Dyno Runs

TVR Power Dyno Session

Following my writeup about the ACT twin throttle carbon fibre plenum I have been up to TVR Power and the car has been mapped by 14CUX guru Mark Adams.

Original plenum writeup

The last dyno result I had for the Griff was at the Growl in 2013 on North London Dyno rolling road. This was without the plenum and you can see the car was over fuelling so much so that the torque dripped.

2013-07-07 North London Dyno 1

Torque & AFR
2013-07-07 North London Dyno 2

2013 Griff Growl
Peak BHP – 226.6BHP Wheels (281.8 Flywheel)
Peak Torque – 342ft/lb

The twin throttle plenum and K&N flat panel filter were added in 2014 everything else on the car has remained the same since the dyno run in 2013. Mark Adams booked up a session at TVR Power yesterday to get the car mapped correctly with new plenum. I am always impressed with Mark’s work, peak power figures are all well and good when on full throttle but most importantly to me is how the car actually drives and this is where Mark excels, not only does he map the car for maximum power he also knows how to iron out all those annoyances such as shunting, hesitations, lumpy idles etc which become very tiresome around town and when stuck in traffic.

I have met Dom a few times but it was my first time up at Power and I was very impressed by the hospitality. Mark was mapping the car and Jason Oakley was operating the Dyno on the day so I had two TVR legends working on the car. After setting the car up Mark and Jason thoroughly checked the car over analysing the ignition and fuelling to make sure everything was working as it should. I asked Mark to perform a before and after run so I could compare.

TVR Power Dyno

First Run (before mapping)
2014-06-24 TVR Power Dyno Before

Final Run (after mapping)
2014-06-24 TVR Power Dyno After

After Mark had worked his magic and got the fuelling spot on the final run showed a further increase in BHP and torque.

2014 TVR Power
Peak BHP – 254.65BHP Wheels (309.95 Flywheel)
Peak Torque – 285.20ft/lb Wheels (347.15 Flywheel)

It is very difficult to accurately compare the pre plenum figures to post plenum as the readings are from different dynos on different days. The only way to accurately compare is to test back to back on the same dyno on the same day. Furthermore the fuelling was out in 2013 so the car would have certainly made more back then if this was sorted. TVR Power’s dyno figures where measured at the wheels whereas the Growl dyno measures at the wheels and then converts to a flywheel figure. The Growl Dyno Dynamics dyno read 226.6BHP at the wheels and converted this to a figure of 281.8BHP at the fly, as a percentage this works out as 21.7152%. I have applied the percentage to the TVR Power wheel BHP figures to compare flywheel figures:

Before plenum – Peak BHP – 226.6BHP Wheels (281.8 Flywheel)
After plenum – Peak BHP – 254.65BHP Wheels (309.95 Flywheel)

Having upgraded the AFM, injectors, fuel reg, plenum, trumpets and manifolds I am now in a position where there is no more power to be had from the original engine. Any further uplift in power will require an upgraded engine. Figures aside I am very pleased with the complete package, the car drives and performs well and I have the piece of mind that the fuelling is spot on so I can safely exercise the car on track.



Griffith Growl 2013 Dyno Run

I attended the Griffith Growl again this year, an annual event which sees a large number of owners meet at Ettington Chase.

Gary and Barry from North London Dyno were in attendance with their rolling road. Every year I put the Griff on the dyno to see if there is any difference from last year. Having upgraded the injectors, MAF and EPROM I was hoping for an increase on last year.

As Gary was driving the car onto the rollers Barry said that he thought the car smelt a bit rich. After completing two runs the graph indeed showed the car as running rich. Barry did comment that it didn’t look like a mapping issue but perhaps a fault elsewhere such as a sensor or a earth.

The figures were an improvement on last year with a max figures of 281.8BHP and torque 336ft/lb. As can be seen on the second graph the torque drops where the car is overfueling.

2013-07-07 North London Dyno 1 2013-07-07 North London Dyno 2

Despite the fact it is running rich the car still drives very nicely around town and certainly still pulls very well on full throttle so I will ask David Batty to have a look at the issue next time the car is in for a service.

HD link: http://www.youtube.com/watch?v=_lBe6VDVb6M&hd=1

John Barrans TVR Griffith 500 posted an epic result of 308BHP with 376ft/lb torque! John has a similar setup to mine in the respect of the larger injectors, MAFM, Mark Adams EPROM but has recently rebuilt his engine and changed the standard cam with a TVR Power 885 cam.

Ian Rose was also at the Growl this year with his recently built John Eales 5.15lire engine. Most impressive of all was the JE X-over manifold with Jenvey individual throttle bodies. Certainly food for thought…

Ian Rose JE Throttle Bodies

David Gerald had a trade stand at the Growl this year and amongst various other products had his Griffith brake upgrade kit on display. I have always had in the back of my mind about a brake upgrade, the standard brakes are fine for road use but they do fade quickly on track and I do find the brakes lack feel in that they do not inspire confidence and do not have enough initial ‘bite’.

Most aftermarket brake upgrades feature 300mm discs with do not fit under the standard 15″ front wheels. I am not a massive fan of aftermarket wheels and intend on keeping the original TVR Estoril wheels. David Gerald’s Alcon kit features 295mm discs and does fit underneath the standard wheels furthermore it is a direct bolt on kit.

Here is a link to the product on David’s site:


04-08-2013 23-45-29

Mapping session at Mech Repairs with Mark Adams

I had the ACT / Mark Adams Tornado tuning kit fitted to my Griff last month by David Batty. The kit included the higher flow rate spray pattern injectors, larger Bosch MAFM and updated Tornado EPROM. I already have the ACT carbon fibre plenum trumpets ACT manifolds, smooth bore induction hoses etc.

I booked a session with Rover V8 mapping guru Mark Adams at Mech Repairs in Cheltenham. The first couple of hours were spent with Mark and Brian from Mech completing a full diagnostic of the car. I was surprised at how much detail Mark and Brian went into testing the car before the mapping session. The ignition system, fuel system, EFI sensors and ECU, plugs and camshaft where all scrutinised. Mark and Brian did identify an issue with the coil, not outputting enough voltage, this was changed for a Bosch coil. Further inspection of the old coil showed that it was a non branded version and the seal had gone resulting in all the oil leaking out.

I asked Mark to run a power run on the car as is before any mapping took place as a control so I could see the difference once the car was mapped.

The initial run showed the car was running quite lean but was still making good power. Mark tells me that the dyno at Mech repairs reads about 21% under what most others do so based on the figure of 229BHP that equates to 277BHP which ties in with exactly what mine made on the North London Dyno at Griff Growl last year.

Initial Run

2013-04-05 Mech Repairs Dyno Initial Run

2013-04-05 Mech Repairs Dyno (2)

Mark increased the fueling and the power figure increased by 9BHP to 238BHP, but still running lean. Mark increased the fueling again and the BHP figure went up to 245BHP. Still not entirely happy Mark also adjusted the timing on the dizzy and now she was running spot on and made a final figure of 247BHP which + the 21% works out at 298.87BHP.

Final Run

2013-04-05 Mech Repairs Dyno Final Run

The following graph shows the before and after runs overlayed.


2013-04-05 Mech Repairs Dyno Run Comparison

I will be very interested to see what the car makes on the North London Dyno at the Growl this year.

More important than the increase of power is the fact that the car now drives very nicely indeed. The road manners are much improved, no shunting, no idle issues and no hunting. My car has always had an issue where if it is below freezing I cannot simply start the car and drive off I have to leave it running for a couple of minutes which amuses my neighbours no end. The reason for this is that if I go anywhere near the accelerator it floods and stalls. Since having Mark’s chip and custom map on there I can start the car and drive straight away without any issues. The car had also recently developed a very irritating idle issue where it would idle at 2k which made it very difficult to control at low speeds. I am pleased to report that this issue has also bee resolved.

For anyone thinking about having this done I whole hardheartedly recommend it. Watching Mark work his magic is fascinating and he certainly is a master of his craft.

So what next…..
Maybe a new cam, ACT twin throttle Carbon plenum and an Omex ignition processor to complement the 14CUX fueling. Probably not until next year now though.

Griffith Growl 2010 Dyno Run

Having purchased a Griff it would be rude not to attend the Griffith Growl event which sees a large number of owners meet at Ettington Chase. The annual event normally attracts over 100 TVR Griffiths and various other TVRs, there also also a number a trade stands.

Not having had the car on a rolling road before I was interested to see what figures it pulled on the dyno and how that compared to other cars that also ran on the same day. The dyno was run by North London Dyno (ex Crazy Horses).

Griff Growl 2010 Dyno

The graphs showed a nice flat torque curve with over 280ft/lb torque from 1500RPM peaking at 300ft/lb around 3500RPM. Maximum power output 262.5BHP at 5000RPM.

100731 North London Dyno Centre BHP vs Ftlb

The air fuel ratio showed the car was running slightly rich but overall not too bad.

100731 North London Dyno Centre BHP vs AFR