Griff Rolling Road Shoot Out - Jan 2007

I Every now and again, owners of “fettled” cars get together to find out whether the time, effort, not to mention cash, is getting them the results that they are hoping for. The may have engine dyno figures, a.n. other Rolling Road figures or just be curious…but the only way to really tell how your car would perform against another is to get them all in one place, on the same day. A “Shoot-out”.

Ben (Grifter) was one such owner. His own 4.3 pre-cat had never been tested. He’d bought and lightly restored the car over a couple of years, but had always been intrigued at whether the “Pre-cat” that he had chosen over a “500” was really that far behind. A mate of Mike (Mongoose) they got together and decided to arrange a shoot-out to see how things had progressed over the last couple of years.

To set the scene a bit here, the last Griff shoot out was only a few miles up the road at Mech Repairs at Gloucester in 2003. This was chosen as it was handy and it was one of the roads that Mark Adams (Tornado Chip Guru) used to set up his cars. The Monster Griff was one player (whilst in JE twin plenum, big injector V8D  stage III heads 404H guise) along with Simon (ACT twin plenum – std injectors) and another Andy (complete ACT carbon triple/act exhaust, big injectors kitchen sink). There were the usual cam changes etc, my car was one of those used by “top bod” Rob Robertson to develop the 404 and 404H cams etc, mainly due to the fact that it did so many road and track miles and any issue would be seen very quickly etc. To cut along story short, the cars came out as follows.

Andy (triple ACT)        @315bhp (strong, flat graph)
Andy (JE twin plenum) @308bhp (strong, flat graph)
Simon (twin plenum)     @306bhp (strong, flat graph)

So the scene is set. Everyone arrived at Interpro at Thornbury near Bristol at 9ish. The cars came from all over the south. Some (CliveF, Isle of Wight) came some distance but everyone made it roughly on time…with the occasional hic-cup! First up was Ben (only fair) but it was short lived as his car was “pinking” and was removed to prevent damage…it would be back! “Pinking” is the sound an engine makes when the charge ignites too soon and the explosion hits the piston as its still rising. Not good. Usually caused in tvrs by running too much ignition advance (which increases further with the revs to cause a greater problem) or poor fuel. Often running a good, high octane fuel such as “Shell Optimax” will cure this, but its best to get the ignition timing/distributor checked anyway. The “pinking” thing was to affect several cars that day, as was the quick way the cars were been tied in. tvrs often have a problem as they are light and low. This will cause the tyres to slip on the rollers giving low readings…we would see a lot of that too. Anyway, here are the figures, with some notes on performance.

Jefsy	354 (projected due to slip, “Robbo” 5.4L engine)
Mongoose	345  (original bottom end with V8D heads, Cam and Jools fettled)
2munkys	329 (288 [corrected to 329bhp on another verified road with no slippage])
Bluebottle	318 (225 [as above, 318bhp from a Dulford rebuilt std 5L, with breathed on heads])
ZZ Top	279 (slipping again, figures to come)
GarryM	266
flyin banana	264
LordGrover	256 (4.3 stonking run)
Grifter	250 (4.3 another great run)
Rapidrental	250 (pinking stop @4krpm, no further info)
clivef	238 (pinking - as above)
MarkCosh	229 (as above)
pjac67	198 (strange one this, no slip, sounded fine, just didn't pull the numbers...wants a recount)

As you can see when comparing the two sets of results, things are indeed moving on. Continued developments are seeing some very strong engines with another four cars joining the Mark Adams named “monster list” for RV8 cars with a genuine 300+bhp. There were only around 12 of these when my car first joined the list and its great to see another bunch of dedicated owners joining the Hall of Fame! The only caviat I would enter is the way the information is presented on the road. The use of speed against BHP does not display the true engine characteristics and show how strongly they would pull on the open road. A graph showing bhp against torque shows accurately how well the car would pull in the mid range as well as at the top end. Still, can’t have everything!

All the best till next time

Andy
(BTW, the “Monster Griff” couldn’t be there as it is currently being prepared for the tvr Challenge Race series)

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