slybunda Posted June 25, 2021 Report Share Posted June 25, 2021 On 23/06/2021 at 23:53, Crazy Cat Lady said: I couldn't agree more with this ^ But you pays your money and makes your choice. What i've purchased is not a cat-back, it is a complete manifold back system but using the original cat which is still in excellent condition. They have fashioned the system very similar to the original spec, but in 304 Stainless mandrel bent tubes. This is craftsmanship constructed by someone very skilled and happy in his work. It's incredible how smooth and refined the engine feels now with the Alunox system, more power, and with a quicker and perkier pick up. It is an absolute joy to drive. The sounds it does produce now are very easy on the ear but remain sporty in a reserved kind of way. It won't frighten the horses. But am still utterly staggered how well the engine responds now, like a new car, the engine must love the new system which has given it a new pair of lungs and a big heart. Worth every penny it cost IME Forgot to ask whats the diameter of the exhaust you had made it looks massive compared to stock? From the pics it looks like a 4 inch. I think a standard 190 exhaust is 2.25inch or 2.5 inch. Not sure though. Link to comment Share on other sites More sharing options...
Crazy Cat Lady Posted June 25, 2021 Author Report Share Posted June 25, 2021 10 hours ago, slybunda said: Forgot to ask whats the diameter of the exhaust you had made it looks massive compared to stock? From the pics it looks like a 4 inch. I think a standard 190 exhaust is 2.25inch or 2.5 inch. Not sure though. I think [ ...but maybe wrong here ] the OEM 190 exhaust tubing is 2.5 inch, the 140 is 2.25 inch [ but don't quote me ] The new SS tubing i have is 2.25 the same as OEM. Technically the interior maybe very slightly larger because SS tubing is thiner than mlld steel. It probably just looks bigger because it's a far brighter and lighter coloured, compared to the old rusty crusty pipe. Link to comment Share on other sites More sharing options...
slybunda Posted July 2, 2021 Report Share Posted July 2, 2021 odd, i measured the stock exhaust pipe on my 190 and its different diameters. the part that goes from the manifold into the cat is around 2.5 inch and the pipe that comes out the back of the cat and goes through to the back of the car is around 2.25 inch. shouldnt the system be a single size all the way through? Link to comment Share on other sites More sharing options...
Crazy Cat Lady Posted July 2, 2021 Author Report Share Posted July 2, 2021 5 hours ago, slybunda said: shouldnt the system be a single size all the way through? I guess not, my photo below of stock 140 system shows an obviously larger girth down pipe from manifold to cat, compared to a smaller pipe between resonator to rear silencer. Link to comment Share on other sites More sharing options...
trophytr5 Posted July 3, 2021 Report Share Posted July 3, 2021 23 hours ago, slybunda said: odd, i measured the stock exhaust pipe on my 190 and its different diameters. the part that goes from the manifold into the cat is around 2.5 inch and the pipe that comes out the back of the cat and goes through to the back of the car is around 2.25 inch. shouldnt the system be a single size all the way through? No. That was one of the problems I had when trying to get a quote for an SS exhaust. 2.5 inch in/2.25 inch out cats don't seem to be readily available. The measurements were tken from the original stock exhaust Link to comment Share on other sites More sharing options...
slybunda Posted July 3, 2021 Report Share Posted July 3, 2021 Would going 2.5 all the way from cat to backbox cause power loss then? Link to comment Share on other sites More sharing options...
Crazy Cat Lady Posted July 6, 2021 Author Report Share Posted July 6, 2021 On 03/07/2021 at 09:50, slybunda said: Would going 2.5 all the way from cat to backbox cause power loss then? I did read somewhere on internet that there is a limit of how fat a pipe should be before more noise and lower power kicks in, and there are good reasons why exhaust system pipes are the size they are. <> However, yesterday i was back at Alunox, after a discussion with them about the tail pipe tip which wasn't how i expected it to look. They were very good about it and really want their customers to be happy so without any fuss changed the tip to my liking while i waited, took less than an hour. Was a bit spoilt for choice actually, but what i have now is a big improvement IMO. This is purely a cosmetic feature and the new tail pipe tip causes no changes in performance of the system or sound. I'm still absolutely gobsmacked how much better the engine is running with this new system! Above: how it was initially, a 3" stainless steel cut off. Below, a new 3" chrome/slash; a little larger than the OEM but similar in design. Much better! Link to comment Share on other sites More sharing options...
Akuma77 Posted July 6, 2021 Report Share Posted July 6, 2021 thats a cleaner looking exhaust debs , love the tailpipe ... i found that with the new exhaust it felt much more responsive and felt like it breathed a lot better ...ive had mine on since 2014 so its fully sounds great now , the odd pop here and there but mine doesnt go pop , pop , pop it does like a louder version of a pop depending how you are with the throttle Link to comment Share on other sites More sharing options...
slybunda Posted July 6, 2021 Report Share Posted July 6, 2021 Debs how come your exhaust has so many welded joints? I would have thought they would have single pieces bent to shape. Link to comment Share on other sites More sharing options...
meirion Posted July 6, 2021 Report Share Posted July 6, 2021 19 minutes ago, slybunda said: Debs how come your exhaust has so many welded joints? I would have thought they would have single pieces bent to shape. I, personally, would not question Alunox craftsmanship. Their workshop is full of race cars and they only use the very best materials. I'm sure there is a reason. I had mine from Alunox and I'm as happy as a pig in wotsits. These guys know what they are doing 1 Link to comment Share on other sites More sharing options...
slybunda Posted July 6, 2021 Report Share Posted July 6, 2021 was just interested really as to why they used that approach. Link to comment Share on other sites More sharing options...
Crazy Cat Lady Posted July 6, 2021 Author Report Share Posted July 6, 2021 (edited) 13 hours ago, slybunda said: Debs how come your exhaust has so many welded joints? I would have thought they would have single pieces bent to shape. Sorry, i was meant to ask the service manager that question when there yesterday, but i forgot But i believe the answer is how the shorter length pieces can be far more carefully and precisely mandrel bent, it's a very exacting process that retains a near perfectly round interior shape so the gas flow rate is unaffected around corners. The joins being harmless and to inter-slot in a way that leaves a smooth join after welding. So a longer pipe with lots of bends in is far more difficult to work, and likely to go that little bit more out of shape on the corners, which will be to the detriment of the gas flow rate. In other words mandrel bent tubes can be good or bad in quality, and i guess short top quality bends that are carefully welded together will trump a mandrel bent long pipe which has poorer quality bends. Edited July 7, 2021 by Crazy Cat Lady Link to comment Share on other sites More sharing options...
Crazy Cat Lady Posted July 6, 2021 Author Report Share Posted July 6, 2021 9 hours ago, Akuma77 said: thats a cleaner looking exhaust debs , love the tailpipe ... i found that with the new exhaust it felt much more responsive and felt like it breathed a lot better ...ive had mine on since 2014 so its fully sounds great now , the odd pop here and there but mine doesnt go pop , pop , pop it does like a louder version of a pop depending how you are with the throttle There must be some strangling of the engine breathing when the OEM exhaust becomes an old and crusty age. <> I think the way they firstly fashioned the tailpipe is sort of trendy these days, but i thought it looked a bit too much like the baked bean tin without the wrapper I had a choice from the bunch below, and choose the one in the middle: 1 Link to comment Share on other sites More sharing options...
Akuma77 Posted July 7, 2021 Report Share Posted July 7, 2021 yeah i think also its where its change from a baffle system to a better gas flowing system ....thats a nice tailpipe , i can change mine anytime i want for about £65 from the place i had it done custom but at the moment i like the 4" angle type 1 Link to comment Share on other sites More sharing options...
Crazy Cat Lady Posted July 7, 2021 Author Report Share Posted July 7, 2021 16 hours ago, Akuma77 said: ....thats a nice tailpipe , i can change mine anytime i want for about £65 from the place i had it done custom but at the moment i like the 4" angle type The chrome tip on mine is held on by a clamp, they said it has some adjustment in or out, and also rotate adjust. They set it slightly offset so it contours with the angle of the Celica bumper. The big fat tail pipe tip on the left [ in the photo above ] is really for an Aston Martin Vanquish, it's a bit of a whopper, and the Vanquish has two of them! 1 Link to comment Share on other sites More sharing options...
slybunda Posted July 8, 2021 Report Share Posted July 8, 2021 On 06/07/2021 at 23:03, meirion said: I, personally, would not question Alunox craftsmanship. Id question it. Iv been doing a lot of reading up on this and seen a lot of youtube vids now and it seems to be that pipe bending is a lot harder and expensive to do since decent computer controlled mandrel benders cost over 25k and price goes up sharply from that if wanting a unit than can do 3 inch or larger pipes. Various forums and blogs i checked (yes got a lot of free time) say welded joints are areas where there can be a restriction in flow due to the weld not being smooth inside the pipe and also being failure points where corrosion can start at. Generally it seems to be that exhaust builders that dont want to outlay the cash for a cnc mandrel bender go with welding which is a cheaper option for the shop. Im surprised since a shop that does so much exhaust work hasnt invested in a proper mandrel bending machine. The sharper bends are done with machines that fill pipe with sand or real expensive ones use liquid like water called hydroforming. Interesting videos to watch on YouTube. 1 Link to comment Share on other sites More sharing options...
meirion Posted July 8, 2021 Report Share Posted July 8, 2021 1 hour ago, slybunda said: Id question it. Iv been doing a lot of reading up on this and seen a lot of youtube vids now and it seems to be that pipe bending is a lot harder and expensive to do since decent computer controlled mandrel benders cost over 25k and price goes up sharply from that if wanting a unit than can do 3 inch or larger pipes. Various forums and blogs i checked (yes got a lot of free time) say welded joints are areas where there can be a restriction in flow due to the weld not being smooth inside the pipe and also being failure points where corrosion can start at. Generally it seems to be that exhaust builders that dont want to outlay the cash for a cnc mandrel bender go with welding which is a cheaper option for the shop. Im surprised since a shop that does so much exhaust work hasnt invested in a proper mandrel bending machine. The sharper bends are done with machines that fill pipe with sand or real expensive ones use liquid like water called hydroforming. Interesting videos to watch on YouTube. Well I have zero expertise in the area of welding and fabrication. I'm happy to have had my exhaust manufactured by a company with an outstanding reputation in their field. Their workshop is rammed with race cars and high end motors. I'm sure the racing community want the best . Link to comment Share on other sites More sharing options...
Crazy Cat Lady Posted July 21, 2021 Author Report Share Posted July 21, 2021 While we were underneath the car today (fitting new rear ARB bushes & drop-links) i took a snap of how Alunox has cleaned up the original cat and neatly welded it onto the new stainless steel pipe. I think the golden colour maybe an effect of indoor lighting but makes it look a thing of exotic beauty! 2 Link to comment Share on other sites More sharing options...
Xanadu Posted July 23, 2021 Report Share Posted July 23, 2021 (edited) Next job on the list will be fitting a penny washer to the cracked/corroded heat shield. Edited July 23, 2021 by Xanadu Link to comment Share on other sites More sharing options...
bazz54 Posted July 23, 2021 Report Share Posted July 23, 2021 On 21/07/2021 at 17:59, Crazy Cat Lady said: I think the golden colour maybe an effect of indoor lighting but makes it look a thing of exotic beauty! That coloration looks more like a straw temper film due to heat, but it's not present on the sloping sides of the cat which seems odd. Why would all that pipe have a temper film; so far from the welds and I doubt if exhaust gas temps would be high enough to do that? Link to comment Share on other sites More sharing options...
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