Rev Limit- How high can you go?
 

I have been pondering rev limits for my squirted N/A 1.6. AFAIK, the stock limit is 7,300 rpm.

Im thinking around 7,800 rpm. My car is tracked and autocrossed EXTENSIVELY in CSP with 13" Wheels. This translates into a bunch of time spent on or near the limiter for autox.

7800 will be fine I've heard as high as 8500 stock. But I wouldn't go past 8000.

conversly what's the limits for the BP? stock is 6900 iirc, I've upped to 7200, but am wary to go higher..

Up to 7400 since you autocross and track the car. For street use, where you don't hit the limiter so often, 7600. There is valve float above 7800, so there is absolutely no point going over 7800 on the stock valvetrain. Additionally, the stock pulley damper cannot damp the crankshaft's vibrations at that rpm zone (7600+), so you might have shifting problems (especially 2nd to 3rd) and if you insist on revving that high, you can shutter the oil pump's gears. Above 8000rpm you will destroy your rods. The B6 and the BP are boost friendly, not rev friendly (unfortunately).

How about with boost and carillo rods? i was planning on limiting at 7500 anyway since the turbos gonna start getting less efficent around 6500

7500 sounds fine.

I once overrevved my stock motor (sweaty hands + stock shift knob = :mad: ) to about 9k and nothing blew up... These things are pretty stout :bigtu:

Must have been reminiscing your last time driving a RX7 :)

with a good set of rods, billet oil pump gears, and FM valve springs I'd say 9-10K isn't out of the question... but a lightweight pulley is.

the question is when does the cam stop making power, reving the 8k does not do any good if you stop making power at 7k.

i was under the impression there is valve float above 7800.....

Dont forget solid lifters. Otherwise, you might very well be right, well, 10k might be pushing it a bit far even for that stuff and only ok for short bursts.

You are definitely correct, and something someone should consider before building to a higher redline. On the other hand this thread is about how high you can physically take the rev limit until stuff starts breaking and what those parts are and how they can be modified/replaced to allow a higher rev limit. You could also easily say the same things about porting and turbo selection (assuming you are running one).

The reason for asking is that in autoxing, a few more revs can save a gear change for me. Im not trying to squeeze out a few more HP just make less 2-3 shifts.

Im thinking 7500 for AX and 7300 for track

I've set my redline at 7500 and it pulls hard to the limiter. Prior to MS the power dropped off noticably after 6500.

great fun! :D

It is indeed great fun. I am amazed at how much more peppy my lil' ole 1.6 is now run MS.

I get to try it out for real next weekend at a HPDE in Rockingham.

You pull the MAF yet?

me? ;) yup! :D that made a big difference!

Ohhh yeah! I replaced it with a piece of 3" exhaust pipe until I can make time to put my Fuji Racing IRTB's on.

right on, i think irtb is the shizzle

My '04 MX5 SE (aka Mazdaspeed Miata) now spends a lot of time on the track, I've been killing brakes and tyres, so I'm going to go with the 201rwhp map instead of the 233rwhp one and aim to become a better cornerer. The ECU presently stops the action at 6500rpm, which seemed a good thing with the high power map, but was a bit intrusive in several places on the tracks I drive at. So when I finally work out how to play around with the Haltech, can I go with a higher rev limit with less boost?

Necro thread alert, lol.

You can go a higher rev limit with the same amount of boost = more awesome.

I spin my Mazdaspeed to 7600.


Also: Toasting in a 7 year old thread!!!

Jeez! I obviously hadn't noticed. Sorry 'bout that and thanks for the answer. I'll wind it up to 7250.

7600rpm is outside of my comfort zone for a factory motor. The rods aren't going to like that for long. 7250 is a much safer number.

Again, sorry for the necro. But reading more about these motors makes me feel happier leaving mine at 6750 bearing in mind it hits 16psi at those revs - because apparently revs kill rods?

torque/pressure kills rods.

So what rpm can I safely go to?

What is done to your motor? The stock redline of 7200 should be more then safe.

Stock redline is 7000. 7200 is safe forever (i.e. endurance cars). 7400 for HPDE/normal track cars. 7600 for street cars that might see that figure once a day for a moment.

Run an HPDE car at 7600 and it will blow up eventually. Run an endurance car at 7600 and it will blow up fast.

What breaks? Eventually I'd like to get a Supermiata crank gear and wheel, Skunk t-body, and then rev higher...but that's a lot of scratch.

idk about you fags but I rev my car to 12k all day every day because the sounds of det make my cock swell

I think it depends on which head you have and what is done to the head.

The head on my turbo car has supertech springs so that's nice.

Different stuff breaks depending on the application. Enduro/track cars will typically break the throttle shaft first, then break the crank pulley bolts, then damage the valvetrain (7500+), then stretch the stock rods (7600+). If you expect OEM reliability at 7500+, you need to address all of that.

Breathing, fueling and a piggy back ECU. No changes to the internals, which I guess is why the previous owner left the redline at 6500 as set at the factory. It's at 16psi at 6500. The 173.4kW = 232hp.

I will continue rolling with a spare throttle-body in the track trailer...one day that Skunk TB will join me in holy mantrimony.

Lets not pretend all motors are equal. So here is what i have on my 1.6L.

Started off completely stock driven by grandma until 46K miles. Then i got it. drove it on the track for a little over 1K miles then. Full exhaust, Intake, Megasquirt 126WHP. Raised the RMP to 7,500 and have been driving it for the past Year and 1/2 for at least 2 track weekends a month. I bounce of the rev limiter almost religiously and beet the hell out of it. I change the oil very 2-3 events stock oil filter and Rotella T6. I have a coolant reroute 180 thermostat and ducting for rad. I never see temps over 185 on the track even when it is 100 gotta love Texas. I have no idea what my oil temps are and that has been on my mind so i'm installing a sensor as soon as i stop being lazy. I run 225 Nt01's 87oct and im waiting for the motor to fail so i can try a hot 1.8.

Wonder if he'll log in for the first time in 4 years to see your reply. :giggle: :bowrofl:

lol how the hell did i bring this thread back form the dead? :noob:

Not that I am into necro or anything but this thread is on point. I have done some reading on bumping up the rev limit and this helped me out.

I autocross very competitively quite often (20-30 events/year) and attend 1-3 HPDE's/year. I am looking to increase my rev limit because when I autocross I am too often at the limiter and I end up losing ground/time. Switching to 3rd and then rev matching down is fun but that also loses me time. I am planning on bumping up my limit to 7,500 this season (lower for track days). I think I should be safe. What do you guys think?

Here are my specs:
95 bottom w/ 99 factory head. ~5k miles since it was built.
MS2
210 - 240 whp
Forged rods and ARP hardware all around
FM lightened flywheel
4.1 diff (switching to a 3.9 this season)
225/50-15 tires

According to the FM gearing calculator, with the new rev limit and the 3.9 diff, I can take 2nd to 72 mph!! I can smell a few more FTD's this season.

Thanks in advance.