidate. Its got 130K on it with regular maintenance but probably not much life left in it due to my driving style. Its a perfect candidate for a build up like RedMax's or RedMaxPa or RedMax007 or WTF his screen name is. You know who I'm talking about. Anyway, $100+shipping and you have a perfect housing to begin a buildup and keep your car driving during the process.

 

I've got a 70k trans ready to go in when I get the time.

Thanks anyway.

 

Well damn, there goes that argument. Mines basically back from the grave though. I have a tad over 101k on mine now. However, mine snaps into third on the 2-3 pretty hard...when it's wet the steering gets light for a split second, like the tires are spinning ever-so slightly. I wish i could just take a short vid so you could see what i'm talking about...maybe next time im at the track.

Quick question...do you blip the throttle on the 1-2 shift?? from my few times down the track (i have 15 total passes), if i let off the gas when i manually shift into seacond, and then punch it, i get a good little burst of speed at the change. Did it the first time cause i heard of some chirping second w/o the dr mod doing it, and it works pretty good from my experiences.

 

Dont do that w/o the DR mod or a VB mod. You can even hear how bad it goes into the next gear. With the DR mod it quickly goes into the next gear, less heat, less metal being shaved off. When you punch it like that into the next gear its very harsh for the tranny if you're running it stock like that. And I honestly think it makes no difference in time, it may feel faster, but its doing nothing.

 

BEST POST OF 2004

this is a great statement for so many reasons. how about july maybe august im willing to drive.

 

I'll drive up too 7 hours for something to this caliber. Set it up and lets see what happens. I think this is the best idea for a meet I have seen.

Matt

 

get a MEVI

 

Well, Montgomery Motosports Park is a pretty quick track and only 170 ft above sea level.

Only thing is that it's not very centrally located.

 

Beech Bend in Bowling Green, Kentucky is a fairly quick and professional track. It is pretty well centrally located to alot of people. It is about 4-4.5 hours from me. How far is it from you guys?

 

not sure but if all the more serious drag racers on this forum are willing to make the trip I will be more than happy too...

 

Let's get this organized and all start picking the track to meet at.

 

I think we should make it well into the fall so we would have some nice cool air to run in.

 

i would be interested in this too, and i agree with the fall idea too. I know i'm not technically one of the fast maxima's, but for a N/A auto, it looks like i'm pretty fast. I really wanna go up against mzmtg and see how close it really is.

 

I wanna go too. By the fall I should have VI and ypipe on.

 

Ben, you should hoop up the obdII scan stuff and see what your a/f and timing are doing. If you have a KS problem, you should see the timing go all over the place. If you have a lazy 02, you should see the a/f dip down.

 

At WOT his o2 sensors shouldn't affect the power. Open loop operation runs preset a/f ratios. I have had a bad o2 sensor for as long as I've had my car (the previous owner replaced it like 4 times in 3 months and each time the code would come back within a day) and it doesn't seem to affect my performance at all. I suppose I have never run the car in a "normal" state so I really dont have anything to compare it to, but it seems ok to me.

 

My KS is relatively new, about 15k miles old.

 

Oops, missed this post. I am going to have to disagree a little. my times dropped about a tenth or more when i did that. keep in mind i have the DR unplugged all the time. i don't do it because i want to, i do it because i have to. from it being unplugged for like a year the one-two feels like stock shifting wise (bands are getting worn out) and when i do it right, there's no loss of momentum, just a slight surge of speed and the occasional chirp. Don't tell me it's bad for the tranny, believe me i know it is. but i don't go doing it every time it shifts. I've done it like 5 times if that. Now if you have a stock tranny and do it w/o the DR mod, then i agree it's very bad on the tranny. You are essentially forcing the tranny to rev up and slide into gear, thereby wearing the bands at a astronomical rate. i only tried it cause some said that they had gotten their cars to actually chirp second doing it without the DR mod.

 

I am more than willing to drive for this type of meet. The only concern is showing up and only getting 3 runs. If there is enough of us "faster" guys willing to do this then I am in. I just need a month or two advanced notice, and of course the fall would be better because of the temps.

As far as the mph gains on the 2nd 1/8th, I have sometimes only gained 18-19 and sometimes gain 21-22. It depends on the weather and the track.