Who what? Right click grit your teeth and blink and eye, stand on one leg, and what is this about pexed you have me curious and confused?? Please explain or email me. Z-Force yes we are looking long term and good input. Also mikec(nz) some common sense approach and feed back and yes apples for apples is the only way and back to back to back testing as heat soak effects results too. By the way have you ever taken your car to the drags? Yes the guys from SZ appear to know what they are doing as far as results at the drags, and nothing against them it is more the info provided about them that was odd that got me. The split dump pipes whoever makes them they are clearly nice and next question is do they fit right hand drive cars with steering column difference, or are they another left hand drive product that does not fit or requires mods?
The old SZ split dumps fit the RHD cars, not sure about the expansion chamber ones. Yeah John have taken both cars to the drags, but had a lot of traction problems, both ran similar times low 13's at about 160kmph. Would have to make some suspension mods to get the power down and did not want to on the race car as it is set up for circuit racing. The street car has been retired from motorsports as I use it daily and don't want to break it!!
Gold Now I remember and understand as this stumped me being semi old school with computer stuff, thanks for the explain. Mikec(nz) Traction problems understatement. Your mile an hour is not very high either though, and must have had rock hard tyres or dyno figures are different scale to ours? Mine is circuit car also and at the time had very hard suspension, but we do change rear wheels to 15's and DOT drag tyres which helps a lot. The only test is back to back on same car on dyno, I would be surprised if even on my big hp car it made more than 10rkww more. With ROB 260's engine with bigger turbo's, which is the type of car we made them for is a better test to show difference as bigger exhaust wheel again.
Bellmouth VS Splitflange Dumps Sizes Compared Was over at the shop today dropping off more parts and getting more happy snaps etc so we measured up an X-Force 3" splitflange dump against one of the 3" Bellmouth dump pipes going onto my car. Thought I would put the pics and info into a nice concise post. Results will be interesting to some, and others I'm sure will be upset because it is an X-Force dump pipe not one made in the US haha First up, meet the bellmouth dump pipe The first comparisson involved shooting a picture through the exhaust housing from a GT2871 RS turbo with the dump pipe fitted behind. Note in the pics below the exhaust ports in the turbo and dump pipe line up perfectly. No rough edges or reduction in surface area. And a quick side on to show no funny business Now for the numbers.... Obviously not being perfectly round openings (see top pic) it is hard to get an exact measurment. To be fair, we took measurments with vernier calipers at the largest and smallest points either side of the divider as per pic below. Exhaust: 53mm and 48mm Wastegate: 68mm and 42mm And the challenger, X-Force Split Flange Dump Pipe So test number one, shooting through the exhaust housing of the same GT2871RS turbo. In this instance we see that there is a fair chunk of dump pipe obscuring the exhaust port. This would cause significant reduction to flow as the exhaust gasses hit the edge of the pipe and have to move through a small hole... And the side on pic showing that yes this is indeed the X-Force pipe Once again the two sections of the dump pipe were measured with vernier calipers Obviously being perfectly round only the diameter was required. Exhaust: 47mm Wastegate: 34mm stepping down to 32mm So there you go... Hope this was an interesting and informative read. More of an academic excercise than anything else as the X-Force dump pipe used is for an S14 NOT THAT IT MAKES ANY DIFFERENCE TO THE SIZE OF THE HOLES but obviously there is no hope of fitting to a Zed and dyno testing. Would also like to add at this point that there would be no hope of enlarging the holes on the splitflange design without causing the gasket to leak. I'm hoping to add another instalment when we are able to Dyno test.
Not a lot difference really, both pipes need a little work. Also the xforce pipe is 1/16 the cost off the uas pipe ($1650 in mild steel) which is on the left in the pic. The uas pipe in the pic above is S/S, I won't bother asking the price, because the mild steel version is out off my price range, and just about every one else's imo.
I can't beleive I have read through 6 pages of this and there are still no dyno sheets to prove the selling point. I can remember being asked by UAS to make them after seeing the ones on the DriftZ. We were asked to make a divorced type that consisted of 2 different sized mandrels sliced along their entire length and blended together and tig welded as these were the best. We then offered a split type, as well as the cheaper Bellmouth type as the labour would be a lot less. John asked us to make all three types on the car and dyno test each one, and whichever one came out best, we would then have to jig them and make them exclusive for UAS. The customer would then pay a token fee for using his car for the development work. I told him we would need the car for around 3 days, and when I asked him whether he was going to pay for all of the testing, fabrication and jigs, nothing eventuated. I can see that even though John has his own dyno, and 18 months has passed, he still hasn't tested the different types of dump pipes on a 300zx. The ones on the DriftZ were 3" main pipes and an 1-3/4" waste gate pipe that joined in around 18" away from the turbos and they were long pipes that went around the starter - similar to your new design. We haven't done any testing either, but I can't see how a bellmouth (with or without a seperator) would be better than a 3" main pipe with an 1-3/4" waste gate pipe that joins a long way down the dump pipe. A Bellmouth with divider is only big for the first 3" of length and the divider for the waste gate gas takes up more than half of this area, so you are virtually left with a 2" - 2.25" pipe for the exhaust gas leading into 3". How can this be an expansion type??? The split pulse dump pipe has 3" pipe for the exhaust gas and 1-3/4" pipe for the waste gate gas, which leaves a lot more room for unimpeded gas flow. From memory the exhaust wheel is less than 2" diameter. Maybe I, like many others are wrong. But it looks like no-one will ever know for sure, because no-one is prepared to spend the hours doing the testing for others to benefit by the results. Most people that have posted are just after a dyno sheet, and that is what prompted me to read the whole 6 pages (having history on the subject). Cheers Greg
I can't believe you have read through six pages and are still bringing up dyno testing???? As mentioned above yes there will be testing done against the SZ expansion pipes but as nobody has any yet it's a bit hard.... There is a batch on order at the moment and I have someone who is prepared to volounteer their set and of course more info will be posted when available.
I wish i could afford the turbo's let alone the dumps What no dyno sheet??? Its not that important. So when will your car be done rob, i want to see some BIG numbers
Rob, 18 months ago I was told a different design was the best. I quoted on 3 designs with the bellmouth being the cheapest of all 3 designs. I was asked to make the 3 different styles on a car and do back to back dyno testing on the same car for them to see which one was the best and then maybe get an order for a couple sets. All 3 sets would have been 3" long style turbo to the cats - ie not testing a short dump pipe against a long type, and not 2.5" against 3". Now 18 months later, the bellmouth is the best, so I assumed there would be at least some proof, as in my opinion, the split type is the better design. Remember, this is from a workshop that specialises in 300zx (so 300zx cars are always there to make prototypes on and do testing) and they own their own dyno. Maybe they are the best design - who knows? As I said, I have not done any testing either, but I am also not pushing any barrows. I am not having a go here, but this goes against what most people believe to be true. The only way it can be true is if it has been tested against other designs such as long 3" split dumps, etc. You started the thread nearly 2 months ago, and several people have asked to see dyno sheets, any dyno sheets - who mentioned testing against the SX expansion type? I don't think this is an unreasonable request. The way I read this thread, it appears the cheapest design is now the best and no testing has been done on 300zx's, otherwise there would have been a dyno sheet produced. Maybe I am wrong. On forums, it is hard to sort the fact out from the fiction, and people who read these forums and do not know any better, take this information as gospel. Therefore, it is in the best interests of the forum members, that the info produced in here is factual (to the best of our knowledge). Even the so called experts (even me) do not know everything, and they too learn from forums. Also, as time goes on, what used to be the best is now outdated as more testing is done and new ideas are revealed. I am not having a go here, but when I read this thread, I thought the testing must have been done, and I could gain info by seeing the results. To my dismay, it is merely more propaganda and wild claims. UAS obviously did not want to pay for the expense of doing the testing that they wanted us to do for free. I remember reading a Street Machine article a few years ago on LS1 Gen 3 Commodore extractors. Sam's Performance tested 22 different sets on the engine dyno on the same engine which was stock. He then did heads and cam on the same engine and tested the same 22 sets of extractors again. All the results were published in the magazine over 2 issues and Sam's Performance got a lot of publicity and work from the articles. Sam's Performance specialise in these modern Commodore V8 engines and that is why he did this testing. I only mention this so that it may motivate others such as UAS to show some of the commitment that other Marques are getting. Cheers Greg
Another top post, informative and factual. Interesting that the cheapest design became the best design, and also the most expensive design...
Confusing Thunder I think you have the two mixed up? It is the Bell mouth that has more volume and the Bell mouth has full 3 inch from flange back and the non turbulance cannot and is smaller overall for the first few inches or more actually. A Bellmouth with divider is only big for the first 3" of length and the divider for the waste gate gas takes up more than half of this area, so you are virtually left with a 2" - 2.25" pipe for the exhaust gas leading into 3". How can this be an expansion type??? The split pulse dump pipe has 3" pipe for the exhaust gas and 1-3/4" pipe for the waste gate gas, which leaves a lot more room for unimpeded gas flow. From memory the exhaust wheel is less than 2" diameter. We have not tested on dyno back to back with split dumps on zed only on a Stagea as mentioned. Relatively quick test compared to a zed and flanges are different on my car, so not simple bolt on and off and back on they dyno. We will test when we can get to it. I thought the split was better also, and maybe for stock turbo but found not for bigger turbo's at least. Did you say testing 22 sets of extractors. Do they have a government grant or is this a typo. Did not think there could be 22 different ways of making extractors. Re costing again they are full length dump and engine pipes not just dump pipes and not easy or cheap to make in stainless, not mass produced.
Hi Greg, pls excuse where I have chopped your quotes, tried to do as few replies as possible. as John and I have mentioned earlier the information is based on testing done on a stagea. This is not new information and Power Enterprises for example (who made some of the earliest big HP turbo kits for Z32) reccomend bellmouth dumps for their turbo kits. As far as specific Z32 testing no it has not been done and nobody is pretending otherwise. As I'm sure you can appreciate swapping sets of these out etc is difficult and time consuming, John's set for example have flanges in different places etc, not a big deal for a workshop to modidy but at the end of the day it's time which could be spend on paying customer cars. Several members have made it clear throughout the thread that they would not pay the price regardless of performance so not much incentive to go about making prototypes etc... That said yes I realise some Z32 testing is warranted and as many believe the Specialtyz expansion dump pipe to be the "best" on the market we are happy to test against these when there are some available. You seem quite reasonable but I guarantee that if John went to the time and trouble of doing accurate testing against his 3" CES dump pipes people would jump up and down saying that it's not accurate info because SZ expansion pipes are supposedly better etc etc Also would point out that my most recent post was purely academic information on sizing, not a selling point and I did not suggest at any stage that it was substitute for dyno testing. Information is factual, mathematically precise and is there purely for those interested. Definately not the cheapest and if you saw them in the flesh you would understand why. Not simply a right angle bend, there are many many different segments and all hand made not mass produced. This we can agree on! I could write a book on the "must have" forum reccomended parts that we have found issues with throughout the course of my rebuild. Also you mention that information must be factual to the best of our knowledge and that has been the case throughout this thread. Are you (or other members) suggesting that UAS have plucked this info out of thing air and gone to the trouble of making these dumps (prototype made in house) on a whim? Members can choose to take it or leave it based on the information available to support, but that does not mean it is fictional. Case in point lots of people are happy to believe that splitflange are better (and this has been conventional wisdom for some years) but I have NEVER seen any testing done against large bellmouth design, only the US testing in which they prove (to nobody's surprise least of all yourself I would suspect) that bigger splitflange outperform smaller splitflange. This is confusing to me. Are you saying they were 3" pipe all the way to the exhaust housing on the turbo and then separate pipe coming of wastegate? There isn't enough room on the back of the turbo to do this.... Do you have pics? Not suggesting these are expansion or any other type and again I think you misundertand the info? It is a SINGLE 3" pipe all the way to the turbo with very thin walled divider taking up bugger all space. Also split pipes cannot have a 3" exhaust pipe there simply isn't enough room. Even the CES typw below, 3" main pipe and totally separate exhaust pipe. But where they bolt on to turbo at pic below the 3" pipe has HAD to reduce in order to fit two separate pipes at turbo flange. Hence flow impeded compared to bellmouth type. Last of all Bit of a cheap shot there mate, many many sides to your financial arrangements with UAS at that point in time and I know john tells a different story. No point bringing that kind of stuff into it. Anyway hope that clears some things up? Again I am not suggesting any of this info is substitute for back to back dyno testing, certainly not where potential buyers are concerned. That is why this is tech discussion thread only and not for sale
.....I have....... ....................a question guys Will your test comparison be done by an independent work shop, similar to the independent comparison done between the MS Manifolds and the ** AMS Z Store manifolds **, as shown in the '' For Sale by Business Section ''.?... If so it will be an excellent exercise to technically evaluate both systems in performance and pricing and availability. Well done Rob and JP:zlove:
