Mbe check over and latest emissions test

[Matthew Poxon]

On the subject of MAP sensors I was under the impression that the MBE ECU TVR Power fitted to the RV8 cars did have a MAP sensor.

I stand to be corrected but below is a picture of a Griff with the new TVR Power MBE ECU fitted with what looks to be a MAP sensor:

[KateV8]

Our MBE defintely does have a MAP sensor but it's the 9A9 version so may be different to ClassicChimaera's.

[ClassicChimaera]

Oh, so that's a MAP sensor. Thankyou Mathew for that lovely pic, I wondered what that thing did it's another part of my precious MBE. LIKE A SWISS WATCH,,, Kin ell Al ,,, enough already.
Well I'll be, I'm a very happy boy today. Thanks for the good news.
Gosh I'm thick

Jason's lesson last week was glorious and set me up, i'll know all this come next Wednesday.
So it's taking maniflof pressure readings too, divi, the plastic vacuum pipe,,, its a bit of a give away.




I've tidied it all up since then too

Edited by ClassicChimaera on Saturday 14th January 14:41

[QBee]

"Maniflof" ?

Sounds like the first eruption of a teenage moustache.....

[Incognegro]

ClassicChimaera said:

As we know these Tvr's can be fragile so having as much information available to monitor its internals must be money well spent.

I grew up watching Star trec but I never thought I'd be in it.
Exciting developments.

I'm at Powers next Wednesday so I'll look out for your car

Weather held up and I felt brave. Argento made it to Powers safely and keys handed to Dom

[SILICONEKID345HP]

I thought Map sensors were for forced induction .

How does it work on tps and Map and what are the advantages?

I dont have one of those but did have one in the old megasquirt ECU.

[QBee]

SILICONEKID345HP said:

I thought Map sensors were for forced induction .

How does it work on tps and Map and what are the advantages?

I dont have one of those but did have one in the old megasquirt ECU.

Doesn't the map sensor connect to your satnav to help keep the car on the tarmac?

[SILICONEKID345HP]

QBee said:

SILICONEKID345HP said:

I thought Map sensors were for forced induction .

How does it work on tps and Map and what are the advantages?

I dont have one of those but did have one in the old megasquirt ECU.

Doesn't the map sensor connect to your satnav to help keep the car on the tarmac?

Im surprised yours even starts up on the cux

[Brithunter]

SILICONEKID345HP said:

I thought Map sensors were for forced induction .

How does it work on tps and Map and what are the advantages?

I dont have one of those but did have one in the old megasquirt ECU.

Not at all the later MGF's have a MAP sensor I think you will find on the manifold of the 1.8 litre K4 Series engines.

[SILICONEKID345HP]

Mine just runs on TPS , what am I missing out on without the MAP sensor.

[Sardonicus]

MAP/speed density is a just another way of monitoring what the engine is doing a bonus IMO trouble is if you run a hairy arsed cam you will either have to run a hybrid Alpha N set up or pure Alpha N if you run pure MAP the noisy vac/map signal will cause havoc with low speed drive-ability like it wont already be bad enough from your chosen cam profile so if its a choice between Alpha N Vs Vac/MAP/Speed density then Vac/MAP every time MAP/Vac control is essential for FI for ultimate engine feedback to the ECU

[ClassicChimaera]

SILICONEKID345HP said:

Mine just runs on TPS , what am I missing out on without the MAP sensor.

MAP = manifold absolute pressure.

Mbe off the top of my head,,,

Air goes past the air temp sensor then the throttle pot sensor then past the MAP sensor in the inlet manifold and into the engine.

The Ecu reads these sensors and in conguntion with the Rpm responses off the crank trigger wheel decides what fuel and timing to add at any given throttle position.

MAP reads air density so more info for the Ecu to make better decisions.
That's how I'm reading it. I often wonder how it ticks over from stone cold without a stepper, I think I'm starting to understand

[ClassicChimaera]

Sardonicus said:

MAP/speed density is a just another way of monitoring what the engine is doing a bonus IMO trouble is if you run a hairy arsed cam you will either have to run a hybrid Alpha N set up or pure Alpha N if you run pure MAP the noisy vac/map signal will cause havoc with low speed drive-ability like it wont already be bad enough from your chosen cam profile so if its a choice between Alpha N Vs Vac/MAP/Speed density then Vac/MAP every time MAP/Vac control is essential for FI for ultimate engine feedback to the ECU

Well I'll be, I understood that fully and know the reasons why Alpha N is a better solution when using high lift cams,

The manifold pressure on a high lift cam engine on induction stroke being so aggressive is large and the sensors struggle to understand the info.,,, I think. Pushed my luck now

[Sardonicus]

ClassicChimaera said:

I often wonder how it ticks over from stone cold without a stepper, I think I'm starting to understand

Decent AFR and lots of advance Alun nowt to do with running MAP

[ClassicChimaera]

Sardonicus said:

Decent AFR and lots of advance Alun nowt to do with running MAP

Ok. Makes sense

[ClassicChimaera]

Incognegro said:

Weather held up and I felt brave. Argento made it to Powers safely and keys handed to Dom

Yeeeeesssss
Everyone wants a Cerb, end of,,,,, watching this come together on such a futuristic car with great long doors
Must be a treat for all of us to witness. Argento will be rocking after this.
Really pleased you made the effort. Very exciting times

[SILICONEKID345HP]

So the tps is taking care of big changes because the Map is to slow and the Map is better than TPS for smaller changes or is that bos.

Edited by SILICONEKID345HP on Saturday 14th January 21:40

[ClassicChimaera]

Map is calculating manifold pressure and air speed/density so just more info for the Ecu to go on.

[SILICONEKID345HP]

ClassicChimaera said:

Map is calculating manifold pressure and air speed/density so just more info for the Ecu to go on.

Is it more difficult to map ?

[ClassicChimaera]

SILICONEKID345HP said:

Is it more difficult to map ?

Your taking the piss
You know all this but I'm enjoying learning from your attempts at numptie questions

Well it takes a deep understanding of timing for one thing, and yes it is harder to map I reckon, you have to set many parameters all the way up the Rev range.
Your using known factors and just adapting them to the spec of a particular engine.
Once mapped other than Lsmbda control it's set, but it's monitoring things and if it goes out of sinc by say 10% it will flag up an issue on the software. Jay puts in protection at all points on the map,,,, every 200 revs.
That's probably miles off but something like that

ETA so you have a controlled map but it will make changes to the map if things go out of line to compensate and the mapper can set the percentage that the Ecu will effect the mapping.
It just decides something's not right and goes to a safe set of parameters If the readings are getting to far out.

Edited by ClassicChimaera on Sunday 15th January 01:02

Edited by ClassicChimaera on Sunday 15th January 01:04