Re: Poll: Who has ever hit the rev limiter?
 

I've ran right through 7000 RPM, and the car was still pulling strong with no drop off, then right through 8000 RPM accidentally, and I've bumped the rev limiter a couple of times when I wasn't paying strict attention....best I can tell, it is set at 8200 RPM on my car. After that, I called Lingenfelter, and they thought is would be fine to 7800 RPM normally.

:jawdrop::jawdrop:

Re: Poll: Who has ever hit the rev limiter?
 

I thought the chains became the limiting factor over 8000rpm as they will break due to the small diameter of the sprockets, which were designed small to fit the LT5 into the C4.(in the end the cam sprockets could have been a tad larger it was found)

The secondary chain lets go, and then due to the LT5 being an interference engine, valves start smacking pistons and carnage ensues.

Hitting the rev limiter induces no ill effects. The engine simply defuels allowing revs to decrease slightly, then refueling once again. Floating the valves (where the lifter actually loses contact with the camshaft lobe) would be difficult with stock parts that are working correctly.

Re: Poll: Who has ever hit the rev limiter?
 

SO what im looking at is... theres 55 people so far who don't even know how fast their z is yet ? =D>

Re: Poll: Who has ever hit the rev limiter?
 

In my opinion hitting the rev limiter is ok but of course repeatedly doing that does in my opinion stress the chain as the sprockets are slowing and accelerating the chain back and forth. Also not all engines have a rev limiter because the engine will not spin that high and explode. More so due to the fact that they are cammed for lower rpm and efficiency and mileage so the powerband is pretty much over so they just set the limiter where it needs to be. There are a lot of motors that can safely rev a LOT higher than a factory limiter like some of the jap cars (2jz etc) with no ill effects. They just crank the boost and up the rpm on a stock motor and away they go.

Re: Poll: Who has ever hit the rev limiter?
 

And just for the record I hit it twice because I needed to know where it was after all the mods lol. :-D

Re: Poll: Who has ever hit the rev limiter?
 

The question of tach calibration...comes to mind. (Mine would read "off the map" at the limiter due to calibrations error.)

Re: Poll: Who has ever hit the rev limiter?
 

I agree with all in that hitting the rev limiter once or twice is not a big deal, but I think bouncing off the limiter as I see of the 4 cylinders do on launch make me cringe. Good think we have our friend Torque so we don't have do that.

Re: Poll: Who has ever hit the rev limiter?
 

Are you sure you're driving the right car? :D

I have redlined mine many times and plan on hitting it a few times today - autocross this afternoon! Sure these engines make torque, but they live for revs. I agree a redline launch is totally unnecessary and probably not ideal, but get it on a road course and really work that last thousand rpm. It's awesome.

Re: Poll: Who has ever hit the rev limiter?
 

Yes Im driving the right car thanks very much.

Re: Poll: Who has ever hit the rev limiter?
 

When I owned Barney, I hit the rev limiter once in a while, mostly in first or second because I didn't properly anticipate the delay in the tach. What I wouldn't have given for an HUD back then.



As I ran my car on the chassis dyno enough to know where the engine made power and what the best shift points were, I almost never would tag the limiter intentionally. The Street Skinner engine in Barney which used stock manifolds and cats made right at 500-hp but it peaked at 6500 or so and was "all done" by 6800 and that's where I usually shifted such that after the shift I ended up down around peak torque.


With my current ZR1, Bad-Assed Bee, I'm always hitting the limiter in first and second if I'm manually shifting. Left in drive, the darn thing always shifts just before the limiter.



Innovation and Technology rears its ugly head.

Re: Poll: Who has ever hit the rev limiter?
 

I treasure my car.
I baby the car.
I LOVE my ZR-1!

That said; If you are not, on occasion,bumping into the rev-limiter, then either let someone else drive it if you really cannot bring yourself to do it and witness that the sky will not fall.
OR
Play a little more aggressively with it each time until you do.

Few things in life are as much FUN as DRIVING a C-4 ZR-1.
Any car revs to 5,000.
6,000 still quite a few.
7,000 not many

Aim for 7,500 by holding off until you see the needle pass through 7,000.
At the rate age is slowing me down, I may have to soon start the shift at 6,000 to hit 7,500
When young, I left on the last yellow light.
Today I could almost start one second after the stage light glows.
Ahhhh, the golden years!!!!!!!!!!!!!!!!!

ENJOY IT WHILE YOU CAN!
Go for 7,500!!!
:cheers:
Marty

Re: Poll: Who has ever hit the rev limiter?
 

ZR-1 tachometers are notoriously inaccurate due to the IC within the instrument panel cracking and changing resistance due to age, heat and vibration. Batee.com sell a 90-96 Tach Fix 8000rpm kit for remedying this problem. In order to verify the accuracy of the tach, plug in a Tech 1 or ALDLDroid or similar.

Re: Poll: Who has ever hit the rev limiter?
 

I just hit the Rev Limiter for the first time yesterday. I hit it on a car that had the Tach corrected recently after being told it was reading high. I had the same reading corrected on another car. My guess would be that most Tachs read high. I see 7000-7500 occasionally and have only hit the limiter (once). Hitting the limiter for the first time took all the fun out of it, immediately! If the factory rev limiter is set at 7070 RPMS +/- and I can bump 7500 on a stock 90 without hitting the limiter then I must be reading high on that car also. Just my observations on the matter.

Re: Poll: Who has ever hit the rev limiter?
 

After I finished calibrating the tach and doing my "510" porting (& Marc Haibeck tuning), I'd hit the rev limiter in 3rd gear about 100 yards BEFORE crossing the 1/4 mile trap. Marc Haibeck had to bump my limiter to 7500 to solve the "problem". I don't hit the rev limiter very often now tho. (I'm good for 121 mph in the traps now, in 3rd gear.

You can see from the 3.45 gear chart where the (7100 rpm) rev limiter would be a hindrance when trap speed of 121 in 3rd gear was in play... Oh! And if you haven't tried the "510" package, you don't know what your missing!!!

Edit: Update: Nearly 1/3 of Z owners have never "let the BEAST out of the cave"! Shame on you! [-X

Re: Poll: Who has ever hit the rev limiter?
 

Hit the limiter on the back straight at the Corvette Museum Motorsports Track. Then I had to slam on the binders to turn. It was glorious!

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Re: Poll: Who has ever hit the rev limiter?
 

If you've never hit the rev limiter, you're not driving it hard enough! :wink:
Having said that, once I put a Raptor shift light in mine, I never hit the rev limiter anymore and I run my car to the shift light every time I drive it. My rev limiter is 7400, and my shift light is set at 7300. The shift light is in the AC vent pointed right at my eye and as soon as it lights, it's an instant reaction to shift (don't actively think about it, it's muscle memory and subconscious reaction). I've spend a LOT of money on this car, and the shift light was the best mod I did to it.

Re: Poll: Who has ever hit the rev limiter?
 

Why, the power drops off before you hit the limiter.

Re: Poll: Who has ever hit the rev limiter?
 

What is the rev limit on a Z? Honestly, I've never noticed on a hard run. I know I've hit it because the engine is saying that's all I got, time to shift.....But never been looking at the tach at time of shift to see exactly.

Re: Poll: Who has ever hit the rev limiter?
 

Guess I should have clarified, I'm running a 391 with stage 2 cams. The power does NOT drop off. :)

Re: Poll: Who has ever hit the rev limiter?
 

Cool is it a stroked engine?

Re: Poll: Who has ever hit the rev limiter?
 

Haven't hit it nor do I know what it is set at.

Only purchased the car a few weeks ago. 368ci Corey Henderson built 1991 Z. 4.10 gears. I did 3 pulls in second gear and the tach needle swept just above 8000 each time at which point I decided I better shift. Don't know if it is accurate but sure sounds like it's well north of 7000 anyway.

Re: Poll: Who has ever hit the rev limiter?
 

Technically not stroked. It's one of Pete's 391 cubic inch closed deck blocks (larger bores) with stock crank. Add to that Pete's port work of everything and his aggressive stage 2 cams (plus of course long tubes, no cats and Corsa exhaust). Makes peak power at 6500rpm and holds it all the way to redline. Build thread here.

Re: Poll: Who has ever hit the rev limiter?
 

You need to get your gauge cluster redone by Batee. When I bought mine, it was the same way. I could bury the tach past 8K and never hit the rev limiter. I used gps speed (Google Maps or Waze) on my phone to compare to tach one day and calculated it was at least 2K off. Having the shift light makes it even easier though as I can keep my eyes on the road and not have to watch the tach.

Re: Poll: Who has ever hit the rev limiter?
 

Thanks for the tip. Will verify rpm vs speed first. Also,planning to install a shift light.

Was your tach off a consistent percentage throughout the range or was it only skewed at the top?

Re: Poll: Who has ever hit the rev limiter?
 

It's been several years, but I think it was skewed more at the top end (pretty sure I would have remembered it being off by 1K or more at idle).

Re: Poll: Who has ever hit the rev limiter?
 

Welcome to the BROTHERHOOD OF THE BEAST!

Here is a chart you might use to see if your tach is tracking correctly...assuming your speedo is corrected for the 410 gear!

And...(IIRC) there is a way to determine the RPM from the DIC (digital information center - the display in the dash). As I seem to recall, (someone please chime in here!) a number can be retrieved and a multiplier is used to ascertain the actual RPM. OR, if you have a scanner, of course you can read and compare the analog tach to the digital reading.

P.

Re: Poll: Who has ever hit the rev limiter?
 

I checked the tach gauge vs the readout on the HVAC control. Hold up and down fan speed buttons simultaneously until 00 appears then tap up until 06. Tap the fan button. This gives you rpm/25. It won't read all the way to 7000 but I was able to verify my tach gauge reads about 15% high throughout the entire range. So 8000 is really only about 7000. Will have to get it calibrated.

Re: Poll: Who has ever hit the rev limiter?
 

I don't feel like reading the whole thread, but I'm wondering... I feel like I drive the car really hard... But I don't recall hitting the rev limiter! What happens when you hit it, RPM decreases a little bit by itself, then increases back up?

My 1993 had a steady rev limiter, RPM doesn't decrease when I hit it...

Re: Poll: Who has ever hit the rev limiter?
 

BATEE can either do the work for you, OR they can sell you the resistor circuit board replacing the old one, OR you can build you own precision voltage divider and install it yourself. (Personally, I built my own voltage divider, but that was before BATEE was known to me, and the fact they now sell the "chip" for DIY'ers like me!)

Re: Poll: Who has ever hit the rev limiter?
 

The power doesnt drop off in a stock LT5 before redline.
Unless you go past the power peak, you will be way below it after your shift.


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Re: Poll: Who has ever hit the rev limiter?
 

Well, in a stock motor, one starving for air, BTW, POWER does dip before the 7100 red line. In fact sources including "Mr. Jingles" (one of the (former?) test drivers for GM said he power shifts the ZR-1s @ 6200.

But, your right after the shift puts you right on top of the torque curve and behind the power peak as it is ramping up again.

Porting the LT5 - even (as I am) running stock cams, really turns the BEAST loose, and then the LT5 is just on the crest of the power curve (on a 5.7L motor). Add regrinding of the cams and some judicious phasing and you'll need to reset the cutoff to 7500 or 7600 or more to appreciate what the motor will deliver.

But, you don't have to take my word for it...ask Pete Polatsidis who ran his 5.7L LT5 to the low 11s on a regular basis before dropping in Kevin Costelos' 441 LT5 (that Pete also built).

Pictured are some more or less typical (inertia) dyno graphs showing the before (stock) and after (ported) results. Note the stock engine was cut off at ~ 6300 rpm, but the HP is just seen to be ebbing even then. And, the ported LT5 (before and after) shows the HP is at its crest at the 7000 rpm mark after porting; a significant improvement!

Re: Poll: Who has ever hit the rev limiter?
 

After my 415 build, I found the limiter pretty quickly. Mark did not change the upper limit.
This thing revs so fast, I wasn't ready.

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Re: Poll: Who has ever hit the rev limiter?
 

Can't say I ever have, try to shift before 6K or so when I'm trying to blow the carbon out. Near stock power is just fine for my driving profile & level of driving skill.