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-   -   Don't Downshift in Rx7's!!!!!! (https://www.rx7club.com/3rd-generation-specific-1993-2002-16/dont-downshift-rx7s-68623/)

warsaw 04-07-02 11:47 AM

not preserve the synchros, the transmission I mean

jumprdude 04-07-02 01:13 PM


Originally posted by atihun
Downshifting from fifth to fourth does put some strain on the system, especially when you use it to accelerate. Dyno pulls are done at fourth gear, and thats where some poorly tuned engines go bye bye.

Umm, anytime you accelerate strain is being put on the system. Irregardless of which gear you are in.
And dyno pulls are mainly done in 4th gear because 4th gear in FDs is a 1:1 ratio through the transmission, hence it has the most minimal drivetrain loss through the transmission.


Originally posted by ludeowner

If I was cruising along in my FD in 5th and say down shifted into 3rd and the RPM's were to go to 1000 RPM's before redline and just mash the gas, would that cause any strain on the engine?

Read my first sentence.

bluesman! 04-07-02 01:29 PM

Having learned to drive stick on '60's british cars like my '63 MG and '67 TR4a, I downshift almost all the time. I mean, I've got 37k miles and I'm still on my 1st set of brake pads! I've wondered if it wouldn't make more sense to stop downshifting, since my brakes our quite capable and a new set of pads is alot less $ than a new transmission. But I've never had any tranny or engine problem. In my opinon, if you want to drive a true sports car, it's got to be manual, and working those gears (up AND down) is half the fun!

GsrSol 04-07-02 01:51 PM

Don't get me wrong. I know the trannys have a lock out and I never go to first unless I am stopped, I was just proving a point.

I have a friend in an Integra and he downshifts to slow down all the time through all the gears. He goes into first at like 25mph! He has gone through 3 trannys in 2 years.

maxcooper 04-07-02 02:25 PM


Originally posted by GsrSol


I know my 4th doesn't go to 140. Highest I've had it to was 130 and I had to go to 5th, that's with stock size wheels and tires. I would look at the speedo in 1st, 2nd, or 3rd but I don't get the chance, paying attention to other stuff and they go by too quick.

Try it again. 140 is my top speed at the end of the front straight at Willow Springs, and that is redline in 4th gear. I don't think it matters what size wheels and tires you have when comparing the indicated speeds (but of course it matters for how fast you are actually going). You can also calculate it out to convince yourself. Or drive at 4000 RPM and double the speed. The jump to fifth is big, so you want to stay in fourth as long as you can.

-Max

Lost Time 04-07-02 02:27 PM

Uh, nevermind. :)

r_ed_line53 04-07-02 02:35 PM

Re: Don't Downshift in Rx7's!!!!!!
 

Originally posted by rx7superman
Hi......I just read a post from bucrx7. He stated that his engine went bye bye. When reading his post he says that he downshifted to 4th gear to pass up a car. The ? is: Is it bad to downshift on a rotary engine? This is not the first time I've heard of this happening. It happened to a friend of mine about a year ago and to other people on the net aswell. I own all three generations and rarely downshift, I actually put it in nuetral then to gear, but never downshifted from say.....50mph (4th)then to 3rd...I just don't have a good feeling about the way It will sound or what it may do to apex seals. If anyone has any info on this..PLZ let us know:D

You know, this is the most RIDICULOUS thing I've ever heard!!!! These are the kinda people that need to stay off the road or don't get in any car at all. It's hard to beleive that you own 3 generations of rx-7's or any car for that matter and worry about down shifting? Come on!!! You think that all the 7's that are touring or road racing, basically put in neutral and then shift. This get's my blood boiling. If that car can't take the beating then don't buy one or drive one or get in one or ... well you get the picture. It's like getting your motor rebuilt and asking the mechanic if you should baby it because you're afraid that something might happen.
I apologize to anyone who might be offended my comment on this thread, but don't be p**s about your vehicle, especially a "SPORTS CAR" like the RX-7. It's just another sh** we need on our cars, someone saying that our motors will blow up if you downshift. Someone please fix this problem... "I just can't take it anymore!!!!%%&$#!@#@#$!#!$%@#^#%^%"


see ya,

car 53:cool:

redrotorR1 04-07-02 02:50 PM

what ... has no one here ever experienced the 5th to 3rd gear drop? that's one of my all-time favorite "scare-the-shit-out-of-your-friends" tricks ...

seriously, if you race your car in the slightest bit, downshifiting should be second nature to you. and it should not damage the car unless you are operating the vehicle in a lean mode. i love hairpins and chicago boxes in auto-x courses just so i can downshift into 2nd or 1st (during the powerslide ... wheee!!) and rocket out of the exits. i push my FD hard and i treat it right (maintenance-wise); and i have never encountered any engine issues from downshifting. now, i've popped a hose a couple of times but that's an entirely different story. (and for you yutzes, NO, popping a hose is not bad for your engine ... it just means you won't have any boost)

anyone who claims that downshifting is the cause for engine damage or warped rotor (etc, etc, etc) is an idiot. furthermore, such an idiot should not be given the opportunity to mess with a fine marvel of modern technology as the FD3S. ;)

Tim Benton 04-07-02 03:01 PM

redline in 4th gear in my car is the indicated 140 on my speedo too. If your's is showing 130, its messed up.

Tim Benton

neevosh 04-07-02 04:07 PM

The only way I can see people blowing their engines when downshifting is if there's a boost spike when you do it.

Bucrx7 04-07-02 04:40 PM

I downshift and rev match all the time on my rx7. Most likely the reason why my engine blew was due to high mileage. Earlier that day I was driving spiritedly on the way to work and everything was fine. With my luck now and days, it happened when I was coming home from another state.

Tony S.

93TTRX7 04-07-02 04:53 PM


Originally posted by ludeowner
Hi everybody,

I had a question about this whole downshifting thing too. I plan on buying an FD in the future, so I wanted to know this.

If I was cruising along in my FD in 5th and say down shifted into 3rd and the RPM's were to go to 1000 RPM's before redline and just mash the gas, would that cause any strain on the engine?

I drive a 01 VTEC Prelude and when I need to pass someone I usually down-shift to a point where I am right at around 6500-7000 RPM's. Lude has a redline of 7400 and fuel cut is 8000 (I upshift at 7900).

I'm just used to downshifting aggresively, and I was wondering If I do he same thing in the FD, will it cause any unwanted strain on the rotors, housings etc? will the fuel system be able to react fast enough to prevent detonation?

Your car is a bit different. When you downshift a V-Tec you want it DEEP into redline, where you get most of your power. A stock RX-7 should be shifted at 6,800-7,000 RPM because you want to go 3 or 400 RPM higher than your max horsepower point...so in the next gear you will still be in a good power band. Downshifting will not cause harm...just accelerate before you downshift so your motor keeps up to speed.

Ryn, I agree on you on most the subjects here bud...but I don't understand your point on this one. I mean if a car is stock/near stock...wouldn't you want it into 3rd gear where you got a hell of a lot more power? With heavy mods I'd put it into 4th since you would have more torque and horsepower and have a much quicker 4th than a stock car should have.

GsrSol 04-07-02 05:40 PM

The fastest I will take any car is 130 until I can top that in the 1/4 or a long open track. :) I raced a few cars up to 130 and shut it down for 2 reasons.
1) I won't go that fast
2) I won't race in 5th

Seriously, no bs, I have to go to 5th at 130mph. Maybe something is wrong with my car but the other day I passed by one of those portable radar things that the cops put up and my speedo was dead on at 40-45mph.

jspecracer7 04-07-02 08:35 PM


Originally posted by GsrSol
The fastest I will take any car is 130 until I can top that in the 1/4 or a long open track. :) I raced a few cars up to 130 and shut it down for 2 reasons.
1) I won't go that fast
2) I won't race in 5th

Seriously, no bs, I have to go to 5th at 130mph. Maybe something is wrong with my car but the other day I passed by one of those portable radar things that the cops put up and my speedo was dead on at 40-45mph.

Do you have the 4.1 final gear, or the 4.3 final gear out of the RZ?

AND

any one have the top end numbers for the 4.777 final gears?

I found a 4.7 ring and gear set for 20000 Yen, which is $154 or so. I'm about to get a KAAZ diff, so if would be easier just to put the two in at the same time.:D

jeff8932612 04-07-02 09:43 PM

the whole downshifting into 1st sucks!!!!i hate that soo much!! you gotta be going soooo slooooow!

GsrSol 04-07-02 10:02 PM


Originally posted by jspecracer7
Do you have the 4.1 final gear, or the 4.3 final gear out of the RZ?

4.1, previous owner kept the car stock and only took it to one dealership and kept all reciepts.

You can kind of figure out the speed of the 4.7 from this chart.

http://www.rx7.com/cgi-local/3catalog.cgi?cat=2&part=6

Rx7_SD_858 04-08-02 04:08 AM

I should have never read this post becuase today my eyes were pegged on the tach and i was monitoring speed to rpm's. also i was listening for negative sounds coming from my engine while doing this. worse thing is i didnt gain anything by observing all this and i forgot what speed i was in while downshifting at such and such speed. if this happens again tommorow im gonna cut a pink taco out of a playboy mag and glue it where the tach goes. good reminder of what a pu$%* im turning into.

rx7superman 04-08-02 07:41 AM

This is the kind of drama I like to see!!!
 
HI.......I know what I'm driving and I know how to drive.....I simlpy wanted to know what you guys thought of this....I just thought to get some input from my fellow rx7 gurus.....Thanx for all the input...even though some of you guys think I'm f#$%ing NUTS!!:D

P'cola FD 04-08-02 10:24 AM

Hi I drive an automatic and for some reason, when I push the accelerator down really hard the transmission downshifts. Is that bad. :dunce:
Seriously, think about it. If downshifting was bad(for the engine), then the automatics wouldn't do it. BTW I don't really drive an auto.

happyham 04-08-02 01:51 PM


Originally posted by Tim Benton
redline in 4th gear in my car is the indicated 140 on my speedo too. If your's is showing 130, its messed up.

Tim Benton

unless you put on smaller wheels and correctly calibrated the VSS, then top of 4th gear showing up as 130 would be correct.. but then who would be dumb enough to want to downsize their tires? :p:

ruos 04-08-02 06:41 PM

sometimes I find myself listening to my engine and the radio off windows down all the time. Its a way of life with the rotary

highspeed101 04-08-02 07:00 PM

what on gods earth are you guys talking about shifting into 3rd at 90 for? Thats practically when I shift out of third...The car does not do 140 in 4th unless you take in way up into the redline! It actually beeps at even under 130! and shifting into 3rd at 90, you guys are idiots and whoever says thats the way to do it...has actually never done it.

maxcooper 04-08-02 10:20 PM

Yes, the buzzer will go off way before 140 (should be right around 130), but that is because the buzzer goes off before redline (7400 RPM, I believe). 8000 RPM in fourth gear will give you an indicated speed of 140 MPH. I've done it many times. Taking it way up to the redline (which is 8000 RPM, not 7500, though it is admittedly easy to be confused by the markings on the tach) is how you get there.

-Max


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