More power V8S
More power V8S
Author
Discussion

ukbob

Original Poster:

16,277 posts

289 months

Thursday 21st October 2004
quotequote all
Im not planning anything to do with power, except 1 hour on the RR after shagged injectors are cleaned but...

It'd be interesting to hear all the possible mods our S's could have fitted, with approximate prices, exactly what is being fitted, and how many BHP said mod might achieve.

Trumpets, carbon fibre plenum, power boost valve, supercharger, sports pipes, ECU remap - from the small to the large. Have also posted a V6 thread, since us V8S owners are in the minority.

ukbob

Original Poster:

16,277 posts

289 months

Friday 22nd October 2004
quotequote all
Harry, Peter - what mods have you had, cost, and what were the gains? Pies - what did you achieve with the trumpets. Mike, any guesses on the super charger's performance? Would a £50 power boost valve (C14PPY had one IIRC) actually do anything?

Perhaps everyone is silently considering the dixi horn as the next best move?





sotonS2

14,687 posts

262 months

Friday 22nd October 2004
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HarryW

15,836 posts

293 months

Friday 22nd October 2004
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I think what Joolz says is right, can't beat CC's PeterH went this route after fettling the 4ltr. Kevin and Emma have now done this one stage further and have the most impressive figures I have seen/heard for a 4.6 .
If sticking to the origanl size the simplest is really to improve the breathing/induction/gas flow heads/balance/lightening side along with he fuel mapping . The standard exhaust can be improved upon in-way-of the manifolds and Y piece too . The mechanical ignition could do with 3D mapping to . Not forgetting the handling braking side of the whole car .
It has often rightly been said the best upgrade is the driver . Training there can release more of the cars potential and it is transferable between cars .
If you are serious about this sort of thing then I would suggest talking it through with the likes of Tim Lamont at ACT, Mark Adams, Sean/Ray at V8D, Paul/Mike at Austec, this is a buoy they sail around every day .
Been there done that, not as much as Peter though who is now considering the blower route , as what ever you have you get used too .
Seriously considering the Cerbie route myself now but have to spend precious TVR funds on a replacement eurobox familymobile first .

Harry

HarryW

15,836 posts

293 months

Friday 22nd October 2004
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Forgot to add, re the power boost valve not sure what one is, if it is the rising rate fuel regulator then AFAIK it doesn't work on the hot wire system as fitted to the V8S/Chim/Griff. It was/is a suitable upgrade to the flaper type of injection though as fitted to the Wedge's.

Harry

WildfireS3

9,919 posts

276 months

Friday 22nd October 2004
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HarryW said:
re the power boost valve not sure what one is, if it is the rising rate fuel regulator

Harry


Yep this is what it is. I was going to install one on the S but since I have the vertical bolt type which is £40 odd more than the other type I have decided not to.

GreenV8S

30,999 posts

308 months

Friday 22nd October 2004
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The FSE type 'power boost valve' does work on the hotwire systems, but Mark Adams advises against them on the grounds that the units are mechanically less reliable and quickly lose their ability to control the fuel pressure accurately. You can achieve the same effect via the ECU fuel map anyway. In fact if you have got a fairly rich set up to start with then adding a rising rate pressure regulator to up the fuelling even further might be the wrong answer, you can have too much of a good thing.

ukbob

Original Poster:

16,277 posts

289 months

Friday 22nd October 2004
quotequote all
Would a car that is running too rich have extra power - I presume not, and that a perfectly remapped car would have the most power (only asking as Mark left me running rich on purpose, to compensate for my 2 shagged injectors)

GreenV8S

30,999 posts

308 months

Friday 22nd October 2004
quotequote all
I can't say from first hand experience so hopefully one of the experts will chip in, if we're lucky we might even get Mark Adams to give us the authoritative explanation. As I understand it there is an optimum air/fuel ratio for power which is a compromise between lots of factors; running richer than this will cost power by inhibiting oxidation of CO to CO2, which is a process which liberates a lot of energy. Hence running richer can produce less power. However, it will also change the combustion speed and lower the combustion temperatures which might allow more ignition advance without pinking, especially in a forced induction setup, so sometimes there is good reason to run richer than normal. However, there is always an optimum amount of fuel and the further you go away from this (in either direction) the less power you will get.

WildfireS3

9,919 posts

276 months

Friday 22nd October 2004
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As I understand runnging slightly rich does increase power. The down side to this is:

More fuel used
Plug fouling
Bad emissions
Bore washing promoting excess bore wear.