K series Lambda probe

[tom7]

I've just spoken to powerspeed about a new exhaust (thanks Dave H) and it dawned on me that as I'll be sticking with a MEMS ECU for the moment, what do I do with the lambda probe?

Does MEMS need it ot operate?

Should I have it in No 4 primary?

Should I have it at the 2-into-1 intersection?

Do I need it at all? (It will remain attached to the harness)

I plan to upgrade to emerald at some point and am aware I need it for some mapping, I will also be keeping the cat exhaust for future MOT times etc.

 

Any advice gratefully recieved.

 

Tom

[V7 SLR]

Seems a shame to butcher the new exhaust to satisfy a limited timespan requirement for the MEMS. You will need it. If you leave it connected, but not in the exhaust the MEMS will get all confused. Why not stick with the original exhaust until you have the Emerald? Saves you having to have the Lambda for evermore...

 

Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours

 

[robmar]

I have now run my powerspeed exhaust on my caterham without the lambda attached (it is somwhere in a box in the garage) for 6 months and the only noticed problems are when starting from cold, it won't idle which ain't surprising.

 

It is on my list of things to do BTW

 

rob

[tom7]

I suppose my question stems from a lack of understanding of what the lambda 'actually' does. I have seen examples of exhausts with the facility to screw-in the probe as required, but replaced by a plug when not in use .

Rob, was the exhaust mod in isolation? What difference did you notice in the performance, mine is a standard 1.8K (at the moment), I'm looking forward to bit of extra GO

 

Tom

[V7 SLR]

Tom, I've said this before, but why not visit us at the Worcs L7 club meeting in Redditch? There's a few people from around the area, including one chap building an R400 in Monkspath, Solihull.

 

Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours

 

[JAG]

Whilst at University I ran an experiment on a K series engine, 1400cc.

 

When I analysed the exhaust gas output I realised that the engine was running a little rich, after speaking to the Technician on the test cell it turned out that the Lambda sensor wasn't working on the engine I tested. It hadn't been working since the University were given the engine.

 

The upshot is that the MEMS ECU didn't care if the Lambda sensor was there or not. If there was no Lambda sensor signal it used a default value for the mixture setting that ensured that the engine ran slightly rich at all throttle settings, about 5% IIRC.

 

V7 SLR, I'm close to Redditch and would like to attend the local area meet. Where and when will I find you guys???

 

JAG

[V7 SLR]

We're at the Brook Inn, Elcocks Brook on the second Wednesday of each month. Alternatively, I'm free most Thursday nights and weekends if you want to pop over to my house. My phone number is in the Area Meetings list here.

 

Elcocks Brook is show at Multimap: We are here.

 

Nig.

 

Worcs L7 club joint AO.//Membership No. 4379//Azure Blue SLR No. 0077//Se7ens List Tours

 

[tom7]

Nig,

Thanks for the invite, unfortunately I'm out of the country for the 2nd week of November but will make every effort to make December's meet.

A natter in the meantime would be most welcome. I'll give you a call next week. I, too am in Monkspath, so I suppose I should search out the R400, or perhaps you could make an introduction. December meet?

 

Cheers

 

Tom

[Bob Corb]

You should keep the lamdba sensor fitted in runner 4 whilst not in mot mode, this will allow the ems to make fine tuning adjustments to ensure good fuel economy at cruise and low load. I assume for MOT you will have to refit the std exhaust and cat to pass emmisions therefore you'll need to make sure that the Emerald runs acceptably on std exh with the cat. The K series can run a bit rich on cyl 4 if memory serves so you are less likely to pass MOT keeping the Lambda sensor in that runner. This is why SLRs and R500s have the boss in runner four for non cat use (track use only officer) and a boss in the collector/cat for mot time. Now that the emisions regs have been tightened for post SVA cars you should consider your options carefully

 

BC

[Rob Walker]

Bob,

 

Could you enlighten me as how the regs have been amended re emission testing on Post SVA`d cars. I presume the pre SVA `d cars are still only liable to the 1975 visual smoke test if amature built?

 

Cheers

 

Rob

[robmar]

Tom - yep I added the exhaust in isolation to my 1.6SS superlight

 

as for empirical eveidence for increase in bhp or torque I have none, it has never been on the rollers. However it does feel like it has more umph 😬 it does sound good 😬 and looks the biz in black camcoat 😬 😬

 

I plan to go to an emerald when there is a production unit to mate the EU3 loom to it

 

as for fuel economy it does not seem to have got worse in fact at cruising below 4500 rpm it seems better!

 

rob

 

Edited by - robmar on 30 Oct 2002 15:39:50

[tom7]

From what Bob Corb has said, I've interpreted this as " make sure you get a boss in both No.4 primary for 'normal' running and the 2-into-1 collector for MOT time.

As a last resort I suppose I could download a map to the emerald for the standard exhaust with cat for MOT time, and reload the performance map afterwards.

Is my understanding correct? How do other emerald users get on at MOT time?

 

Tom

[Richard J Darnell]

I'm in the same postion as you Tom ie. I have a powerspeed exhaust on order (as part of the bulk-buy) and the standard Rover (supersport) MEMS.

 

When I spoke to powerspeed they implied the default position for the Lambda is on the outside of the car close to the 2-into-1 collector.

 

I understand that they are now fitting this so that the lambda input is between the exhaust and the side of the car so that you cannot see it side-on. Assuming this looks neat then I am guessing it is the best option, but please tell me if you know different.

 

If after fitting an Emerald ecu you no longer need the lambda, I assume you can screw in a blanking plug.

[tom7]

I dont mind the lambda input on top (as in the pictures) i.e. so that the sensor would be vertical, this would be for MOT time only and the wiring can be wherever. During 'normal' running I would blank this off and fit the lambda in No.4 as it is now. It seems like a good idea get a boss on No.4 primary anyway, it cant be that hard/expensive to do. If you dont specify one at this stage then you've lost the chance. I havn't ordered mine yet, but will be asking fro 2 bosses.

 

Tom

[Bob Corb]

The emissions regs for amateur built vehicles has changed slightly, those that go through SVA must now pass the same std that was enforced at SVA time at least thats what I interepreted from Caterhams own posting recently on this forum as shown below. Pre SVA cars are unaffected.

 

Tom, you've got the right idea re positioning the sensors. The post collector one on the R500 is inclined at 45° between vertically down and to the car. Its very inconspicuous in this position. You're Emerald map will probably be okay for the MOT test points. Just make sure the fuelling is in closed loop (lambda feedback) mode and you'll be fine.

 

BC

 

 

Caterham Aftersales posting from 25 Sept 2002---

 

"As if we didn't have enough confusion with SVA and its perpetually moving goalposts ("...but the manual says..." - "ah, but we had a memo yesterday telling us to interpret it this way, it supercedes last weeks memo telling us to interpret it the other way...") it looks like we are heading for something similar with MOT.

 

Last June I posted a message to clarify that amateur built cars, regardless of age, are to be tested as pre-1975 (section 6.4). However, I stated that this position may change for cars that were SVA'd with a cat.

 

Now it's changed. A bit. The totally revised manual still has the above clause (now section 7.3 page 9, in the box), but the accompanying manual 'IN SERVICE EXHAUST EMISSIONS', page 2 it adds "except those, which from 1 May 1998 are required to obtain Single Vehicle Approval"

 

Whilst we are seeking clarification from the VI, who seem as confused as us, it looks like it will be down to the individual tester to decide, just like SVA.

 

If you would like to go down fighting, then only cars where the sixth digit of the chassis number is an 'S' are factory built + SVA'd and everything else is considered amateur built. Try to refer them to the chassis plate and not the V5 as this also shows the emissions tests applicable at SVA - once they've seen that it is hard to persuade them it should be anything else!

 

Note: This applies only to Rover engined cars.

 

If you still have problems, we are here to help, drop me a line at aftersales@caterham.co.uk and we'll do what we can. I'll post an update when I know what the hell is going on!

 

SIMON LAMBERT

Aftersales Manager"