Tornado Chips

[Chunky Dave]

Morning all.
Having now covered 500 odd miles since I collected my 4.0 ltr I have realised that maybe it needs looking at. Having never owned a car like this, every time I get in it I notice different things. For instance, when I first start it up and drive it, it seems to shunt and not drive smoothly until its warmed up. I was told by a friend that a Tornado chip would cure this. Having done a little research it would appear that the jury is out on the chip and also once fitted the car needs to go on a dyno.
My car is as far as in a standard configuration and I'm not aware that its had any engine mods. Do you think the chip would improve the drive-ability of my car or do I need to look else where?
Dave

[blitzracing]

The Tornado chips are a huge improvement over Range Rover fuel maps, but less so on the already modified TVR chips. Simply plugging in a £400 chip in hope of a cure is a very crude way of trying to resolve any shunting- first thing is to ensure all the service items are up to scrach, and that you have run at least one bottle of injector cleaner through the tank. Shunting is due to a poor mixture burn, and anything that helps improve this can reduce it, but you also need to look closely at what the ECU is doing fuel wise as well. Any sensor that is out of spec' can cause the engine to fuel incorrectly, and the ecu tries to compensate to control the mixture, and this can lead to shunting. The Steve heath ECU mate will give you this data, or the freeware RoverGauge software.

Diagnostics covered here:

http://www.g33.co.uk/fuel_injection.htm

[ChimpofDarkness]

My comments here may be of interest?

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

Happy to discuss the package off-line if you prefer.

Dave.

[Chunky Dave]

blitzracing said:

The Tornado chips are a huge improvement over Range Rover fuel maps, but less so on the already modified TVR chips. Simply plugging in a £400 chip in hope of a cure is a very crude way of trying to resolve any shunting- first thing is to ensure all the service items are up to scrach, and that you have run at least one bottle of injector cleaner through the tank. Shunting is due to a poor mixture burn, and anything that helps improve this can reduce it, but you also need to look closely at what the ECU is doing fuel wise as well. Any sensor that is out of spec' can cause the engine to fuel incorrectly, and the ecu tries to compensate to control the mixture, and this can lead to shunting. The Steve heath ECU mate will give you this data, or the freeware RoverGauge software.

Diagnostics covered here:

http://www.g33.co.uk/fuel_injection.htm

Thanks for your reply, I think its beyond me so a trip to a dyno looks like the way forward.

[SILICONEKID340HP]

Chunky Dave said:

blitzracing said:

The Tornado chips are a huge improvement over Range Rover fuel maps, but less so on the already modified TVR chips. Simply plugging in a £400 chip in hope of a cure is a very crude way of trying to resolve any shunting- first thing is to ensure all the service items are up to scrach, and that you have run at least one bottle of injector cleaner through the tank. Shunting is due to a poor mixture burn, and anything that helps improve this can reduce it, but you also need to look closely at what the ECU is doing fuel wise as well. Any sensor that is out of spec' can cause the engine to fuel incorrectly, and the ecu tries to compensate to control the mixture, and this can lead to shunting. The Steve heath ECU mate will give you this data, or the freeware RoverGauge software.

Diagnostics covered here:

http://www.g33.co.uk/fuel_injection.htm

Thanks for your reply, I think its beyond me so a trip to a dyno looks like the way forward.

Its the plenum design and sporty cams which cause the problem..

[blitzracing]

If it where that simple they would all do it all the time- so there are other factors involved as well.

[blitzracing]

Chunky Dave said:

Thanks for your reply, I think its beyond me so a trip to a dyno looks like the way forward.

Problem is a dyno may not show you anything conclusive- you may see some poor gas results, but it wont show you the cause, and there are only a few things that can be tweaked like Throttle pot and ignition timing- the rest is self calibrating depending on sensor inputs.

[Chunky Dave]

blitzracing said:

Problem is a dyno may not show you anything conclusive- you may see some poor gas results, but it wont show you the cause, and there are only a few things that can be tweaked like Throttle pot and ignition timing- the rest is self calibrating depending on sensor inputs.

Sadly my spanner skill's are not up this level of diagnostics. Naively I thought getting a car from a TVR specialist garage with a full history was the way forward for a TVR virgin. Didn't expect to be this far out of my depth.....

[OleVix]

Didnt changing the coolant temp sensor fix a lot of shunting issues??

[leaderb]

I had the Torqueflow airflow upgrade which massively improved my car's shunting. I know some don't rate the conversion but it's certainly worked for me.

[Chunky Dave]

leaderb said:

I had the Torqueflow airflow upgrade which massively improved my car's shunting. I know some don't rate the conversion but it's certainly worked for me.

Why do people not rate the upgrade if it works?

[Simon says]

blitzracing said:

If it where that simple they would all do it all the time- so there are other factors involved as well.

< This, backed up by some of the stock 400's shunting more than the 400HC's or spikier cammed models and HC's are over cammed which should make things far worse but it don't more a case of how well the motor is coping with the plenum contamination at low speed Vs how well the fuel is being metered, engine condition, stretched timing chains, ignition timing, injector condition etc, etc, what cures one car may not cure another I can simulate the shunting quite easily if I lean the mixture around 1600-2000rpm and advance the timing a tad on the MS the shunting don't just go away unless you start changing induction/cam combinations in my view

Edited by Simon says on Wednesday 25th July 09:49

[SILICONEKID340HP]

[quote=Simon says] This, backed up by some of the stock 400's shunting more than the 400HC's or spikier cammed models and HC's are over cammed which should make things far worse but it don't more a case of how well the motor is coping with the plenum contamination at low speed Vs how well the fuel is being metered, engine condition, stretched timing chains, ignition timing, injector condition etc, etc, what cures one car may not cure another I can simulate the shunting quite easily if I lean the mixture around 1600-2000rpm and advance the timing a tad on the MS the shunting don't just go away unless you start changing induction/cam combinations in my view




You can`t cure the shunting with an after market ECU only mask it ..Problem is you will be cruising around town at 14afr or richer ..

I still get it up to 30mph so the answer is to go in to third gear

[Simon says]

14 AFR is not rich Daz that's 1.5 CO approx which is lean-ish I run around 13.5 AFR 2.5% CO in the dreaded lurch area on my engine and the lurching is barely noticeable I also pulled out some advance too from the map I have come to the conclusion the RV8 loves fuel low down with a plenum and its associated problems so now I can have my cake and eat it that's the beauty of MS

Edited by Simon says on Wednesday 25th July 12:24

[blitzracing]

leaderb said:

I had the Torqueflow airflow upgrade which massively improved my car's shunting. I know some don't rate the conversion but it's certainly worked for me.

One of the effects is Torqueflow has a tendency to overfuel the engine at low speed as the AFM output is skewed. This can be enough to overide the ECU's abilities to correct the mixture to keep the emmissions low, so you end up with a richer mixture, and more fuel on the whole means less shunting- its not really a design feature as such- just the way it worked out. You can do the same thing by running the non catalyst fuel map, and richen the mixture with the adjustment screw on the side of the AFM- but then you may end up with the wrong fuel map altogether, and the catalysts wont like it.

The bit about the temp sender has the same effect- if its reading a higher temperature than it should the ECU will lean the mixture out to start with , and then it will shunt as the ECU tries to correct the mixture post combustion. As a thought on this, id think it perfectly possible by adding or removing resistance from the temp sender to trim the fueling to an extent to "dial out" the shunting region. Ive not tried this, but trying to do it with the AFM voltages is a bit like streaching a rubber band- the ECU keeps correcting for as long as it can- then suddently it lets go, and the mixture goes out of control.

[ChimpofDarkness]

Simon says said:

14 AFR is not rich Daz that's 1.5 CO approx which is lean-ish I run around 13.5 AFR 2.5% CO in the dreaded lurch area on my engine and the lurching is barely noticeable I also pulled out some advance too from the map I have come to the conclusion the RV8 loves fuel low down with a plenum and its associated problems so now I can have my cake and eat it that's the beauty of MS

Edited by Simon says on Wednesday 25th July 12:24

Interesting Simon, and supports what I saw on the AFR when I ran my Mark Adams Tornado chip back to back with the TVR chip.



The Tornado chip seems to throw in a bit more fuel just where the TVR chip goes weak.

I don't think it's a coincidence this is also at the same RPM band where shunting rears it's ugly head on these cars.

It certainly seems extra fuel is masking the shunting.

On a separate point, what AFR are you running at light load cruising?

I see no issue with going quite lean under these circumstances as I'm running no cats.

Pushing things to the point of lean surge then backing it off a tad should give me some nice economy improvements from my Canems.

Thoughts?

[ChimpofDarkness]

Simon says said:

Never seen those graphs before Dave

Edited by Simon says on Wednesday 25th July 14:09

Glad you liked my old graph mate, Daz will be along in a minute to tell me there is a rabbit at the end of the MA one

I had the very light load AFR chat with the Lloyd boys when I dropped the car off with them two weeks ago.

We all agreed with no cats in residence there was no danger in pushing the AFR quite lean on light load cruise.

I got the call yesterday to say the car happily runs sweet as a nut at 17:1 under these conditions (70-75mph).

They seemed quite impressed that my engine demonstrated no hint of lean surge or stumbling with a 17:1 AFR, they also suggested my Vectra injectors may be helping?

All I know is the sun is out & I want my car back now, I seldom leave it two weeks without taking it for a blast so the urge is very strong.

Roll on Friday

[Chunky Dave]

SILICONEKID340HP]imon says said:

This, backed up by some of the stock 400's shunting more than the 400HC's or spikier cammed models and HC's are over cammed which should make things far worse but it don't more a case of how well the motor is coping with the plenum contamination at low speed Vs how well the fuel is being metered, engine condition, stretched timing chains, ignition timing, injector condition etc, etc, what cures one car may not cure another I can simulate the shunting quite easily if I lean the mixture around 1600-2000rpm and advance the timing a tad on the MS the shunting don't just go away unless you start changing induction/cam combinations in my view




You can`t cure the shunting with an after market ECU only mask it ..Problem is you will be cruising around town at 14afr or richer ..

I still get it up to 30mph so the answer is to go in to third gear

Thats what I've been doing Siliconekid, just thought it wasn't right and perhaps it was (A) my driving or (B) problem with the car?

[Simon says]

ChimpofDarkness said:

Simon says said:

Never seen those graphs before Dave

Edited by Simon says on Wednesday 25th July 14:09

Glad you liked my old graph mate, Daz will be along in a minute to tell me there is a rabbit at the end of the MA one

I had the very light load AFR chat with the Lloyd boys when I dropped the car off with them two weeks ago.

We all agreed with no cats in residence there was no danger in pushing the AFR quite lean on light load cruise.

I got the call yesterday to say the car happily runs sweet as a nut at 17:1 under these conditions (70-75mph).

They seemed quite impressed that my engine demonstrated no hint of lean surge or stumbling with a 17:1 AFR, they also suggested my Vectra injectors may be helping?

All I know is the sun is out & I want my car back now, I seldom leave it two weeks without taking it for a blast so the urge is very strong.

Roll on Friday

Mmm must admit I need to retune my VE table now anyway as I have different Inj's too since my car was last on Tarmac I know I at to knock off around 10% off the VE at idle to low speed since

[SILICONEKID340HP]

17.1 on light load seems a bit weak ,been told not to go over 15.5 . Think you need to ask the more qualified.

70mph in fith should be around 14.7 ,its not that light load..

next post "i think my pistons have melted"