Grinnall vs AC Cobra

[Wayne S]

Just surfing through the old You Tube and found a nice shot of me having a tussle with an AC Cobra down the Mulsanne straight at Le Mans Classic the other week. Notice how super fast we look compared to all other Triumphs on the circuit. Blink and you'll miss me as by the time we got to the pit straight im long gone.

Skip to 5 min 20 secs in.

http://www.youtube.com/watch?v=iq7aEh-TQPo

Suffice to say that 2 laps later when we were pulled in, he was still behind me [:D]

This was lap one and was ridden with slow traffic, later it cleared and I managed my 140 MPH moment [}:)]

Purple 2.0 Litre DHC Grinnall
Red 4.0 Litre V8 DHC Grinnall (with huuuuuge arches...!)

[FI Spyder]

You went by them like they were standing still.

TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

[busheytrader]

nice growl

TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, Single Pipe Exh, 3.08 Rear, 200lb Spax & Solid Bushes, Anti- Dive, Granada Vented Discs & Calipers, Green Stuff, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AllyCat 5 Spokes. No Door Stickers.

[PeterTR7V8]

Nothing like a nice Sunday drive!

What is the top speed of your Grinnall?

[Wayne S]

Im not sure to be honest Peter, at 140 it felt like it had a lot more to give and still felt stable on the road pulling just over 5000 rpm, im pretty sure 150 MPH isnt out of the question but I kept getting stuck in traffic or running out of road.

Purple 2.0 Litre DHC Grinnall
Red 4.0 Litre V8 DHC Grinnall (with huuuuuge arches...!)

[PeterTR7V8]

You must have some tall gears.

I'm at around 3000rpm at 110kph/68mph so I figure my top speed at a max 5500rpm would only be about 200kph/125mph. Strange that I haven't tested that theory yet.

I need a 6th gear!

Interesting to hear the Spitfire pilot complain his brakes were shot after half a lap.

[zekow1]

Wayne
I am speechless
You where definetly cooking man
.
i have a question for you .
Where can you get those lights you have on your cars?????
the alongated ones??
Have fun
Be safe
Zeke

[Wayne S]

Peter, 5th gear in the V8 is huge and only really a fuel saver for motorway driving. With shorter ratio's though you probably have the edge on acceleration and if it tops out at about 125 thats more than adequate for normal road driving I would have thought.

My brakes but pretty finished by the end of Lap 2 as well despite 4 pot calipers and EBC pads!

The rear lights zekow1 were added by Grinnall when he built the cars. They are originally from the Rover SD1 but were used upside down on the Lotus Espirit as well.

Just noticed that Spitfire has a 6 cylinder engine in it as well!

Purple 2.0 Litre DHC Grinnall
Red 4.0 Litre V8 DHC Grinnall (with huuuuuge arches...!)

[PeterTR7V8]

What gearbox do you have?

In NZ you rarely find a stretch of road straight enough to go over 100MPH but I can dream can't I [:)]

[Sondar]

My V8 with the LT77 5 speed gearbox and a 3.08 rear axle runs about 25mph per 1,000 rpm - which I guess equates to a theoretical top speed of 150mph at 6,000, subject to overcoming wind resistance.

Haven't tested that out yet, but I did get past 130 and still climbing (with the top down) before I got too worried about the local police... I'd guess that top down, it might make close to 140, probably a few more with the top up.

Sondar

[Wayne S]

My gearbox will be the same as yours Peter, the same old LT77 5 speed. What will be different is the rear axle ratio. During Grinnalls conversion of the car they fitted mine with the Rover SD1 rear axle which has (correct me if im wrong) a 3.08 ratio diff rather than the 3.9 of the 5 speed TR7 which is the one I suspect you have.

It also gives me a wider track and 5 stud hubs.

Purple 2.0 Litre DHC Grinnall
Red 4.0 Litre V8 DHC Grinnall (with huuuuuge arches...!)

[PeterTR7V8]

Wayne, I have the standard TR7 diff/axle BUT I have a Toyota W57 box which, I want to point out, is not the trouble free, wonder box it is made out to be. 2nd gear needs a new synchro & the wrong oil turns the whole thing into a fork drawer.

It is better than the old LT77 that was in it. That thing needed written notice to change gears.

So final transmission ratio & an extra 500RPM is the secret to warp speed.

[paul w]

Great stuff Wayne,ya certainly prooved ya can go fast...all ya gotta
do now is get those brakes to slow it down!

See ya. Paul