joolz' sprint article

[mlumb]

since the 4.2 cerb seems to produce such good power outputs in relation to the 4.5,sometimes 40-50bhp more ive had an idea.

i thought i'd get my engine downsized to a 3.9 and then gain another 40bhp, getting a bit closer to the factories claims.

in fact i could go 3.6 or 3.3 the power just keeps coming..............

a chap asked me the other day if it was a 2 litre, yeah i said, with 600bhp!!

[joospeed]

that must be the reason there's a 3.6 litre SP6 then .. can't get any more power from the 4 litre so they go smaller .. "there's no substitue for (lack of) cubic inches" as they say ..

[mudstud]

A cheap and quick way to downsize would be to disconnect one HT lead - if done successively one could find the optimum performance, then saw off unused cylinders for weight reduction...where is all this going anyway!

[mlumb]

nowhere really,i'm just glad i could only afford a 4.2.

[chrissy g]

me too!

[bilton_d]

I had great interest in Jools article in Sprint and have seen various reports about BHP figures or lack of them. If the S6 engine is so close to quoted levels yet the 4.5 is potentially so far out how come at Elvington last Year (only track day i visited) the Cerbera's, 4.2 and 4.5's appeared to be so much quicker on pick-up and top speed than the Tuscan's including the yellow Tuscan S?

[rude girl]

joospeed said: "there's no substitue for (lack of) cubic inches" as they say ..

So let's get this straight. Does that mean that size is important, or that it isn't?

Just want to be clear.....

[simond001]

Maybe this explains the 1.2 Nova's always looking for a race.

with 3000 cc less, they would embariss the best of supercars!

[B19TOY]

bilton_d said: If the S6 engine is so close to quoted levels yet the 4.5 is potentially so far out how come at Elvington last Year (only track day i visited) the Cerbera's, 4.2 and 4.5's appeared to be so much quicker on pick-up and top speed than the Tuscan's including the yellow Tuscan S?

During the spring 2002 visit to Elvington I observed that 4.5s walk past 4.2s and both can jog past the Tuscans. Joolz was ballast (a passenger) in my 4.5 at the time.

I am not a techie and perhaps the folks who know about these things can help me to understand. Presumably performance isn't all down to BHP is it? From what I read perhaps torque also has something to do with performance when the wheels are rolling on the road? In addition what about any benefit from ram air effect? Is there an appreciable ram air benefit difference between different TVR engines? If so ram air effect might not be reproduced on a rolling road?

[joospeed]

if you go on the tuscan yahoo group they're adamant that no cerbies went past their cars .. hmm .. not from where I was sat (in your car as you point out ..) big toy was MUCH faster than anything else out in it's group.
there may be some ram effect .. I'm not convinced on that score though, if you observe the sensitive barometric pressure readout on the laptop at high speeds there's no measurable repeatable increase in airbox pressure. If there is a ram effect it's very slight.
I think it's probably more to do with aero efects .. the Tuscan I suspect is a brick to the air, it might look slippery but maybe it isn't? Certainly rom the bare HP figures the Tuscan should have the legs of a cerbie, but in reality the opposite proves to be the case. Of course your car would also have been the quickest out of the previous corner ...

[pbrettle]

Driven a barely run in 4.5 and a Chimaera 450 back to back and the difference is startling... Ok, not exactly a similar comparison, but the 4.5 certainly had significantly more power than the 450 which is supposed to be 280... Drove a Tuscan 4.0 later and yes its horrendously fast, but not as fast as the 4.5.... the Cerbera is much more dramatic delivery (hate to think what the early 4.2s with the extreme cam were like). Hardly scientific, but certainly by the bumm measurement the 4.5 had the power....

Mind you - used to have a Rover 420GSI (the old square ones with the 16V TC engine). Company had several on the fleet and mine was a flier - much more power than the quoted 132 (reality was that mine was probably 132 and the rest down, but it makes a better story the other way round!). One of them was slower than a 416SLI...!!

So, Joolz' article is probably spot on in reality. Most manufacturers suffer from differing power outputs - its just the TVR fraternity check it out more than the average Rover / BMW / Vauxhall / Ford etc driver....Rather than finger-in-the-air measurements, TVRs get pukka rolling road tests... kinda highlighs what we already know.

Cheers,

Paul

[williamball]

joospeed said: if you go on the tuscan yahoo group they're adamant that no cerbies went past their cars .. hmm .. not from where I was sat (in your car as you point out ..) big toy was MUCH faster than anything else out in it's group.

And what about a humble 4.2 passing Tuscans, a Tuscan S and 4.5s. On film at www.tvrcc-scotland.co.uk (gallery)...and that very car is reluctantly now up for sale on PistonHeads plug plug plug....

WB



>> Edited by williamball on Thursday 13th February 15:02

>> Edited by williamball on Thursday 13th February 15:03

[dannylt]

Ah, well that's just the driver, and the modified suspension is worth a lot more than 50bhp!

Nice article Joolz, I guess mine is just the most powerful out there with 398 :-).

Not sure about your comment on the Speed 6 though - I thought you've only seen two runs? The Red Rose with 360 bhp, and Jon's with 373.

danny

[joospeed]

the SP6 comments were to pacify the factory who are bound to get lots of calls regarding the missing hp on customers' cars. taking jon's car as representative of all SP6 cars out there then they're all producing more power than claimed.
I don't count the red rose car of Robin .. it came late and stole the show at cheltenham. I was gutted