Top Speed

[sw2373]

I was out at the weekend, went for a trip down to Switzerland (Only 1.5 hours away...) it was also the first time I was mad enough to try and see how fast she was!!!

Well,I took a picture at 5,000rpm in fifth doing 140mph (very loud!!! alightly unstable) so had to put both hands back on the wheel!!!

Got to about 6000rpm reading and about 162mph according to the speedo... has anyone actually got 167mph out of theirs?

All I have to say about it is, a Porsche Boxster S was sticking with me accelerating in fifth from 120mph upwards..!!! Dissapointing...

[Nano2nd]

i saw an indicated 165mph on a 500 speedo at brunters oh and that was with the roof off!

i doubt that it reallywas 165mph is real terms though as speedos tend to be optimistic at high speed...

[donatien]

To get 167 in a standard 5.0 you'd probably have to be bouncing of the rev limiter at around 6k rpm. By then I suspect the power could have dropped off at least 50 bhp (it goes down quick after peak at 5500)

If it was geared slightly longer it could maybe make 170 in top if 170 was geared to max power.

Or then again it might not!

Just my 2p.

Dave

[angusfaldo]

donatien said:

To get 167 in a standard 5.0 you'd probably have to be bouncing of the rev limiter at around 6k rpm. By then I suspect the power could have dropped off at least 50 bhp (it goes down quick after peak at 5500) If it was geared slightly longer it could maybe make 170 in top if 170 was geared to max power. Or then again it might not! Just my 2p. Dave

But the rev limiter on a Griff is at 6800 isn't it? Which is why Steve's book advises caution because the engine shouldn't really take any more than 6200.

Steve can you clarify?

[beano500]

I think the limiter varies from one car to the next - mine cuts in about 6200......


..............with associated whiplash injuries !

>> Edited by beano500 on Thursday 29th April 11:34

[Painey]

I attended the VMax day at Bruntingthorpe earlier this year and on one run we had 164mph showing on the display board through the speedtrap at the end of the runway.

My Griff's a completely standard 500 on an N plate, currently putting out 285bhp/330lb ft which, as far as 'standard' cars go are pretty good bhp/torque figures. There are certainly more powerful "standard" cars out there so I certainly think it's possible!!!

>> Edited by Painey on Thursday 29th April 11:34

[DustyC]

beano500 said:

- mine cuts in about 6200......

Mine too

[Patrick L]

I was clocked at Brunters at 160 mph. Speedo reading was 165.

[DustyC]

What distance do you think is required to achive top speed from stand still?

[Leadfoot]

I've had just under 180 on the clock with 6k rpm showing on a French test track, so they will pull the revs in top.
You should've left the boxter for dead.......

[sw2373]

You would have thought my Griff was faster than a Boxster S...

It has been quicker off the mark than a 911GT3 RS all the way up to 120mph... but then ran out of steam and he passed me, quite quickly..

My Griff actually seems to lose it's steam quite a bit on the Autobahn's since everything as you all know has a normal speed of around 120mph over here...

Maybe mine needs looking at?

[donatien]

Leadfoot said:

I've had just under 180 on the clock with 6k rpm showing on a French test track, so they will pull the revs in top. You should've left the boxter for dead.......

Yes, they will pull to limit in top given time but at say 6k or 6.2k revs you will have substantially less power than at peak around 5.5k - guessing 280ish peak 230ish @ 6k for a standard 500.

My point was that if the car was geared a wee bit longer 170 or even 175 could then be arranged to coincide with peak power. You'd lose a little bit of acceleration of course.

Mine reads about 80mph @ 3k revs. That *should* give 160 @ 6k assuming everything is normal and increments are linear. Maybe the speedo gets a bit lost higher up? Most I've seen on mine was just over 150 at a shade under 5.5k which should have read 145 or so based on the readings at 3k revs. Even so, at that point it hadn't given up urgency and would have gone further.

Agree boxster should have been dust.

[DustyC]

If the revs keep going up athen it doesnt matter that the power is going down.

Faster revs = faster wheel revolutions = more speed

[bensandars]

TVR do not fit Speedo's instead they have egometers but that just fine as are their bhp figures which are not facts but fiction, but who cares as the cars are bl**dy fast and great fun.

[neilmac]

bensandars said:

TVR do not fit Speedo's instead they have egometers but that just fine as are their bhp figures which are not facts but fiction, but who cares as the cars are bl**dy fast and great fun.

Here Here

[K67 KRB]

neilmac said:

bensandars said: TVR do not fit Speedo's instead they have egometers but that just fine as are their bhp figures which are not facts but fiction, but who cares as the cars are bl**dy fast and great fun. Here Here

Agreed!! And they have more character in there front wheels than some poxy Porker
I've never seen a Porker Boxter S turn heads, except when the tosser driving it has the radio on full blast.

[Leadfoot]

donatien said:

Mine reads about 80mph @ 3k revs. That *should* give 160 @ 6k assuming everything is normal and increments are linear.

Not quite how mine works out:



Dunno about your idea of gearing for 170/175 - would it still pull that gearing, I dunno as the last bit from 160 to 180 (on the speedo) takes a fair old while.

[zz top]

Clocked by police speed camera at 145mph [roof down] when the speedo reading was just under 160mph. This was a TVR organised speed event over 2/3rds of a mile with a 1/3rd mile stopping distance [before we hit the end of the runway] at RNAS Culdrose ,Cornwall. Just goes to show how much the speedo can be "out"...zz

[H & the Tsunami]

minor variations in tyre size between manufacturers could effect the true reading at that sort of speed.
I have had my Griff for 3 weeks now and I've seen 145mph on my speedo so far (Shhhh...it wasn't on a track and that corner appeared b****y quick) gotta do a track day soon.
I noted that my 94 Griff500 black dial only goes upto 160mph!? must be a mistake better get it checked out by TVR...lol

[Toffer]

The Grif mid-range acceleration IS awesome though...

If you drive a well-maintained Grif you should be able to keep up with most traffic?