Hangar 111 Posted October 19, 2016 Report Share Posted October 19, 2016 21 minutes ago, alias23 said: Personally I'm not too worried about a more characterful exhaust note (it would be nice but not my priority). To @Hangar 111 point for a number of folks the key priority is to have an exhaust which is lighter (the stock exhaust is bloody heavy), removes the awful pig snout exhaust tip, and passes track noise testing. I don't care for the valve switch or a big noise exhaust. I just want a decent track exhaust that can help me shed some weight at the back. Now we're making a niche of a niche market - how many units are we likely to sell, and what cost will the niche tolerate, to make anything on the development cycle? Dave Quote Link to comment Share on other sites More sharing options...
MartynB Posted October 19, 2016 Report Share Posted October 19, 2016 57 minutes ago, Hangar 111 said: You forgot the other specified requirements: d) lightweight, e) made of exotic materials, f) inexpensive, g) durable enough to survive 10 years of track use, h) no power loss between open & closed... I even missed off i) must trigger mating behaviour in attractive members of the favoured gender. what was I thinking? @alias23 Imran, it sounds like the 2bular track system is pitched at your requirements. Quote Link to comment Share on other sites More sharing options...
Bravo73 Posted October 19, 2016 Report Share Posted October 19, 2016 12 minutes ago, MartynB said: @alias23 Imran, it sounds like the 2bular track system is pitched at your requirements. Definitely not. They won't pass most UK noise tests. Quote Link to comment Share on other sites More sharing options...
RedViper Posted October 19, 2016 Report Share Posted October 19, 2016 52 minutes ago, alias23 said: I just want a decent track exhaust that can help me shed some weight at the back. 2bular track (-5kg). add ons if you need to get the db down to around 98/99db. 5 hours ago, Hangar 111 said: It's just the nearest cardboard box they had of the right size to put a silencer in - we all re-use packaging where possible to help offset the CO2 that comes out of the exhausts Great line 1 Quote Link to comment Share on other sites More sharing options...
MartynB Posted October 19, 2016 Report Share Posted October 19, 2016 Yeah sorry Jonny, I was thinking with the trackday add ons, which still keep the weight well below stock. Jim quotes "approx 98dB" with these attached which tallies with Chris' 98/99dB. Bedford is 101dB static Brands is 102dB or 105dB Indy and 101dB GP (some crazy 98dB days do exist, apparently) Pretty much everywhere else is 105dB If I've got my info wrong somewhere, do let me know. Ta Quote Link to comment Share on other sites More sharing options...
Bravo73 Posted October 19, 2016 Report Share Posted October 19, 2016 Apart from the 'prototype' set, how many other sets of the trackday addons have been seen, eh? Quote Link to comment Share on other sites More sharing options...
alias23 Posted October 19, 2016 Report Share Posted October 19, 2016 Correct that the 2Bular track exhaust isn't as track 'friendly' as marketed. I know from two individuals who have got the track setup that with the exhaust add-ons (one with the Jim setup the other a different type of add-on) not only is it a ball ache to fit them but they still can struggle to meet track day noise limits at tracks such as Donington. It is very odd as my understanding of previous 2bular systems was that they could be made to be very track friendly on the S2 model. Unsure why it seems so difficult on the V6 model. Quote www.alias23.com Link to comment Share on other sites More sharing options...
alias23 Posted October 19, 2016 Report Share Posted October 19, 2016 2 hours ago, Hangar 111 said: Now we're making a niche of a niche market - how many units are we likely to sell, and what cost will the niche tolerate, to make anything on the development cycle? Im not too sure... Don't get me wrong I completely understand where you're coming from niche of a niche, however I am seeing an increasing number of V6s on track and many more people upgrading to aftermarket parts. Track day noise limits are only going to get worse. £1-1.2k for an exhaust back box is not small change... We don't need crazy development as found with an Akrapovič as I agree that just prices everything out of the water, equally I can't see Jim doing extensive testing and R&D either but his systems are generally quite good. So why can't someone with a good degree of knowledge in this area create a suitable option for the track day community? Quote www.alias23.com Link to comment Share on other sites More sharing options...
MartynB Posted October 19, 2016 Report Share Posted October 19, 2016 Fair point Jonny. I wonder if that's partly because there aren't many 2bular track systems shipped at all. Imran, I guess the problem is that when you are trying to muffle 350 bhp worth of noise while allowing 350 bhp worth of gas flow in much the same space as you had for 250 bhp worth on the S2, while keeping weight, cost and development effort reasonable, you run into issues. So yes, I see your point about there not being much on the market that hits the sweet spot. Quote Link to comment Share on other sites More sharing options...
Seriouslylotus Posted October 19, 2016 Report Share Posted October 19, 2016 2 hours ago, alias23 said: Im not too sure... Don't get me wrong I completely understand where you're coming from niche of a niche, however I am seeing an increasing number of V6s on track and many more people upgrading to aftermarket parts. Track day noise limits are only going to get worse. £1-1.2k for an exhaust back box is not small change... We don't need crazy development as found with an Akrapovič as I agree that just prices everything out of the water, equally I can't see Jim doing extensive testing and R&D either but his systems are generally quite good. So why can't someone with a good degree of knowledge in this area create a suitable option for the track day community? That is exactly what I am doing. I want a silencer to meet track limits with pops bangs and exhaust note all being secondary Quote Link to comment Share on other sites More sharing options...
Rancid Posted October 19, 2016 Report Share Posted October 19, 2016 I'd have been happy with the standard exhaust if it weren't for the bloody awful snout. Surely someone, somewhere, would be able to change just the tips for the nicer twin set up. 1 Quote '....it makes every other roadster look just a little bit cissy...' Link to comment Share on other sites More sharing options...
Crouchy Posted October 19, 2016 Report Share Posted October 19, 2016 Ive never really understood why the above isn't possible. Obviously I have no idea about exhaust design but the valve open position would produce a true straight through sound but with the valve closed it should pass through the over sized silencer and therefore make it "track safe". You would need to wire in a switch for the valve rather than the vacuum line. The major down side I can see for a manufacturer is that it would also require a new diffuser which would bump up the price. Quote Link to comment Share on other sites More sharing options...
NANO Posted October 20, 2016 Report Share Posted October 20, 2016 12 hours ago, Rancid said: I'd have been happy with the standard exhaust if it weren't for the bloody awful snout. Surely someone, somewhere, would be able to change just the tips for the nicer twin set up. One idea: paint with the matte black the final (with a special heat-resistant paint) Quote Link to comment Share on other sites More sharing options...
RedViper Posted October 20, 2016 Report Share Posted October 20, 2016 (edited) 13 hours ago, Crouchy said: Ive never really understood why the above isn't possible. Obviously I have no idea about exhaust design but the valve open position would produce a true straight through sound but with the valve closed it should pass through the over sized silencer and therefore make it "track safe". You would need to wire in a switch for the valve rather than the vacuum line. The major down side I can see for a manufacturer is that it would also require a new diffuser which would bump up the price. I believe the problem with such a system is the exhaust valves generally aren't brilliant. in almost all cases the valve is open at max revs (and max heat). keeping it closed at max revs means the valves don't last long. Plus the people who make the valves aren't to keen on selling them to other exhaust manufacturers so it limits options. if the above existed I would have it as I like a loud exhaust for road. the nearest thing to this at the minute is 2bular track and add ons. Once you buy a spring puller from ebay the job literally takes 5 minutes to swap them over. Edited October 20, 2016 by RedViper Quote Link to comment Share on other sites More sharing options...
French Frie Posted October 20, 2016 Report Share Posted October 20, 2016 on some hardcore classic 911s, the valve problem was eliminated by just a cover on the exit(s) you didn't want to use ... one is muffled ,the other is direct ! 1 Quote Link to comment Share on other sites More sharing options...
RedViper Posted October 21, 2016 Report Share Posted October 21, 2016 20 hours ago, French Frie said: on some hardcore classic 911s, the valve problem was eliminated by just a cover on the exit(s) you didn't want to use ... one is muffled ,the other is direct ! I think you should have added a subtitle to this saying "Don't Try This At Home" Quote Link to comment Share on other sites More sharing options...
French Frie Posted October 21, 2016 Report Share Posted October 21, 2016 Quote Link to comment Share on other sites More sharing options...
alias23 Posted October 22, 2016 Report Share Posted October 22, 2016 Is this correct? @Hangar 111 did you manage to test the db at full revs with the valve closed and are you certain of no back pressure concerns say on a full day on track with valve closed? http://www.hangar111.com/lotus/v6-exhaust-noise-overridden/ Quote www.alias23.com Link to comment Share on other sites More sharing options...
Hangar 111 Posted October 24, 2016 Report Share Posted October 24, 2016 On 22/10/2016 at 10:44, alias23 said: Is this correct? @Hangar 111 did you manage to test the db at full revs with the valve closed and are you certain of no back pressure concerns say on a full day on track with valve closed? http://www.hangar111.com/lotus/v6-exhaust-noise-overridden/ KT developed the exhaust on the dyno, and it delivered the same power with valve open or closed. It is less restrictive than the OEM system. Dave Quote Link to comment Share on other sites More sharing options...
French Frie Posted October 25, 2016 Report Share Posted October 25, 2016 On 19/10/2016 at 09:52, Hangar 111 said: The exhaust uses a Capristo exhaust valve as they are of a high quality (as used on lots of high-end exhuasts). Dave I just received the exhaust I bought from @Chrisc (thanks Chris !), and I can confirm the Valve is a Capristo one ... the rest of the exhaust is marked Komo-Tec everywhere, and seems to be very well made ! carbon tips weren't my first choice, but it looks cool in the flesh. Can't wait to fit it to my car ... @Hangar 111: Dave, is there any High temp grease (copper ? ) to put on the valve mechanism to keep it away from moisture ? Quote Link to comment Share on other sites More sharing options...
Chrisc Posted October 25, 2016 Report Share Posted October 25, 2016 Glad you got it ok Enjoy the sound! Remeber leave the hose off (plug it) for a better sound Quote Link to comment Share on other sites More sharing options...
French Frie Posted October 25, 2016 Report Share Posted October 25, 2016 yep, everything was fine Chris ... even if the lorry guy achieved to deliver the pallet ... upside down ! no damage though... But I'll keep the valve functional, and will try to put a remote control (as said in an other thread) to control it (and over-ride the ECU controlled solenoid) ! Quote Link to comment Share on other sites More sharing options...
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