speed limiter?

**Stav** · 29-10-2005, 07:32 AM

Ok so the 3.73 went in last week and I have run in the diff.The main thing on my mind has been the worry of the speed limiter and rev limiter.I have not yet done any speedo or rev correction but ended up on the dyno yesterday.I did reach a speed of 165 kmph .I was supposed to reach 153 kmph ? The other observation that was made was by my tuner where he said to me that the speedo clock had reached 220 kmph at one stage.
I thought the speedo would never reach more than 180 kmph at any time.? I also believed that my new speed limit was 153kmph? Anyone care to comment ?Has anyone seen this before?

Casper · 29-10-2005, 07:47 AM

Well, I'm not sure about the cutout but, unless they were dynoing your car in 4th gear (which is never done for an auto usually) I cant see how its possible to get a reading of 220kph in 3rd.

Given simple mathamatics of the gearing that we know (rpm / auto 3rd gear ratio / diff ratio / tyre size) the maximum you could get to in 3rd gear is about 170kph at 5500rpm. To actually get to 220kph in 3rd with the gearing stated you would need to do over 7100rpm... not likely.

So either they were in 4th (approx 4900rpm) or you have something weird going on with your speedo.

Either way, so long as you are enjoying your new toy.... its all good.

**Stav** · 29-10-2005, 07:50 AM

The 200-220 in third was without any speedo correction ,not true speed .

It is wierd but another forum member has done 200 kays in an au 1 xr6 hp..so he says.

Casper · 29-10-2005, 07:54 AM

Still doesnt make sense. If I'm correct your car "had" 3.23 diff gears in it so thats what the ECU expected to calculate on. If thats the case to get 220kph in 3rd, even with the old gearing, you would be doing around 6200rpm.. WELL past the rev cutout on every AU.

Even with a 3.08 diff its still 5900rpm...

Basically its simply impossible to do 220kph in 3rd gear in any AU auto.

Casper · 29-10-2005, 07:57 AM

Quote:

Originally Posted by useless

It is wierd but another forum member has done 200 kays in an au 1 xr6 hp..so he says.

Nothing weird about it.. the XR6's got the alloy tailshafts and limiters anywhere from 210kph (like mine) to no limiter at all.

This tailshaft was NOT on the utes, lwb luxo's or wagons of any kind, they were all limited to 180kph without exception. Even the TL50's were 180 limited.

**Stav** · 29-10-2005, 08:07 AM

Quote:

Originally Posted by Casper

Still doesnt make sense. If I'm correct your car "had" 3.23 diff gears in it so thats what the ECU expected to calculate on. If thats the case to get 220kph in 3rd, even with the old gearing, you would be doing around 6200rpm.. WELL past the rev cutout on every AU.

Even with a 3.08 diff its still 5900rpm...

Basically its simply impossible to do 220kph in 3rd gear in any AU auto.

I know its impossible ....I think.?? But this was not the corrected speed.it was the exaggerated speed on the clock.

Btw I thought all AU's had an alloy tailshaft? Are these significantly lighter?

Casper · 29-10-2005, 08:21 AM

Quote:

Originally Posted by useless

I know its impossible ....I think.?? But this was not the corrected speed.it was the exaggerated speed on the clock.

It is impossible, corrected or not. As I said, even with 3.08 gears calculating the speed it wiuld still not be possible. Certainly with 3.23 gears (what your ecu thinks it has) its WAY over the rev limiter.

Quote:

Originally Posted by useless

Btw I thought all AU's had an alloy tailshaft? Are these significantly lighter?

No, only the XR6 HP sedan, XR6 VCT sedan, XR8 sedan, TE/TS and Fairmont Ghia sedan got the alloy shaft. They are lighter but, more importantly, better balanced. The will not fit any LWB falcon (ute, wagon, luxo), aftermarket ones are avaliable as a BIG cost, sylox has one on his ute.

**Stav** · 29-10-2005, 09:50 AM

I can probably get one made.

TCK-098 · 29-10-2005, 10:08 AM

Doesnt make sense at all ive had my Fairmont on the dyno a couple of times and it cuts out at 180 "3rd gear" and it still has the standard 3.45.

Dont think any of us would be game enough to run a car in fourth gear unless they wanted the gearbox to let go big time due to the kick down and stress brought upon when on the dyno.

xr8ute · 29-10-2005, 10:18 AM

Casper, my ute has an alloy tailshaft as well....

I don't think it was what the tailshaft was made so much as the overall length of the tailshaft. As you know, the wagon and ute share the same long wheelbase as the Fairlane/LTD luxobarges.....which is the reason why all the LWB had a 180km/h speed limit.

As far as I know, all the LWB BA's have a 2-piece tailshaft to get around the balancing issue with the long single.

jonbays · 29-10-2005, 10:27 AM

Wagons have the same alloy tailshaft as the utes. 180k is the speed limit as shown on your speedo whatever the diff ratio you have.

The same dyno shows 190k on my dyno chart from them when i know the car does not get to 190 on the speedo and on the same dyno the true speed was shown to be 7% less than shown on the speedo.

Now work that out?

How many dyno charts have you seen from speed limited falcons showing power to over 180k? I have seen lots and it just shows how slack the dyno buisness is.

Anyone else got a better explanation?

xr8ute · 29-10-2005, 10:41 AM

Quote:

Originally Posted by jonbays

Anyone else got a better explanation?

I think you've hit the nail on the head ;)

Casper · 29-10-2005, 11:43 AM

Quote:

Originally Posted by xr8ute

Casper, my ute has an alloy tailshaft as well....

I don't think it was what the tailshaft was made so much as the overall length of the tailshaft.

Basically what I meant but yes, probably a better explination.

kryzak260 · 29-10-2005, 12:49 PM

*Runs off to get speedo checked for accuracy*

I have had my AU1 Fairlane at indicated 210 on the nullarbour, so corrected for known speedo inaccuracy, it should have been doing 200 even. Odd, was there any exceptions Casper?

jonbays · 29-10-2005, 03:11 PM

LWB AU's are speed limited we already know that and yes there are some exceptions in the SWB models.

If useles or i ran 210 and the shaft breoke and killed us Ford would be liable as they can be proved to know the limitations of the driveline and the probable consequences. The limiter was cheaper than a two piece tailshaft which was the correct engineering approach to build the driveline to match the cars speed capability.

**Stav** · 29-10-2005, 03:40 PM

Quote:

Originally Posted by kryzak260

*Runs off to get speedo checked for accuracy*

I have had my AU1 Fairlane at indicated 210 on the nullarbour, so corrected for known speedo inaccuracy, it should have been doing 200 even. Odd, was there any exceptions Casper?

What is your month and date of manufacture on compliance plate?Mine is 02/1999

EFFalcon · 29-10-2005, 03:54 PM

the uncorrected speed is what sets the limiter off.
my car hits the limiter at 160ish (3.45 diff with 3.08 sender) which is shown as 180 on the dash.
why its going beyond.. i'm not sure
perhaps the unichips got something to do with it.
i do recall someone saying the unichip *can* remove the speed limiter but not the rev limiter.
don't remember

jonbays · 29-10-2005, 04:06 PM

Quote:

Originally Posted by EFFalcon

the uncorrected speed is what sets the limiter off.
my car hits the limiter at 160ish (3.45 diff with 3.08 sender) which is shown as 180 on the dash.
why its going beyond.. i'm not sure
perhaps the unichips got something to do with it.
i do recall someone saying the unichip *can* remove the speed limiter but not the rev limiter.
don't remember

No both useles and i have unichips mine hits 180 stop on the road for sure but on the dyno the charts i am given show 190 well thats interesting. when i got the unichip tuned asked for a speedo check and it was 7k fast at 100 ie only 93k?

EFFalcon · 29-10-2005, 04:39 PM

i don't doubt that dyno's can be non-accurate in terms of their speeds.
all i'm saying is that the unichip can remove the limiter.

did useless's car actually hit the limiter?

jonbays · 29-10-2005, 04:57 PM

Apparantly not on the dyno at the speed which you would expect it to thats the interesting issue

29-10-2005, 08:29 PM

well just to throw another spanner in the works ,after i fitted our new head and got it tuned .i noticed that they dynoed it in 4th compared to 3rd to the 1st time after gettin the chip fitted.now what is suss to me that my car now makes peak hp at 4900 compared to 5400 before i fitted the ported head .now being a 5spd my speed limiter shuts it down at 4900 in 4th (180 kph on speedo ).looking at the graph they actualy got it to rev to 5100 in 4th ,either my tach is out or the dyno's dodgy .

yobboford · 30-10-2005, 03:54 AM

as a point of intrest, i had a 12/1999 au cab chassis on straight lpg and it had no speed limiter at all, probably because of the lpg side of things but yeah definetly no speed limiter.

and also my steel tail shafted eb wagon also has no limiter, anyway back on topic again, sorry.......lol.

how does it feel with the 3.7's in it????
are you gunna run it down the 1/4 soon????

jonbays · 30-10-2005, 06:47 AM

Quote:

Originally Posted by yobboford

as a point of intrest, i had a 12/1999 au cab chassis on straight lpg and it had no speed limiter at all, probably because of the lpg side of things but yeah definetly no speed limiter.

and also my steel tail shafted eb wagon also has no limiter, anyway back on topic again, sorry.......lol.

how does it feel with the 3.7's in it????
are you gunna run it down the 1/4 soon????

Thats right LPG isn't shut down by the ecu speed limiter only injectors.

**Stav** · 30-10-2005, 08:35 AM

Quote:

Originally Posted by Nik

well just to throw another spanner in the works ,after i fitted our new head and got it tuned .i noticed that they dynoed it in 4th compared to 3rd to the 1st time after gettin the chip fitted.now what is suss to me that my car now makes peak hp at 4900 compared to 5400 before i fitted the ported head .now being a 5spd my speed limiter shuts it down at 4900 in 4th (180 kph on speedo ).looking at the graph they actualy got it to rev to 5100 in 4th ,either my tach is out or the dyno's dodgy .

Go to another dyno Nik. This will help sort out some issues.Believe me dont look at the final figure ,but look at where your peak power is.What rpm ??
If the car is not doing the times then play with the cam timing.Now that the head has been ported , I can bet that it is highly probable that the cam settings may have to be different. My cam timing are set at the "useless" settings. Dialling in a cam has proven to me to be bullcrap.
Rotate the engine and the lifter bleeds down or pumps up and I could never get it right. I reset the cam timing with what made it feel fast backed up by gtech times .If I wanted to I can gain 10-20 rwkws this morning from my engine just by retarding the cam.I will be a dyno day king!!But on the street my car will be a dog!! My car is faster now with 134 rwkws than say 150 rwkws that I can have in 30 minutes time....Anyway..if it idles good I would reset the cam or re do the unichip tune.
EEC IV is a living ecu it picked up the head ..the tune is different.

jonbays · 30-10-2005, 08:52 AM

Quote:

Originally Posted by Nik

well just to throw another spanner in the works ,after i fitted our new head and got it tuned .i noticed that they dynoed it in 4th compared to 3rd to the 1st time after gettin the chip fitted.now what is suss to me that my car now makes peak hp at 4900 compared to 5400 before i fitted the ported head .now being a 5spd my speed limiter shuts it down at 4900 in 4th (180 kph on speedo ).looking at the graph they actualy got it to rev to 5100 in 4th ,either my tach is out or the dyno's dodgy .

This is often the case with dyno operators mate. IF they actually attach the ign pick up to one of the spark plug leads the dyno will give you real rpm vs rear wheel kw and also give you kmh/1000 rpm readings which are accurate.

You are correct though 180k in fourth in a manual is 4900rpm unless you have low profile tyres.

**Stav** · 30-10-2005, 08:56 AM

Quote:

Originally Posted by yobboford

as a point of intrest, i had a 12/1999 au cab chassis on straight lpg and it had no speed limiter at all, probably because of the lpg side of things but yeah definetly no speed limiter.

and also my steel tail shafted eb wagon also has no limiter, anyway back on topic again, sorry.......lol.

how does it feel with the 3.7's in it????
are you gunna run it down the 1/4 soon????

I am doing a once off 1/4 mile on the 5th November. So that will tell how it went... With 134 rwkws it is anyones guess what it will run. Most experienced people say Ill do a 15.7 -15.5..but I beleive in santa claus still so anything can happen.

Casper · 30-10-2005, 08:58 AM

Quote:

Originally Posted by useless

Most experienced people say Ill do a 15.7 -15.5..but I beleive in santa claus still so anything can happen.

That was with the old diff in it. Changing to a 3.73 diff will make a significnat difference. You should be getting close to the 14's by now. Lets face it, dev4 cam, unichip, histall, 3.73LSD... theres not much left to modify, it had better get bloody close to the 14's with all that fruit.

**Stav** · 30-10-2005, 09:07 AM

Do you reckon I wouldnt mind a 14 second pass Casper? HAahah. There is only 1 component which has let me down so far..but even though the results werent great the torque curve grew heaps across the rev range.

yobboford · 30-10-2005, 10:58 AM

im with casper on this one, there is no reason why you shouldnt be breaking into the 14's.

i might head out and run the wagon again on this wed night, try and take a couple more tenths off.

**Stav** · 30-10-2005, 06:09 PM

As I said to run a 14 second I will probably need more power .... Down low the car goes really well so at the end of the day I would still be happy with it even if ran a bad 1/4 mile. I dont believe that 134 rwkws is enough to crack the 14 second barrier.I think if the car does run a good 14 second time then the cam has done its job.If it runs just into the 14.999 then I know the cam is a dud.

Yobboford ...I am a family man and if you want to meet some time pmme...Maybe we can exchange ideas and just talk a bit of bull..Also I may take you for a spin in the wagon?