Sohc Driver

Guyz...im confused...i really thougth that shift points on vtec motors should be at redline...but today at the track..my friend has a 95 GSR..who ran consistent 15.9 shifting at redline....but then we tried experimenting...and he started running 15.5 and 15.4 consistently shifting at 7500. His car is stock too by the way..all he has is a freaking Hayame muffler and a freaking black widow body kit...somethign doesn't add up....so my question is...can anyone help me out with my shifting...what are the ideal shift points for my EX...so far my best time has been a 16.8...with AEM CAI, DC 4-2-1 header, Hayame muffler with custom 2.25 inch piping....i also ran this time on my 17 inch konig monsoons...the temperature outside was in the mid 70s...i want to do better than 16.8..someone help a brother out!...

Khoi

HondaCivicEx98

Well, i dont know about GSR, but my ex with I/h/muffler got best 16.27 and shift at redline(6900). try launching at 5000rpm and set ur tire pressure lower.
mine tire presure was around 22. I did consisten 16.5 when my tire pressure was set at 25 and launching at 4500. So try launching at higher rpm and set lower tires pressure and see if u couc get better times. By the way, the temp was 90+

DragII

yeah, I shift just before redline.

spyder

Redline is the highest point to which Honda recommends you take your engine. It is NOT necessarily the point at which the engine makes its peak power. Frequently engines hit their peak BEFORE redline and they begin to lose power when taken beyond that. If that is the case, you want to shift just a little bit after the point at which it peaks.

DragII

that's true...BUT....in honda engines..peak power is usually only 500 or so RPMs before the redline, so if you do take it all the way, you will be fine. IMO that is

spyder

I agree with what you said about Honda engines, for sure! I was just stating the general theory, not the specific case

DragII

and very well I might add LOL

sirgsr14

ur only problem with shifting after peek power is that the car will usually fall out of vtec not good u want 2 keep it there once its there i have a 2000 civic sir and run 14.9 launching at 4500 and shift in the red at 8300 making the transmission keep the engine in vtec

spyder

Okay, no more crack for you!!!

Yeah, that's all well and good for your SIR (canadian equivalent to our SI). BUT if you will notice, this thread is about the Civic EX (canadian SI). On an EX, VTEC engages at 5500 RPM and the engine redlines at 7000RPM, not the 8000 that your SIR will climb to. Seeing as the EX's VTEC-enhanced powerband is only 1500RPM WIDE, there is no way it will stay in VTEC all the time, even if you take it the 300 over redline it will allow.

Therefore, the best option is to shift right after redline.

Sohc Driver

well..i know shifting in the redline will keep me closer to my powerband..but i just figured something out....i think iwould get better quartermile times if i shifted at 6500...its only a theory guyz..im gonna go test it out...but my theory is that...if i shift into redline....i'll be closer to peak HP of course..but i'll also be breaking traction from 1st to 2nd...my theory now is to shift at 6500 from 1st to 2nd..and shift into redline from 2nd to 3rd to 4th.....if my theory is correct...i won't scratch in 2nd..and..i won't break traction.....im thinking scratching in 2nd hurts me alot...we'll see....i'll post back when i find out...what do u guyz think....

Khoi

spyder

Good thinking along the lines of the breaking traction from 1st to 2nd hurting your times... but try this before you try shifting at 6500. Try going up into the redline, then double-clutch the shift from 1st to 2nd and feather it VERY SLIGHTLY when letting out in 2nd. The double-clutching will a) help the tranny and b) let the RPM drop a little bit more, reducing scratch, and the feathering should get rid of whatever scratch would be left after the double-clutch.

But I think you definately should try out YOUR idea too and see what the results are. I will be interested to hear what you find out! Laters!

Sohc Driver

he he...this is dumb..but please tell me how to double clutch...i never knew how or what that is....

Khoi

spyder

Nope, not a dumb question at all, I didn't know myself until just a few months ago...

In double-clutching, you let the clutch out in neutral between the gears. For example, on the 1st-2nd shift here is the order of what you do:

1. Push clutch in
2. Shift to neutral (keep the shifter between 1st and 2nd, don't let it go back to the center)
3. Let clutch out
4. Push clutch in
5. Shift to 2nd
6. Let clutch out (while applying throttle)

What this does is forces the tranny to match the engine speed BEFORE you put any strain on it, thereby making it last longer (note to others: kinda simplified explanation, I'm not gonna get in to synchros).

I also delays the shift just a little bit, allowing the RPM to drop a little lower. I hope I said it clearly, if anything's confusing just ask!

Sohc Driver

is double clutching bad for the syncros...?

spyder

No, double clutching is actually better for the synchros. What the synchros do is try to match the speed of the transmission to that of the engine so the gears won't grind. They have a harder time adjusting the speed if the difference in speed is large, and they have a tendancy to wear out faster if you are shifting quickly at high RPM. When you double clutch, it forces the tranny to match engine speed WITHOUT using the syncros. This will bring the tranny speed very close to the engine speed, close enough for the synchros to handle without excess wear.

Phantom

you're all missing the target on this one....

when you shift, you want to land as close as possible in the next gear to your TORQUE (not HP). HP is meaningless, torque and where you make it is what counts.

The torque peak on an ex (I'm guessing here) is somewhere in the neighborhood of 5000 rpm. When you shift at redline, you're going to end up somewhere around 4000rpm. You're best bet is going to be to shift right before fuel cutoff, putting you closest to the torque peak.

Phantom

There is absolutely no reason to double clutch when UPshifting, don't look to fast and furious for driving advice.

spyder

You know, Phantom, you really do assume too much. You assume that just because I suggest something that HAPPENED to be said in F&F, that I automatically took it from the movie and that I look there for driving advice. You really should grow up. It didn't even enter your mind that it MIGHT have been from personal experience.

Lets review the basics again. What is the purpose of double clutching??? To match the engine speed to the tranny. This is a good thing whether downshifting OR UPSHIFTING. Now, during an upshift the RPM drops to some extent thanks to the throttle being closed and the tranny will spin down closer to the engine speed for the next gear, BUT it will not be exact. That is something that double clutching can fix.

My synchro going into 3rd gear is TRASHED. If I try to shift from 2nd to 3rd at high RPM, it grinds like crazy and sometimes doesn't even go in. How did I fix this? I started double clutching when going into 3rd. AMAZING, no more grinding because NOW it really is matching the speed!

There most certainly IS a reason for double clutching on the upshift. Before you go shooting your mouth off next time, maybe you should do a little RESEARCH and TESTING first, and not ASSUME so much about people!

Phantom

It seems YOU don't know what double clutching actually does or how a transmission works for that matter, but I'm not going to play professory here. You understand the overall effect of double clutching, good enough.

When I replied, I didn't take into consideration those who destroy their car and continue to try and race them, I am sorry. What I should have said is that there is no reason for double clutching upshifts in a modern car with properly functioning synchros.

spyder

I DO know what double clutching is and how a transmission works, why in the world would you think I DIDN'T???

Once again, you have made assumptions about me, you really should stop doing that, it's not good for your reputation. For your information, I did not destroy my car, the synchro was already damaged by its previous owner. Since I'm going to be swapping out the entire drivetrain very soon, there's no reason why I shouldn't continue to try and race.

Under racing circumstances, there most certainly ARE reasons for double clutching on upshifts:

1) Preserves synchros by reducing the load and wear placed on them
2) Smooths out (and ever so slightly slows down) the gear and clutch re-engagement, reducing wheel spin in the next gear (which was the guy's original problem)
3) Helps keep your synchros from getting screwed if you decide to play stupid and miss a shift. I know EVERYONE in here has missed a shift AT LEAST once.

These are just a few off the top of my head, if I took the time to think a little more I could find others.

My point is quite solidly proven. Where I have provided actual INFORMATION, examples and experiences, you have provided NONE of those and have resorted to trying to insult my intelligence. Why are you doing that? I don't know, I'm not going to make assumptions like you do.

I'm not saying you have to agree with me, there's no way I could force you to even if I wanted to. But I DO ask that you lose the attitude and give the people on this board the respect due to any human. Nothing productive gets done if people just try to bring others down by insults. I agree that if there is incorrect information it should be set straight, but there is NO call for any type of attitude.

Phantom

Why dont I think you know how a transmission works?
"Lets review the basics again. What is the purpose of double clutching??? To match the engine speed to the tranny" (your quote)

No, the purpose of double clutching is to match the layshaft speed to the engine speed, not the other way around. Why (in your mind) do you think the clutch has to be let out for double clutching to work? The answer is the key to what double clutching actually does.

As for racing, you most certainly do not double clutch upshifts. If you're drag racing, you want your clutch engaged for as much of the time as possible - so you definately don't double clutch there. The reason you get less wheel spin is because you're shifting slower than my grandma - definately not helping your 1/4 mi times. If you're road racing and you can heel and toe and double clutch at the same time quickly and smoothly, well you're just one damn good driver, even then, I haven't seen anyone do it. I've rode with some damn good drivers (track instructors, not drag racers), none of whom double clutch.

As for around town, you're not saving your synchros by double clutching upshifts. Your synchros barely do any work when you properly time a 1-2, 2-3 etc. shift.

Double clutching is for old skool trannies and trucks that do not have synchros, for everyone else, there really isn't much need.

Phantom

As for my attitude, I feel it is warranted. This is a good tech board, I don't want it to turn into handa-acura net where 75% of the tech questions are answered by people who don't know what they are talking about. From your advice on shift points to your spiel on double-clutching, you have shown that you don't know what you are talking about.

spyder

Yes, I said to match the engine speed to the tranny, implying that the final result is that they are at the same speed. Perhaps I should have worded it "to make the engine and tranny speeds match" I took it to be a given that it was the tranny that changed to match the engine, seeing as the shaft from the engine has the greater rotational force behind it.

If I am incorrect as to what double clutching is, then pray tell, and instruct me!

Good point about the drag racing. Of course, you also forgot to mention that if you are seriously dragging, you don't give a damn about your synchros or your clutch or anything else. You claim that I get less wheelspin because I am shifting (in your terms) "slower than your grandma". In reality, my shifting when double clutching is only a fraction slower than when I power-shift. My 1/4 times actually improved when I started double clutching (they still suck because an EX is no speed demon, but they did get better). Yes, I can heel and toe and double clutch very quickly, though it is not just terribly smooth yet. I am still practicing at coordinating it.

As for around town, I never said you WERE saving your synchros, I said "IN A RACING SITUATION".

There are some really experienced people on this board who would shoot you without a second thought for saying that double clutching is only for "old skool trannies and trucks that do not have synchros".

speedillusion

from what i've heard... isn't double-clutching bad for the transmission?... correct me if i'm wrong. (that's why i never tried to double-clutch)

one more thing, as stupid as this sounds, my friend told me, that double-clutching only applies when you rev up high(close to redline) and push the clutch in twice(at one time, it sounds crazy, doesn't it?.... lols).

speedillusion

ok. ok. one of you guys need to end this arguemement. the creator has probably left this topic to you guys. now let's get back into some learning. and please put both of your knowledge together and explore our racing world...

payce!