Bunta Fujiwara

Don't know about that yet (am finding out) but when it comes to Wankel rotary engines, such as the Mazda 12A and 13B, redlining it is really conceptually impossible as there is no redline. The 1982 RX-7 that I am planning to buy, with a carbureted 12A twin rotor, is capable of over 14,000 rpm for very brief periods. The only real limit per se with a rotary is the sparking interval. Once the rotors are spinning faster than the spark plugs can spark for combustion, the engine will not run any faster. For example, the NSU KKM, or Kreiskolbenmotor, can rev up to 12-15,000 rpm for short periods. This is a standard rotary production design. The DKM, or Drehkolbenmotor can reach up to 36,000 rpm safely, but was never made for production as it has to be completely disassembled to change the spark plugs and perform any other maintenance. Obviously this type of driving behavior would almost immediately destroy any rotary engine, but it is possible to rev them that high. Sorry that is all a little off topic, but I thought it would be good to clear it up.

ovrrdrive

If you notice in his sig he has a 2wd truck.

The shift points are completely different due to the gearing.

Bunta Fujiwara

Ah yes... that's right, it is a 2WD truck. The gearing would be different. However, as it is the same engine, my understanding is that the rev limiter would still apply at the same rpm, just at a different speed, say 30 mph vs. 36. Although when at 32 mph as I mentioned, I never bounced off of any limiter. Had I kept my foot down, that engine would have kept spinning up. So I'm just curious as to where those points are. I'll post my gear ratios later today to compare with 2WD ratios. Of course the final drive would also have to be factored in, and that may well be where the real difference is.

91_4x4runner

I think that the 2wd trucks had either 3.7 or 3.9 diff. gears whereas most of the 4WD trucks had either 4.11 or 4.56.

ShoeRunner

There is a rev limiter? If it is above 4200rpm I may never find it! I bought this motor with 216kmi on it and it is currently at 223. It seems like she really doesn't pull much any more past that, but then again I have never tried. I like the torque at 3k that I get when I shift at 4k. I did the seafoam thing last year, but I think I was a little to gingerly with it and need to try it again. You guys are saying every oil change, I didn't realize it should be that often, but it sounds good to me.

You guys aren't kiddin' about the 3.0's being slow. The only time I raced this truck was against my friends '94(I think) 4Runner 5spd and it was a dead heat.

longhungsilver

I still havent used seafoam.. do u run it through the engine for 10mins or so before u drain the oil?? or is it sumthing u run with the oil for the length of your oil life??

dijlop

i havent seafoamed anything either. of course my engines only got about 75k on it. yea boi. but yes, my truck is 2wd, and im sure the gearing and such is different. i have an idea for you. if u want to find ur redline, find an open strip and floor it in first till the engine cuts. then shift to 2nd, and floor it till the engine cuts. those first two are probally all u will ever need. lol. by then ur either ahead or toasted. and once u know when the engine cuts out, u'll know what u can max without dropping speed due to engine cut. problem solved forever.

Superflex84

I agree with most of the 3.0 owners... mine doesn't make power after 4k so what's the point? floating valves sound like crap, so I don't bother.

I also own vws... I had a 90 jetta coupe with a vr6 swap, and that thing loved rev limiter! 250k miles on a stocker... no noises

I think it greatly depends on the brand, and previous owners habits

Jay351

My truck pulls pretty well up to around 5,000rpm, Im asuming it was the exhaust system that opened up the top end

curly_c

i once would never shift passed 3200 to "save gas" but seeing as i get 12mpg and it never changes, i rev the hell out of it now. dont shift under 4k much anymore. and my MPGs dont change. try to get as much power out of the 3.slow as i can.

Bunta Fujiwara

My gears are:

3.954:1
2.141:1
1.384:1
1.000:1
0.850:1

with a 4.110:1 rear end. dijlop's is probably a 3.6. Same gearbox ratios, though.

dijlop: your idea sounds good, as long as I won't blow my engine. I'll only do it once, though. I'm staying a few hundred below redline for the rest of the engine's life unless it's an emergency (hopefully to 1 million plus). I normally shift at 3000-3500 during normal everyday driving, and then I'll wind it up to 4500-5000 in the canyon. Driving in Colorado can be very fun and also very interesting, especially with a carbed engine. I remember when my dad took me over trail ridge road when I was a kid in the old '85 solid axle 22R truck. That baby wasn't going over 35 mph, no matter what. We still kept up with the flatlanders, though.

Took the '93 up to 55 in 2nd today. It still hadn't hit any limiter.

Bunta Fujiwara

According to Paul Cherubini, there is no limiter. But he doesn't know everything.
He knows alot, but not everything.

SwampThing

Another good thread on rev limits, redlines, and rpms...

https://www.yotatech.com/forums/show...ht=rev+limiter

Bunta Fujiwara

Thanks for the link. One individual in there mentions redline as 5750, though it is actually "6200". 5200/5750 is for a 20R. And although 6200 is stated by Toyota as the attainable maximum, it revs much higher than that before the limiter. I would say that it could even handle up to 8000 for very brief periods (such as hit and upshift) and not break. Doing this on a regular basis would obviously destroy it. I'm guessing that the real redline is somewhere from 7500-8000.

Not to encourage revving it like that... I certainly never would.

Shoua

4 to 5 times in 15,000 miles? And you are worried? Don't worry about it. Engineers put their redlines at safe rpm's on their engines. That's the way they designed them. Engines are tested for long periods of time, through every situation it could encounter, before being finalized and put into vehicles. So you're fine, as long as you don't redline it in every gear every time!

Robrt32

I baby mine always shift around 2000-2500 and never drive it over 60 MPH , 260 grand on it and still purrs like a kitten, no oil leaks and no smoke... It works for me and plus i'm never in a big hurry.. I just leave in plenty time

deserttoy84

only time I really pushed my motor i got up to 4800. wont ever go that high again, No point. The water trick acutaly works awsome. If youve never used a steam cleaner them you wont get how it does work. if your against it seafoam it to "blow the crap out" that crap is still gonna stick even if you rev it to the moon. Just like the dust on your paint job wont come off if you do 100mph, it needs to be washed to come off.

Bunta Fujiwara

I professionally clean carpets for a living, so I know what you're talking about there. Still wouldn't run it in my engine, though.

Bunta Fujiwara

I've heard of people maintaining 5000 on the 22R/22R-E up steep grades for 10-15 mins. straight. Do you think that is really safe to do?

MudHippy

My 3vze makes all it's power after 3000 rpms. All the way through about 6000. I run it hard, keeping the rpms between 4500-6000 for periods that last several (10-20) minutes, weekly on average. At times I need significant, constant, wheelspin while wheeling is my reason for doing so. That and I've learned not to be afraid of it. I've ran the hell out of it, never wants to even get close to hot or get tired in any other way. Hell of a tough engine, maybe I got THE good one.

Water/steam treatment has been around since my grandfathers age. Not likely to hurt much if done correctly. Practiced by many aircraft mechanics. My grandfathers profession.