It's NO surprise that our turbo intake systems are restrictive when upgrading turbos... Hence why I have planned to run 3"intakes for a while now .. some would've said its overkill but proof below by ASHPEC who has tested and now selling these 2.5inch versions .. . from Ashspec ----------------------------------------------- Original prototype of turbo inlet pipes, Feb 28. 2.25" o.d., 2.12" i.d. mandrel bends used to get around manifold shields and engine mounts, expanded out to 2.5" o.d., 2.37" i.d. upstream. As large as the tubing can be to fit. 8% and 15% improvement over stock inlet pipes, 3% variation between sides. V2 inlet pipe prototypes built, March 7. Full 2.5" o.d., 2.37 i.d. mandrel bends used in conjunction with BDE engine mounts for clearance . . ------------------------------------ The results: The first two results are using the V2 full 2.5" turbo inlet pipes attached to the complete induction tract. These also have the transition plate attached which limits the cross section to 2.1" dia. The second two results are of the V2 full 2.5" turbo inlet pipes attached to the complete induction tract. These do NOT have the transition tapers and have a full cross section of 2.37" dia. #5 and #6 are the V1 inlet pipes attached to the complete induction tract. These tubes have a cross section of 2.12" at the compressor flange and open to 2.37"i.d. for the connection to the rest of the tube system. And finally, the last two are of the complete original induction tract for driver and passenger side. TOTAL Combined flow (both driver and passenger side) V2 w/transition: 796CFM V2 w/o transition: 917.3CFM V1 : 752.4CFM OEM: 584.5CFM My original goal was to reach 750CFM - that was accomplished with the V1 inlets and full 2.5" lead pipes. The V2 pipes w/transitions had an increase of only 5.8%. This directly represents the effect of the limiting 2.1" inlet at the compressor housing on the V2 inlets. There will be a gain of 5.8% in using the V2 inlets and turbos with 2.37" i.d. at their flange. It will require modified compressor housings and BDE mounts to fit them. For the vast majority of folks, the gain of 29% using the V1 pipes and complete 2.5" inlet system upstream compared to the stock plumbing is going to provide notable benefits in performance for less cost in both time and money. Referring back to the flow demands of the inlet system based on engine RPM and boost level we can see what improvements this new system will offer. The V1 pipes with full 2.5" lead will offer less than 1psi of pressure drop at 18psi of boost up to ~6500RPM - right about where torque production in our engines starts to fall on its face. This is an improvement by ~1000RPM compared to the stock inlet system. . ------------------------------- Here's a chart showing the total system flow for the various inlet configurations per pressure drop. For those trying to understand what this chart represents: What you are looking at is a representation of what kind of pressure drop you will need at the turbocharger compressor inlet to produce a given flow volume. The key is to have the lowest pressure drop - thelower the pressure drop, the easier it is for the turbocharger to produce efficient boost pressure to the engine. ----------------- And now you can use the two graphs to see what the CFM requirement is for a given boost pressure and engine RPM. For example: Look at 6000RPM and running 1.35bar of boost at the intake manifold. This will put a demand of 738.5CFM on the inlet system. Then refer back to the top chart along the Y axis for this flow volume. V2 w/2.1" i.d. flange = 0.86psi pressure drop V2 w/2.37" i.d. = 0.64psi pressure drop V1 = 0.95psi OEM = 1.57psi pressure drop (these precise numbers were pulled from the spreadsheet data, represented here only by the chart) In addition, I also flowtested JUST the V2 inlet pipes without the transition plate and got some very nice results. Driver's Side, V2 2.5" w/o transition : 529.8CFM Pass Side, V2 2.5" w/o transition: 516.1CFM TOTAL COMBINED: 1045.9CFM There is a total loss of 128.6CFM induced by the lead pipes from the filters to the turbo inlet pipe interface. Even if 3" replacements were used in these positions there will still be a reduction in flow, not as large as with the 2.5", but even it we presume it will only be half, the system will flow 981.6CFM. A 7% increase in flow, presumably. Routing 3" tubing underneath the headlamps isn't impossible, definately challenging though, and would not be a direct bolt-on affair. Modification to the unibody is guaranteed. Will continue with these efforts and see what will be required to pull this off. The goal I was shooting for of 750CFM total was achieved using the V1 inlet pipes and a full 2.5" system from the filters to the inlets. This improvement in flow should be easily seen in dyno testing, which will come soon. But for those who are going all out with their builds, we will make the V2's available and offer new turbo housing flanges to mate with them. More testing and fabbing will come to entertain using 3" lead pipes, but I think those kits will be reserved for a smaller group of owners. More to come.. Enjoy these video clips at the flowbench: http://ashspecz.com/Web Documents/TurboInletDevelopment/P3080364.AVI http://ashspecz.com/Web Documents/TurboInletDevelopment/P3080365.AVI .
Far out that is detailed testing and data. It all helps and not expensive, it may not convert to much increase in power or lag, but in theory it could. Each only feeds a 1.5 litre motor.
why did you go 2.5 inch intakes .. both OEM pipes flow 584 CFM our stock engines can flow 764CFM at only 6000rpm at 20psi
still in the process of producing these so not on website yet http://www.google.com.au/url?sa=t&s...viadlnYffZRmDbIQA&sig2=iSUsiBDSQ71GEhtGON8VRg
I've already been making these for customers in 2.5" with the full inlet available by request right under the headlamps and then to twin three inch intake pipes to the airflow meter and filters. Thanks to Ash for testing and proving what we already knew Pictures of what I have made (in development stage, PCV fittings etc all added after photos) Intake viewable under the boost pipes fitted in this car: These pipes are not that hard to make and the likes of UAS could whack them up for you no trouble at all. Alternatively I can make and supply at request, I have the materials in stock including the custom laser cut flanges I have no doubt other people have been making these at customers request for a long time as well. Will be interested to see the cost of these when released, if it works out cheaper for the customer then I could be buying from Ash :rofl:
I only made the turbo inlet pipes and had the not so enjoyable task of fitting the customer supplied boost pipe "kit" the passenger side "hot pipe" was so far wrong I had to start from scratch making my own one that actually fitted. The radiator did fit but it wasn't a nice fit, the kit came with a couple of the pipes crashed or beaten flatter around the radiator area - not ideal. What you see in the eng bay pic is the full 2.5" boost pipe kit made by someone else and then modified by me to actually fit and then the turbo inlet kit made by me. Most of the viewable pipes were later polished and things started looking pretty good
They end up costing around $400 NZ for a pair of the pipes that bolt to the turbos, the pipes that run from there to the ones under the headlamps are closer to $300 nz. A lot of the cost is in the pre bent tubes that are and welded as required, with a mandrel bender Ash should have a serious price advantage - we will see.
So all up for one of your complete 2.5 inch conversion sets you would charge just $700NZ? Thats like $500AUD... thats actually a really good price mate. I'd sign up for a set...? Especially knowing that you have dealt with all of this numerous times so fitment with a set from you should be much less of a problem. MoulaZX
Rob, to make more power and possibly less lag. Question is does it actually convert to more power. I guess it does and these flow figures given suggest it would. When we did this first about 8 years ago, it required custom engine mounts, or major cut and shut of stock ones, now with BDE nice mounts, it is much easier. Yet another pioneering thing we did on zeds. This was our motorsports kit we started about 7 years ago, with custom engine mount seen in black towards the top. First version on my car with cut and shut and Tig welded engine mount. http://www.nismo.com.au/ProjectZed/revzedeng1.jpg
I prefer to fit them to each engine as it would be a pain in the ass to have a set sent over and not fit. Talk to John, as per his post he started these seven years ago My design only needs very minor modification of the mounts and doesn't need any welding on them etc but is VERY close fit so I would need to be able to mock it up here with the exact same turbos and manifolds etc to ensure the correct fit. The price I mentioned would supply four items, the two pipes on the front of the turbos and the two that go from there to under the headlamps. Any other bits would be extra, the front pipes I made for mine would be worth ~ $400 at a guess. I really need to get a cnc mandrel pipe bender ... expensive piece of gear but massive cost savings on each job with reduced welding and fitting time etc.
