lynchpin Posted February 5, 2019 Report Share Posted February 5, 2019 Hi All Brochure arrived from Rimmers today, I am sure you all got one, I was thinking of doing some work on the 4 soon perhaps having the head gas flowed and unleaded while its off and a better exhaust system, in their offers they have sports stainless systems with 4 branch manifold included for £550ish . 1 Are they of any great benefit to performance at all. 2 Are they really noisy to the point of being annoying when driving any distance, (I remember my mini with mk1 sprite silencer in the early 70's).. 3 Also the engine in my car originates from a 4a (engine No) don't know about the head though are they the same 4/4a do they use the same 4 branch manifold. Phil... Quote Link to post Share on other sites
harlequin Posted February 5, 2019 Report Share Posted February 5, 2019 Hi Phil Personally I didn't like the extra noise and under bonnet heat, also the 4 branch manifold restricts access to the starter motor. I changed my 3A back to a standard system a couple of months ago and have been meaning to put the big bore sports system on ebay. If you decide to go for it and if you are interested in a second hand system drop me a PM George Quote Link to post Share on other sites
Hamish Posted February 5, 2019 Report Share Posted February 5, 2019 (edited) Phil i don’t have their manifold on my 3a but I do have the rest of their system and it fits and works fine. I like the extra sound but then I don’t do very long journeys. The manifolds are all the same for the hi port 4pots. So you need the rest of the system to fit your car as the 4 and 4a are different as it runs front to back There may be a slight weight saving? there might be a very slight power improvement but you may have to re tune the carbs anyway as it might run a bit leaner. You do need to check the manifold plate thickness. It needs to be the same as the intake manifold thickness so that the clamps do up evenly on both. I have heard some are or were too thin. I believe the rimmer offerings are Phoenix systems. H ps george posted whilst I was typing. He has a good point about the starter motor. Some manifolds require the modern hi torque version. some also need a heat deflector plate to protect the dynamo as they are a bit longer than alternators. A second hand system was what I was after Edited February 5, 2019 by Hamish Added detail Quote Link to post Share on other sites
John Morrison Posted February 5, 2019 Report Share Posted February 5, 2019 Phil, not to the tune of £550, 4 branch manifold used to be claimed to be worth 4BHP tops, don't know about the sports exhaust, but Thats a lot of dosh for what you might not even notice, noise is a personal thing, I run one long silencer on my standard car cost was a minus cost, (I didn't buy the second one) and I like the sound, noticable but not intrusive. John. Quote Link to post Share on other sites
Motorsport Mickey Posted February 5, 2019 Report Share Posted February 5, 2019 Phil, As some of the others have intimated a tube exhaust will give a small increase in bhp but at the cost of increased noise and under bonnet heat. Why not go "half way house " ? Fit the cast TR4a exhaust manifold, they are quieter and have a pretty good gas flow for a cast system and control the underbonnet heat better than a tube system. Use the Tr4a 2 pipe and Y piece into a single pipe exhaust under the gearbox area with a single pipe central box and rear box to suit what noise output you want. Mick Richards Quote Link to post Share on other sites
lynchpin Posted February 5, 2019 Author Report Share Posted February 5, 2019 Hi George I find the information confusing in the brochure now I have looked closer after reading your answer, it lists the system without the manifold as for tr2-4 RF4072 with only 2 items, but the system for a 4 with the manifold RF4076 shows what looks like a different silencer, unless its at a different angle, plus with 2 completely different pieces of pipe making 4 items in total, perhaps a call to Rimmers is needed unless the forum people have the answer, watch this space as the saying goes.. Cheers Phil.. Quote Link to post Share on other sites
lynchpin Posted February 5, 2019 Author Report Share Posted February 5, 2019 (edited) Hi Mick I think already I am leaning away from the 4 branch, will look a bit further into other answers, yours included, as I said my engine came from a 4a but it has the snorkel lower breather not closed system and I assume a 4 manifold, didn't realize they were different will poke about when I have more time.. Thanks to all for now Phil.. Edited February 5, 2019 by lynchpin Quote Link to post Share on other sites
Nobbyc Posted February 6, 2019 Report Share Posted February 6, 2019 I have a 4a manifold with down pipes into a Y and then just an 1 3/4 " single straight thru silencer 18" long under rear axle. Bit of noise under acceleration but quiet when cruising Quote Link to post Share on other sites
ianc Posted February 6, 2019 Report Share Posted February 6, 2019 When, in 1962, the Comps Dept fitted the SAH 4-branch exhaust instead of the production item to the Rally TR4s , it was claimed that there was an immediate gain of 8 BHP - that's what our Hon Pres told me, and he should know! Heat shield is necessary, whether dynamo or alternator is fitted - ask Mr Revington, who cooked the first alternator which he fitted to 6VC, so then he copied the shield which had been on 4VC since 1962 (and still is there)! Ian Cornish Quote Link to post Share on other sites
ChrisR-4A Posted February 6, 2019 Report Share Posted February 6, 2019 Hi Phil, standard 4A manifold is good for mildly tuned cars. Before going to tubular I would fit K&N filters, narrow belt kit with electric fan and fully balanced engine all good with std manifold, then modify the head and then go tubular. Silencer wise, another option is a SS Cross box as used on a US spec 6 cyl, it has single inlet and twin outlet and a bit more gas flow than standard 4A unit. Nice sound too. Chris Quote Link to post Share on other sites
Andy Moltu Posted February 6, 2019 Report Share Posted February 6, 2019 Do KN filters flow more air? i was a under the impression for the same size filter they didn’t flow much much more. More effective filtration and reusable yes but not a big performance gain in terms of power. Quote Link to post Share on other sites
Fireman049 Posted February 6, 2019 Report Share Posted February 6, 2019 The previous owner of my 3A had fitted K & N air filters. Personally I think they are a load of bullshit! The after service from K & N is non-existent. I wanted a replacement dome-headed screw which they refused to supply for some unknown reason??? You're just as well fitting the SU filters from Burlen. Tom. Quote Link to post Share on other sites
harlequin Posted February 6, 2019 Report Share Posted February 6, 2019 I agree Tom I had them on the carburetors of my TR6, the car always seemed not quite right untill I changed back to the standard air box George Quote Link to post Share on other sites
John Morrison Posted February 6, 2019 Report Share Posted February 6, 2019 1 hour ago, Fireman049 said: The previous owner of my 3A had fitted K & N air filters. Personally I think they are a load of bullshit! The after service from K & N is non-existent. I wanted a replacement dome-headed screw which they refused to supply for some unknown reason??? You're just as well fitting the SU filters from Burlen. Tom. Way you go Tom! Tell it as you see it, Lovely to see you post. John. Quote Link to post Share on other sites
lynchpin Posted February 7, 2019 Author Report Share Posted February 7, 2019 Again thanks for all your replies will contemplate them all over a couple of beers with my mechanic brother, not sure how many I will need to by him to convince him he really needs another car to work on.. Cheers Phil.. Quote Link to post Share on other sites
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