Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Smallfry]

Can anyone out there tell me what RPM are when running at 70 mph in 5th in a manual gearbox 2.5 V6..............1998 or earlier please.

Also, do any of the manual gearbox omegas have a speedo cable.........or are they all electronic ?

I don't have a complete Omega..............only the engine and box in another car.................well nearly !

[Kevin Wood]

All Omegas have an electronic speedo. The signal to drive this comes from the ABS / Traction control ECU and is derived from the signals from the ABS wheel sensors.

Not sure about the gear ratios I'm afraid.

Kevin

[shyboy]

I think my 2.6l 2001 estate runs at 3.1k rpm at 80mph and 3.6k at 90mph., both in 5th, so 70mph would be under 3k. Don't know by how much exactly, but I will post again when I next read it.

[Jay w]

mines a 2.5 auto, but

70 - 2900/3000
80 - 3300/3400

[Smallfry]

All Omegas have an electronic speedo. The signal to drive this comes from the ABS / Traction control ECU and is derived from the signals from the ABS wheel sensors.

Not sure about the gear ratios I'm afraid.

Kevin

Thanks for the replies guys ! That helps a lot in my calculations..............

But by what Kevin says, would I be right in saying that there is no sensor or take off in the gearbox itself relating to speed ?

If thats so, its going to be difficult to overcome  

[Kevin Wood]

Let us know what sort of project you're planning and we may be able to help.

I don't know the manual gearbox myself, but it may have a provision for a speedo cable or sensor that's simply blanked off in the Omega and can be reinstated.

Failing that, I have a speedo sensor in my kit car that is essentially a variable reluctance sensor that mounts near the diff flange and is triggered by the flange bolts passing it.

There's a way, rest assured.

Kevin

[Smallfry]

Hi Kevin

I am going to fit it into a Triumph Herald, and am just getting the parts together to do it. I have got an Omega 2.5 engine, and also a Vectra version as well, and will have to make a suitable engine from bits of both in order to make it fit. I could get a 3 litre instead, but as the Herald will only weigh 2/3 rds of an Omega,I think it will be enough !

Biggest problem for me is going to be the electronics, as I dont yet know what I will need to make the engine run out of its orignal home, closely followed by the intake system. I know I can make the engine run without the multi rams, but I am concerned as to how much torque and power will be lost.

Sounds like a good solution for the speedo problem though !

[Marks DTM Calib]

To male it run you will need the immobilier transponder and ECU (from the engine donor car) plus a few extra wires to link them to the engine loom......not to hard actualy.

Christ knows what the rear end of a herald will do with 170bhp through it!

[Kevin Wood]

I am going to fit it into a Triumph Herald....

Fantastic! That should be a bonkers project [size=8]if it holds together[/size].

I don't know if you're planning to keep the existing instruments or change them. I'm using one of these:
http://www.merlinmotorsport.co.uk/p6221/VDO-100mm-SPEEDOMETER-0-150MPH/product_info.html?osCsid=ee8d146788ba684eaf3ec31453b64cc3

As I say, it takes an output from a VRS mounted near the flange bolts so I'm sure there's somewhere you could get a signal from. You can calibrate it over a wide range of "pulse per mile" rates so you should be able to get it working.

I believe you can get similar devices in authentic "Smiths" style as well.

It's always a tough one as to whether to keep the OEM engine management or roll your own. If you change enough (induction, exhausts, etc) and remove enough of the systems that the ECU communicates with (abs, etc.) it can get more troublesome trying to keep it happy than starting from scratch with an aftermarket ECU. In addition, if you change the engine's environment too much it may no longer be within the "fuel trim" range of the system...

Another thing to think about is that with an aftermarket injection system you could do away with the MAF sensor and use speed-density or alpha-n which may save you a bit of space.

Two options I'd consider are an Emerald http://www.emeraldm3d.com/ or, if you want to get your hands dirty, a Megasquirt http://www.megasquirt.info/. I run the latter on a Ford Zetec in my Westfield so drop me a PM if you want to have a natter about the options sometime.

Anyway, have fun and keep us updated on progress.

Kevin

[Kevin Wood]

Christ knows what the rear end of a herald will do with 170bhp through it!

I'm hoping it'll have something else back there so we never find out.

Handling was interesting with the original engines as it didn't take much torque through the rear shafts to lose all compliance in the back end.

Kevin

[Smallfry]

I have actually had several Herald/Vitesses, so the alledged bad handling is not a new thing to me at all. Actually, I think its one of those tales which has got better with the telling.

They ARE unforgiving at the very limit, but provided you follow the golden rule of finishing your braking before the turn, and never EVER let off the throttle in the bend, you will be fine.

One of my previous Heralds had a Rover V8 with an "almost" standard rear end, and it was not a problem. Because of the low diff ratio its top speed was only 80mph, but it got there quick !

[Kevin Wood]

I wish more modern cars were "unforgiving at the limit", to be honest.  [smiley=evil.gif]

Just remembered, there's some useful information Here: http://www.autobahnstormers.org/. Go to eligible cars then Omega B and pick a model. Lots of tech specs there including gearbox and diff ratios, etc.  

Kevin