LostKiwi Posted June 25, 2007 Report Share Posted June 25, 2007 Ok, since upgrading the stock exhaust I've started looking into V8 exhaust tuning in more detail.... so a couple of questions for all of you with custom exhausts.... 1. Does anyone not run a balance pipe? 2. Does anyone use an 'X' pipe (as opposed to a simple balance or 'H' pipe). 3. Finally, how does it all sound? I'm getting an X-Pipe made up for mine this weekend to see if the claims of an additional 10kw more power are true (bearing in mind the tests in the article were done on a 135kW V8 as opposed to our 220kW normally aspirated V8s). It'll be a seat of the pants test unfortunately as there is no way I can get any Dyno time before or after but if any one else has tried it I'd be interested to know. There is a very interesting article here which gives some good information about the X-pipe and this is what we are going to try to replicate. Again the fabrication work will be done by Westgate Exhausts in Morecambe (starting to build a good rapport with them now!) One thing that is apparent from searching the web is that the X-pipe will definitely change the sound - much smoother and will probably make the 8 'howl' rather than thrum all through the rev range... Got to admit its a sound I rather like!!!! Interesting times ahead..... Link to comment Share on other sites More sharing options...
NickGUK Posted June 25, 2007 Report Share Posted June 25, 2007 Check this message,also includes a sound file in my post and you can hear how good the custom exhaust sounds Exhausts Link to comment Share on other sites More sharing options...
LostKiwi Posted June 26, 2007 Author Report Share Posted June 26, 2007 That does sound sweet!! So is that using a balance pipe? (from the sound of it I'd almost guarantee it) or is it an x-pipe? I'm really curious about the X-pipe.... it seems to offer more power thsn a balance pipe (sometimes called an H-pipe) and smooths the pulses more. I guess I'll find out on Saturday!!! I am curious to see if anyone else had done one already... Once I get mine done I'll see if I can record a sound bite (any excuse to make a bit of noise ). Link to comment Share on other sites More sharing options...
Tobes49 Posted June 26, 2007 Report Share Posted June 26, 2007 Botangs Quad exhaust with X pipe More pictures Here Link to comment Share on other sites More sharing options...
Botang Posted June 26, 2007 Report Share Posted June 26, 2007 Blimey I didnt even need to post Yep as Tobes and Nick have mentioned my car does indeed have and X Pipe, so does A8 Tony's. Link to comment Share on other sites More sharing options...
Botang Posted June 26, 2007 Report Share Posted June 26, 2007 It was all started by a guy called Dr Gas He designed a system for Bobby Labonte which was used on his Nascar to great effect, none of the other teams could work out what they were doing, they could hear the note was different and that he was faster but couldnt work out what was different to the rest of the cars. The other teams only found out when Bobby Labonte crashed his car and a photographer got a picture of the underside of the car as it rolled. Link to comment Share on other sites More sharing options...
NickGUK Posted June 26, 2007 Report Share Posted June 26, 2007 Botang, Where actually did you have this done ? Was it in Holland or ? Link to comment Share on other sites More sharing options...
Botang Posted June 26, 2007 Report Share Posted June 26, 2007 Yep EPS in Hoogezand Holland EPS Webpage Click on Rondleiding for the gallery and flick through the pics, its a fab place Link to comment Share on other sites More sharing options...
LostKiwi Posted June 27, 2007 Author Report Share Posted June 27, 2007 Cheers for that guys! Link to comment Share on other sites More sharing options...
LostKiwi Posted June 30, 2007 Author Report Share Posted June 30, 2007 X-Pipe now done and what an improvement... quieter, smoother and with a drop dead gorgeous sound too.... Significantly different to Botangs having a much larger and shaped crossover area... This is a design I found on an Aussie webpage where they tested it on the dyno on a Holden (Vauxhall) Monaro and it gave some very useful power gains. I've attached a picture. Link to comment Share on other sites More sharing options...
LostKiwi Posted June 30, 2007 Author Report Share Posted June 30, 2007 Another pic Link to comment Share on other sites More sharing options...
LostKiwi Posted June 30, 2007 Author Report Share Posted June 30, 2007 Last one. Link to comment Share on other sites More sharing options...
NickGUK Posted June 30, 2007 Report Share Posted June 30, 2007 Cost?, and wheres the sound file so we can hear it Link to comment Share on other sites More sharing options...
LostKiwi Posted June 30, 2007 Author Report Share Posted June 30, 2007 Cost for the original system was £590 all in. Then we found out about the X-Pipes and that was an extra £70 as a retrofit... I would imagine if ithad all been done at the same time it would have been about £630 all in. It took him 2 hours just to do the X-Pipes themselves!!!. The area where the pipes meet has a 1" section missing along the join allowing the gasses to mix and give improved scavenging. I'll do a sound bite as soon as I find something to record it on!!! Link to comment Share on other sites More sharing options...
Figure11 Posted June 30, 2007 Report Share Posted June 30, 2007 [ QUOTE ] Cost for the original system was £590 all in. Then we found out about the X-Pipes and that was an extra £70 as a retrofit... I would imagine if ithad all been done at the same time it would have been about £630 all in. It took him 2 hours just to do the X-Pipes themselves!!!. The area where the pipes meet has a 1" section missing along the join allowing the gasses to mix and give improved scavenging. I'll do a sound bite as soon as I find something to record it on!!! [/ QUOTE ] Where did you get that done and could they do a quad pipe setup with that X pipe do you think? Mike Link to comment Share on other sites More sharing options...
LostKiwi Posted June 30, 2007 Author Report Share Posted June 30, 2007 The work was done by Westgate Exhausts (and tyres and bumpers )in Morecambe, Lancashire. I don't know how they'd get on doing a quad as it is really tight.... Still, if you were to show him the pictures of Botangs he may find a way. It would certainly cost more for a quad. As for the X-Pipe - that can be fitted to any V8 in place of the balance pipe, providing there is sufficient room before the first box and nothing to get in the way of the joined area (for an A8 thats not too much of an issue).... Just been out again... I just love the V8 'howl' it has at high revs now!!! Link to comment Share on other sites More sharing options...
grdunn123 Posted June 30, 2007 Report Share Posted June 30, 2007 Are the tailpipes bigger than standard? Link to comment Share on other sites More sharing options...
LostKiwi Posted June 30, 2007 Author Report Share Posted June 30, 2007 The whole system is modular so you choose the bits you want. The tail pipes I chose (you choose whatever you like - there are a vast number of options) are oversize externally but have internal silencing in them to prevent droning and reduce noise - I wanted it reasonably quiet - so the internal dimension is about the same as standard. Externally the tailpipes are about 3.5" OD and 2.25" ID.... I've attached a picture of the back of the car to get a better idea (sorry about the quality but its persisting it down!) And yes... I do need to widen my driveway!!! Link to comment Share on other sites More sharing options...
cruiser647 Posted July 2, 2007 Report Share Posted July 2, 2007 For what it is worth, the original Audi V8 Quattro (3.6l) from 1989 era had as standard, a Cross Pipe! It was also before the Cats.......... Here is a pic from EKTA..... Link to comment Share on other sites More sharing options...
LostKiwi Posted July 2, 2007 Author Report Share Posted July 2, 2007 Interesting! That lower system is very interesting indeed as it looks to be designed to reduce the uneven firing of a V8 by ducting the gasses from one side to the other, thus balancing the firing pulses. There are only 2 ways to do that - 1 is to use a planar crank (where all the conrod journals lie in the same plane ala Ferrari and F1) or 2 is to use a cross engine manifold. The basic problem is that the firing order of a V8 gives a firing sequence like LRRLRLLR. Its the double pulses from the same bank that give the distinctive V8 note. Those same pulses though, also cause an amount of roughness which X-Pipes and Balance pipes try to overcome to more or lesser extents. The Planar crank gives even pulses from each side but has the drawback of creating a lot of second order vibrations, giving overall 4 times the vibrations of a normal 2 plane (or cruciform) crank. Cross engine manifolds are very rare due to the problems inherent in running pipes under the engine, space and heat build up in particular. Quite surprising Audi actually felt it necessary to do that on a production car! Link to comment Share on other sites More sharing options...
Figure11 Posted August 31, 2007 Report Share Posted August 31, 2007 LostKiwi, Found someone to do this for me. Do you have a design spec for the X over box or a drawing with dimensions please? Mike Link to comment Share on other sites More sharing options...
LostKiwi Posted August 31, 2007 Author Report Share Posted August 31, 2007 This is what I worked from Here Link to comment Share on other sites More sharing options...
Figure11 Posted September 1, 2007 Report Share Posted September 1, 2007 LostKiwi, Thanks for that. I take it the internals of the box look something like this... Is the gap from the input pipes 10" as suggested in the article or did you chose another dimension? Mike Link to comment Share on other sites More sharing options...
LostKiwi Posted September 1, 2007 Author Report Share Posted September 1, 2007 Mine is 10" from the point where the pipes join to the point they separate. The sound of the car is very smooth as a result. There is very little of the hard throb normally associated with a V8 but more of an almost 6 cylinder howl with a V8 overlay. The shorther the centre section the more throb remains and the less it howls, but it would seem from the article that the more the power gains move higher in the rev range (not that I noticed that much difference other than in the midrange where this is better than the previous set up). So far everyone who has heard it has loved the sound (including my mate with 350 chev powered Cobra replica). The best way to describe it is 'Muted Aussie touring car' if that helps. Link to comment Share on other sites More sharing options...
Figure11 Posted September 1, 2007 Report Share Posted September 1, 2007 Cheers m80. Mike Link to comment Share on other sites More sharing options...
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