Dave B

A few Fridays ago I went to the track and ran some decent ets (14.8-14.9) with pretty high mphs. Out of my 7 runs, 6 were at or above 95mph. One run was was only a 15.0@93mph and all I did differently was wind out 2nd and 3rd to redline with no shift to 4th. This clearly proved to me, once again, that shifting to 4th and lower shift points are needed for a 4th gen VQ. After dynoing my car earlier in the year and finding where the torque curve occured and fell off, I was able to multiply out the best shift points for a modded 4th gen VQ 5 speed (y-pipe, b-pipe, intake). This is what I found to be the best shift points:

1-2 6600 (redline)
2-3 6300
3-4 6100

It should be noted that these numbers are as indicatedd by the tachometer which is 200-400 rpms off depending on gear. I've experimented with winding out all gears, not shifting to 4th, etc, and I've found that my best ets and especially mph come when I shift to 4th with the specified shift rpms. Seeing that the 4th gen VQ doesn't breath well past 5600rpms, but makes decent low end and mid range torque, earlier shifts are needed in the upper gears. Winding out 2nd and 3rd to redline puts you well past torque peak and won't let you accelerate as strong when you enter the next car. On each shift, you want to be entering the gear right before torque peak and ride the HP powerband.



Dave

2ndMAX

Once again, thanks for your wealth of knowledge. I'm gonna definitely keep this in mind when racing 1/4 or street. I'm always looking for an advantage. At first I thought UDP was a waste of time, but more and more I'm beginning to consider it.

madmax2k

Good info Dave. From the 4th gen dyno plots Ive seen around here, the same seems to be true.

For me (5th gen), its easy. I just wind it out until the rev limit. I noted that if I shifted around 6000 rpm instead of 6500, Id lose about 0.2 second.

ejj

iTrader: (5)

4th for me really isn't an option. I'll hit the rev-limiter in 3rd before I cross the line.

Last time I was out I tried shifting to 4th early (5800) and was .2s slower and 2mph slower. I found that taking 3rd close to the redline gave me the best results.

Nismo87SE

Given the wide ratios of the automagics and the fact that their tachs are just as inaccurate. What would be the best shift points? Even though its only 2 shifts, cartest says that 1-2 should be at 6400rpm and the 2-3 at 6100rpm. Since the stock tach is off, this means 1st gear should be run close to fuel cut. While the 2-3 should happen right at 6300-6400rpm as indicated on the tach.

Sprint

iTrader: (10)

hmm.. you are shifting too late...

you are probably shifting at 6300 rpms and above ...

if you are hitting 95 mph traps.. you should be shifting in 4th.. what is your shift points?

Nealoc187

iTrader: (23)

an unmodded 4th gen breathes even worse above 5600 or so correct? so unmodded guys should shift a few hundred rpms sooner i'd assume. my shift points on my 14.872 run were redline, 6300, 6100. I have yet to see a dyno plot of a TOTALLY stock 4th gen, though i have seen one with just an intake.

Also, are the RPM readings on a dyno plot actual or indicated... I assume actual.

Dave B

Try taking 3rd to an indicated 6100rpms and then shifting. Winding out 3rd close to redline won't do much because you'll be shifting to 4th just short of the finish line. When I grab 4th, I've still got a few hundred feet. When I've held on to 3rd, the VQ is absolutely screaming at 6500rpms as I cross the line. As shown by my dyno plot in 4th, my car is only making something like 130fwhp at 6500rpms. If I hit 4th, I'm going thru the lights with about 170fwhp (~5300rpms) and still accelerating.


Dave

matt calder

iTrader: (2)

everytime that i left it in 3rd i got consistently faster times then when i shifted into 4th, of course my rims might play a role somehow.

Rob'sAE

Or you could be a slow shifter.

ejj

iTrader: (5)

I think you misunderstood...

I have to shift into 4th. Otherwise I will hit the limiter in 3rd way before the line.

ejj

iTrader: (5)

Dave -

I've tried this and seen little to no difference. Matter of fact, my best time to date was when I held 3rd to close to the redline.

Dunno...all car's are different. I haven't dynoed, so I can't compare numbers with ya'.

theblue

my times always suck when I shift to 4th. but this does vary with how much gas I have in my car (low gas = need 4th or hit limiter). I respect all your charts and theory but 3th gave me a 14.5 4th only a 14.7

SuDZ

How bad is it to let your car hit up around 6K or so while racing? What I mean is - is there any damage your doing to your car, clutch engine wahtever? Also where do you guy shift at during your regular daily drive? Are you lettign it rev higher or do you keep it somewhat low? Just kind of curious.

SuDZ

AznWontonboy

no one posted this yet, and i dont see why. EJJ and you both get better times in 3rd, and i ASSUME (key word) that shifting takes the time off.. .1, .2, .3, whatever. corrrect me if you guys can shift .2 or faster

Sprint

iTrader: (10)

i dunno.. i shift to 4th at about 6100 rpms in 3rd gear.. and i still have some to go before i get to the marker

E when i asked your shift points.. i was asking what rpms do you shift at for what gears

ejj

iTrader: (5)

Redline for each gear. I've tried lower with different gears, and its never given me better times.

That means that I am into 4th about 100ft before the line.

This is over a course of 50ish runs this summer.

MaDMaX024

how about shift points for VE? typically when racing i shift at 6000rpm. sometimes i wind to redline in first but usually around 6k.

also, i dont know how you guys are winding 3rd to redline. i redline second at 65, isnt 3rd seems to be much taller..i think i've heard its good to 110...(i havent tried, and havent paid attention to the RPM in 3rd at 65mph.).

Sprint

iTrader: (10)

you are actually making less power up at redline.. but if it works for you .. it works for you..

i usually do 6400 rpm in 1st
6200 rpm 2nd gear
6100 rpm 3rd gear

ejj

iTrader: (5)

I know. Don't know why my times are better when I run it all the way up, but they are.

Ants97SE

Yeah, I've been wondering about the same thing, I'm gonna have to check it out when I go out to the track and vary when I shift, if I can ever get a decent launch.

theblue

I've got well over 150 runs this year and I have a couple 14.5s that say my car is better in third and shifted at the redline... get a better time and I'll be thrilled to hear your science... but for now...... 3rd it is...

AznWontonboy

again, i think its becausewhen you shift into 4th, it waste too much time.

Sprint

iTrader: (10)

maybe that WS catback is giving you more top end power.. so you are actually making lots of power to redline?

AznWontonboy

maybe his 16s?

VQdriver

i too have gotten a 14.5 in 3rd gear..i imagine 4th would make the ET slower but trap speed faster. but i guess i'll have to try shifting into 4th @ an indicated 6,100rpm.

Dave B

I come pretty darn close to powershifting on every gear change. A 3-4 shift is a simple flick of the wrist. According to my dyno plot, here are my power numbers from 5000 to 6500 rpms:

4400 162hp/194tq
4600 167/192
4800 171/187
5000 172/181
5200 175/177
5400 174/170
5600 171/160
5800 166/151
6000 158/139
6200 150/127
6400 138/111
6500 130/105

As you can see, there's hardly any power to be found after 6000rpms. It's pretty simple math to see that when you shift, you want to be riding the hp curve. Pretty much you want to be entering each gear at around 4800-4900rpms to ride the power. By over-extending the rpms to redline in 2nd and 3rd, you are entering the power curve too high and you don't get to ride it as long as you could.

You guys are right, it largely depends on the driver's ability to shift quickly. I've had over 30 runs this year with most being shifts into 4th. When I've shifted to 4th, I've hit lots of 14.7s/14.8s@94-95mph. Staying in 3rd always has netted me slower ets and lower mphs.

It's hard to compare our timeslips (theBlue, ejj5875) because you guys live in the northwest and I'm in the midwest. We're so close in et (within .15 seconds) I have no doubt our cars are pretty much equal. My trap speeds are also equal, if not higher than you trap speeds on average.


Dave

ejj

iTrader: (5)

Northeast thank you very much!

Nealoc187

iTrader: (23)

I think alot of it has to do with the person's ability to shift quickly. I attribute my relatively good times to a good launch and the fact that I can shift incredibly quickly. I know that sounds weird, but people that ride with me have even commented on it. Maybe the guys like theblue and ejj that are getting better times without shifting to 4th can't make that 3-4 gear change as quickly, but they are great at the 1-2 and 2-3. Thats the only thing I can think of to explain it, because I'd think all of the maximas with basic bolt ons are making pretty much the same power and have the same shape hp and tq curve. Who knows. Just go with what works for you, and its all good.

ejj

iTrader: (5)

Again, let me clear something up. I always shift to 4th. With my times and trap speeds I have no other choice.

The strange thing about my times is that I get better times if I leave it in 3rd as long as I can, opposed to Dave, who shifts a lot earlier.

maxfreak_98

I would think you have to have similar 60'times to accurately compare the 3-4 shift theory. I will closely examine my timeslips AND shiftpoints during my next track visit. So far my best time and trap speed was done in THIRD gear but it was also my best 60' too (2.23).

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

14.73 @94.1

Sprint

iTrader: (10)

well i do have a short throw shifter

Dave B

So you take 3rd to redline and then shift to 4th. Correct? Doesn't that literally put you within a 100 feet of the finish line? I've tried that too (winding out 1,2,3 then go to 4) and it seems I can do no better than 14.9s that way.

For you guys that leave it in 3rd:

Can't you feel the motor making little power 6100rpms in 3rd? Can't you feel the motor fall flat? My motor makes a lot of noise and sounds like it's going fast after 6000, but in reality it's not pulling much at all. 1st feels fine to redline and 2nd feels decent to 6300 which is a result of the lower gear ratios and good torque multiplication. When I'm shifting 4th, I'm at about 91mph.


Dave

Sprint

iTrader: (10)

i figured it was the catback.. since they both have the same catback

ejj

iTrader: (5)

Exactly...that's what gives me the best times.

ejj

iTrader: (5)

Also keep in mind that I haven't been to the track with my catback or UDP.

So in my case, the catback has nothing to do with it.

MardiGrasMax

iTrader: (14)

Why do you show 14.599 in your sig?
Your time slip chart only shows 14.969 as your best?

ericdwong

Has anybody tried not winding out the gears at all... and shifting at 6K RPM each time?

ejj

iTrader: (5)

My Timeslip link in my sig points to a HTML file that I generated with Excel. Someday when I have "free time" I'll make a normal looking HTML page.

Anyways, across the bottom of the page you should see a bunch of dates. If you click on 08.11.01 you'll see my best times.

MardiGrasMax

iTrader: (14)

Cool! I see it. Nice!