Members Page/David Blades - VEMS wiki www.vems.hu

About time I got started... (Again)

TVR Regeneration

It's been over 10 years since I put a VEMS in my TVR. It was used daily until 2014 when I built it a new engine. I ran it as a weekend car for 2015 and then put it in storage. Now it's time to get it back on the road where it belongs while there's still petrol to burn.

MembersPage/DavidBlades/Regeneration

The History

I have a TVR Griffith 500. It's a great car, but could be so much better with the right engine management.

My aims are to:

Increase my knowledge of engines and mapping
Make the car easier to maintain and modify
Avoid potential problems with obsolete parts
Gain more power from the engine while using less fuel :-)
Aid with the development of VEMS

A few words on the car

It's a light (1078kg) 2 seater convertable with a 5 litre Rover v8 engine (only 2 valves per cyl :-( ) made by a small company in Blackpool. There are no active safety features at all, so you have to drive it properly.

Modifications to date are uprated suspension, uprated brakes, polybushes and a large alloy radiator.

VEMS setup

Since I'm very time limited for the moment, I've gone for a fully assembled genboard 3.3 with all the bells and whistles.

I plan to have:

the usual sensors (MAP, IAT etc...)
fully sequential ignition and injection
2 WBO2s
dual knock sensor (even having 1 is an improvement!!)
- 1 acoustic is supported, 2 channels require firmware mod
- Ion Sensing needs new hardware
- OK, forget ION sense for now. 1 acoustic is good enough.
EGT

Trigger setup

Primary: 36-1 tooth wheel on crank, and Ford VR sensor

Secondary: modified distributor with hall sensor - the advance and reterd mechanism will be locked and the factory sensor for the timing will be modified to produce one pulse per rotation instead of the usual 4. (I may make this neater in future and put something directly on the cam wheel as this will be 0.01% more efficient ;-) )

Order of work

Get VEMS up and running in place of the Lucas 14CUX using the basic sensors. This will be injection only, running sequential ignition
Replace ignition system with 8 coilpacks. )Shame Subaru ones don't fit - I've got loads of them.)
Start to add the "extras" like WBO2
Do some tuning :-D

Update on this:

I'm through the first stage of basic sensors and running in sequential mode, but the injectors are not aligned with the valves.
Coils fitted and working.
Some extras added - single WBO2 fitted, waiting for the second one.
Large injectors fitted for future plans. Much better than the standard ones.
Some tuning of ECU done. Car goes quite well!
Performance exhaust manifolds fitted

Tuning

New exhaust manifolds will find their way on the car as the original ones aren't the best design. Also, the intake system could be redesigned to use 8 throttle bodies. Plenty of scope when there's a nice ECU dealing with it all.

Working on a new twin throttlebody plenum. Not happy with the 8 TB solutions I've seen yet, so this will do until I have time to plan more.

Completion Dates

Target date for having fully complient system for UK emissions tests is November 2006. This is now "unachieved" as I have no cats in the car for the moment.

Have coils & big injectors fitted by May Achieved

Running by June Achieved

Fully mapped by July. Ongoing - delay from exhaust problems

pushed this to end of July/beginning of August. Mapping is "good enough" for the moment

Rolling Road session booked for beginning of August.

Now rolling roaded - the car produced 260 bhp @5500 RPM and 320 ftlbs @ 3000 RPM. Not quite what I wanted, but it highlighted some fundimental problems with the design of the intake manifold & induction system. See the non-vems related pages for more details.

New inlet manifold designed and fitted. A little more rolling road time has resulted in a significant improvement.

Shortly after the above run, the clutch died, followed by the diff. This took a couple of months to source parts and repair. Obsolescence is not a nice thing.

The torque plot looks a lot cleaner now there's no slip.

The steep dropoff at the top end is mainly due to using 95 RON fuel. There should be a bit more power from more ignition advance, but there's no point for day-to-day running.

The mixture settings measured by the dyno were pretty good.

Other plans

One goal is to reduce the cars fuel consumption. To this end, I will be investigating "displacement on demand" - ie not fuelling certain cylinders depending on the engine loading. This nicely ties in with the actuation routines for traction control - another thing I plan to look at next year. Also considering running on E85 fuel.

Update: Nothing new here, other than I've found (but not fitted) the sensors I need. The plan is to fit these during the body-off restoration that is happening this winter.

Body-off restoration completed. Car looks like new underneath now.

Milestones along the way...

Fitting & testing the crank & cam triggers: MembersPage/DavidBlades/TrigTest

Fitting and testing other sensors: MembersPage/DavidBlades/SenTest

Injector Setup & Config file: MembersPage/DavidBlades/InjSetup

VE, Lambda tables & tuning the fuel: MembersPage/DavidBlades/FuelTest

Starting and Warm-up: MembersPage/DavidBlades/StartingWarmup

Acceleration Enrichment: MembersPage/DavidBlades/AccelEnrich

Idle control: MembersPage/DavidBlades/IdleControl

Cooling fan control & other ancilliaries: MembersPage/DavidBlades/FanTest

Fitting Ignition system: MembersPage/DavidBlades/IgnSetup

Non VEMS related issues: MembersPage/DavidBlades/NonVems