dblenk Posted April 30, 2008 Report Share Posted April 30, 2008 Hi all i am still messing around trying to research into what to do to this car of mine, now decided on this from Kas Kastners book, i spoke to the guy who wil be doing the mods, his advice is that the 40's restrict the breathing and should flog them and go for a set of new weber 45's before decking blocks, port and polishing heads and fitting a S2 cam (pheonix 6-3-1 manifold also to be fitted) Question is it that critical on the inlet bore, i cant remeber what the inlet bore is on the PI system what do you think or is it the jingle of £1500 for the webers, i can see the wifes face, big bill, little box, the car only cost 5K any pointers would be helpful regards david Quote Link to post Share on other sites
Andy Moltu Posted April 30, 2008 Report Share Posted April 30, 2008 I was under the impression that 40's were a better option - the 45's may give a greater peak power on a full race spec car but sacrifice driveability lower down on a road car. Quote Link to post Share on other sites
foster461 Posted April 30, 2008 Report Share Posted April 30, 2008 I was under the impression that 40's were a better option - the 45's may give a greater peak power on a full race spec car but sacrifice driveability lower down on a road car. Agreed. For a street car the 40mm chokes with appropriate jetting and throttle linkage should be more than adequate. It is what most TR6 Weber kits include. Stan Quote Link to post Share on other sites
Alec Pringle Posted April 30, 2008 Report Share Posted April 30, 2008 Hi David, There's a rough'n'ready correlation between choke size and cylinder capacity, as you are doubtless aware. Too many tuners think only in terms of 4-cylinder engines, as in 2 litres of 500cc/cylinder, and a pair of twin-45s - although for most road (as opposed to competition) applications 40s are more than adequate The 2.5 litre 6 has only 417cc/cylinder, almost 17% smaller in capacity. The 40s are some 21% smaller in cross-sectional area than 45s. The 2.5/6 on a trio of twin-40s isn't far behind the 2.0/4 on a pair of twin-45s in terms of flow, and a long way ahead of that same 4-banger on 40s. Conclusion - as far as the TR6 is concerned, stick with the 40s for tractability and some semblance of economy on the road, and reserve the 45 option for serious competition engines. Cheers, Alec Quote Link to post Share on other sites
Tom Fremont Posted April 30, 2008 Report Share Posted April 30, 2008 FWIW, the inlet port is 1-1/4" diameter or 31.75mm. You won't be clogging up the works with 40s, especially with 32mm chokes or larger. I did sample a Racetorations TR5 ( the one on their website ) with 45s which was perfectly tractable. It had circa 200 BHP and if memory serves it was about 2.7 liters. Quote Link to post Share on other sites
dblenk Posted May 1, 2008 Author Report Share Posted May 1, 2008 Thanks lads the wife will be pleased i dont have to buy 45's As Alex said "i am doubtless aware" thats the problem i dont know this tuning lark is new to me, i have always ran std TR's but its great trying to find out, i just dont want the budget running away i got in touch with Dellorto.co.uk and teh guy there said he would check the chokes and settings and advise also its good to have a forum like this as some TR racing firms dont even blink when they mention £5K for an engine, and when i dont know what i am getting that makes everything uncertain however i will push ahead with the set up i think is right and see what happens i will put a full report on the forum when i get it finished and what i have learned as a starter thanks again everyone regards david Quote Link to post Share on other sites
dblenk Posted May 1, 2008 Author Report Share Posted May 1, 2008 dellorto.co.uk have confirmed dellorto 40's are OK upto 200BHP as there is a point where you can lose power if the chokes and carbs are to big report with more as i get it regards david Quote Link to post Share on other sites
jellison Posted May 6, 2008 Report Share Posted May 6, 2008 Just get the 45's when you decide to race it;) Quote Link to post Share on other sites
dblenk Posted May 6, 2008 Author Report Share Posted May 6, 2008 Just get the 45's when you decide to race it;) nice exhaust and mainfold on pistonheads shame i missed it race it you say, i was pleased with the MOT cheers david Quote Link to post Share on other sites
jellison Posted May 12, 2008 Report Share Posted May 12, 2008 haha - my father used to say that - took 15+ years to get him to let me race it (have my own 4) and another 5 to put to full race! Drop the bumpers off it (they look terrible once you see the car with the off - weigh loads), fit a 3.9 CWP, a fast road cam and a Phoenix 6 into 1 and you have a Mega car. Yep the exhaust went fast! It is still on it till after the 26th May All Triumph Race then off for a super trick one and the new owner gets it (Eli). Laters Jon Quote Link to post Share on other sites
dblenk Posted May 13, 2008 Author Report Share Posted May 13, 2008 haha - my father used to say that - took 15+ years to get him to let me race it (have my own 4) and another 5 to put to full race! Drop the bumpers off it (they look terrible once you see the car with the off - weigh loads), fit a 3.9 CWP, a fast road cam and a Phoenix 6 into 1 and you have a Mega car. Yep the exhaust went fast! It is still on it till after the 26th May All Triumph Race then off for a super trick one and the new owner gets it (Eli). Laters Jon Hi Jon i'll keep the above in mind, the bumpers might drop off by themselves (only joking) cheers david Quote Link to post Share on other sites
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