XR8 Rev limiter

[fordman302]

Hi all, just a quick question for anyone in the know, i was wondering if an au xr8 would have a rev limiter and if so where it is set at, i always thought i was hard on the car but i have never managed to hit the limiter if it is there.

I have searched and googled this and just cant seem to find an answer, thanks in advance

[dieseltrain79]

Find quiet road , select 1 , floor it , watch tachometer ! Win ... Hehe

[fordman302]

Originally Posted by dieseltrain79

Find quiet road , select 1 , floor it , watch tachometer ! Win ... Hehe

i will take note of when it throws a rod and mark that down as the limiter

[BHDOGS]

Isnt it 6000 on them?

[Ford Falcon XR6]

Think its 5850 but i may be wrong

[LXV139]

I thought they were up round 6300 or close to that. My brother in law has a stock 2002 model and it revs over 6k

[CRAIGAU3220]

Don't know about all model variations but the 220 is set at 6250rpm..............Hit it plenty and still have crank and rods in side the sump..........For now at least

Must say I don't intentionally try to rev it to limit...........If air is crisp and dense it is worth reving to 6000rpm at the drags..........Warmer weather and or humid conditions a little over 5500rpm is about it, past that I can feel the power drop away.

[b2tf]

on a reasonably stock motor anything over 4k is just noise.

[madmelon]

Originally Posted by b2tf

on a reasonably stock motor anything over 4k is just noise.

How do you figure? Peak power is 5000-5250rpm on the AU series 5.0L engines.

I have one of the last AUIII XR8's made (August 2002) and I set out to determine where the limiter was on the highway. Put it into second, booted it up a massively steep hill and it stopped dead on 6000rpm, got there slower than it usually would 'cause of the hill, so needle lag wasn't a factor.

From what I've seen, this 6250-6300rpm limiter business is something of a myth. In saying, I haven't seen all that much...

[CRAIGAU3220]

Originally Posted by madmelon

From what I've seen, this 6250-6300rpm limiter business is something of a myth. In saying, I haven't seen all that much...

You could be onto something there...............I had been told a few times its 6250rpm, and as I said before I haven't gone for rev cut out on purpose so had always been a little puzzled when trying to shift a micky hair before 6000rpm and hit fuel cut............Was thinking the tuner had lowered limit to 6000rpm but maybe that's were its always been at??

[auIILTD]

Originally Posted by CRAIGAU3220

You could be onto something there...............I had been told a few times its 6250rpm, and as I said before I haven't gone for rev cut out on purpose so had always been a little puzzled when trying to shift a micky hair before 6000rpm and hit fuel cut............Was thinking the tuner had lowered limit to 6000rpm but maybe that's were its always been at??

Craig, from what I have seen in tunes, I think Ford kept all the rev limiters at 6000rpm. I have been privy to the 185kw, S3 ute 200kw tune and of course my T3 250kw tune. All of them are limited at 6k. My guess, based on knowing how conservative Ford where/are with their tunes to protect themselves, is that the 220kw was/is much the same.

One of my tests to perform is see the fuel come back in at 5900rpm. Most of use when we hit the limiter either change gear or get out of the throttle. I have not seen the rev limiter perform as the tune dictates.

Cheers
Stu

[b2tf]

Originally Posted by madmelon

How do you figure? Peak power is 5000-5250rpm on the AU series 5.0L engines.

I have one of the last AUIII XR8's made (August 2002) and I set out to determine where the limiter was on the highway. Put it into second, booted it up a massively steep hill and it stopped dead on 6000rpm, got there slower than it usually would 'cause of the hill, so needle lag wasn't a factor.

From what I've seen, this 6250-6300rpm limiter business is something of a myth. In saying, I haven't seen all that much...

'Peak Power' is exactly that - where it hits its limit. The usable power band is between about 1800-4000rpm and that's where you would spend most of your time under normal driving conditions anyway. I'm yet to find someone who redlines it every gear change, and if you do you're wasting your time and fuel.

[auIILTD]

Originally Posted by b2tf

'Peak Power' is exactly that - where it hits its limit.

100% correct.

To my understanding, peak power figures have nothing to do with usable power range. Peak power is a statistic. Usable power range is an opinion (at minimum is subjective).

Stu

[madmelon]

Originally Posted by b2tf

'Peak Power' is exactly that - where it hits its limit. The usable power band is between about 1800-4000rpm and that's where you would spend most of your time under normal driving conditions anyway. I'm yet to find someone who redlines it every gear change, and if you do you're wasting your time and fuel.

We're here talking about rev limiters and you're here talking about mid range, every day driving, usable power?

Originally Posted by xr8ute

I was reasonably sure the 220's were higher than the rest, but I dont have BinaryEditor on my work laptop to check.

Be carefuly how you measure RPM though. The factory tacho's (and speedos) are not very accurate, and it would be useless to use it to determine where the rev limit is set IMO

My factory dash tacho would always read a few hundred RPM higher than my datalogs which where taken from the clean tacho output (CTO) pin on the EEC plug. Which one do you believe?

I can repeat the exercise with the dash in diagnostics mode if you wish but since they correlate well on my car and there are tuners saying it's at 6000, I think it's pointless.

I have read a magazine artice from when the AUIII XR8 was released and it referred to a "banshee like wail at the 6250rpm cutout". That is the only time I've ever come across it "seen" as 6250 (it was shortly after this I did the test). We know how press cars can be "tweaked" and tachos can be inaccurate...

[b2tf]

Originally Posted by madmelon

We're here talking about rev limiters and you're here talking about mid range, every day driving, usable power?

Yes and if you read my post again you will see the point I am trying to make is that on a reasonably stock engine the usable power is achieved well BEFORE the rev limit.

[dieseltrain79]

If an engine throws a rod for hittIng the limiter , it wasn't I. Good nick to start with ;) that's why it's there , so it won't leg a rod !

[fordman302]

Thats good to know thanks fella's, i have an engine that is a fair bit removed from stock and in any loss of traction shoots straight up into the red within the blink of an eye, just wanted to make sure there was omething there that can look after it

[auIILTD]

On both my stock 185kw tune and my T3 tune, fuel is cut at 6000 rpm and is not re-instated until RPM reduces to 5900rpm. I have not changed this in my T3 tune from the stock value.

Stu

[xr8ute]

I was reasonably sure the 220's were higher than the rest, but I dont have BinaryEditor on my work laptop to check.

Be carefuly how you measure RPM though. The factory tacho's (and speedos) are not very accurate, and it would be useless to use it to determine where the rev limit is set IMO

My factory dash tacho would always read a few hundred RPM higher than my datalogs which where taken from the clean tacho output (CTO) pin on the EEC plug. Which one do you believe?

[Sox]

Originally Posted by xr8ute

I was reasonably sure the 220's were higher than the rest, but I dont have BinaryEditor on my work laptop to check.

Be carefuly how you measure RPM though. The factory tacho's (and speedos) are not very accurate, and it would be useless to use it to determine where the rev limit is set IMO

My factory dash tacho would always read a few hundred RPM higher than my datalogs which where taken from the clean tacho output (CTO) pin on the EEC plug. Which one do you believe?

Bang on.

My understanding was that it was 6250 on the 220 donk.
However, I just went for a drive into the big smoke, and on the way home I hit the limiter in 1st a couple of times to eyeball it, and the tacho read a frag over 6000, probably 6100.

My guess is that the limiter is at 6000.

[james22]

My 220 seems to be around 6200rpm, so 6250 is probably correct. Usually shift about 5500rpm though.

[crakrz]

XR8ute, you are correct. My stock Au3 XR8 220 bin. file says limiter 'on' at 6300, turns 'off' at 6200.

[Mr Hardware]

all i do is put it in neutral and rev like bam-bam-bam-bam-bam and select D for maximum respect. It just bushfires the shithouse every time

[madmelon]

I wonder if the cast iron headed engines have a different setup to the alloy headed engines.

crakrz, which is yours? Mine is cast iron.

[crakrz]

Cast Iron

[5.0 ED]

They very between which factory tune you have, as crackz has said his is 6300on 6200off, i have seen other AUIII 220kw's at 6000on 5900off.

Seems to be they are normally set a little higher on Auto's then manuals...

Early 220kw T series at 6100on 6000off, early S1 XR8 at 5700on 5600off.

So whatever it is, is just whatever calibration you got.

[fordman302]

So after a little "investigation" i found my rev limiter is at 6000 and just sits there nicely, no harsh cut out or anything like that