Tony D Posted August 6, 2013 Share Posted August 6, 2013 (edited) Sound like some mismatches exist in your setup. In higher horsepower cars an intentionall plenum over sizing can mitigate jumpiness basing in favor of design compromises higher in the rpm range. I think the root of your lack of perceived tip-in issue roots in running a slush box with a high-stall converter...effectively masking any throttle input at low speed short of half. Throttle to get the converter to flash and start the car moving. Your setup is for drag racing by the looks of it, not really a finesse driving through the cones sorta car where tip-in would be more critical. Stop and go driving can be tedious with a clutch and jumpy throttle response. I'm having an issue now with what exactly your point in the thread is now--are you looking to fix something, understand what mismatches exist in your setup that make it unresponsive, or are just being a smart arse for no particular reason to than you have idle time. Please clarify... Edited August 6, 2013 by Tony D Quote Link to comment Share on other sites More sharing options...
madkaw Posted August 6, 2013 Author Share Posted August 6, 2013 http://www.ebay.com/itm/2002-2004-Ford-Mustang-V6-3-8-3-9-OEM-Stock-60-mm-Throttle-Body-w-TPS-Sensor-/230777068197 This looks like a great candidate. Genuine OEM with sensor Quote Link to comment Share on other sites More sharing options...
roger280zx Posted August 6, 2013 Share Posted August 6, 2013 I seriously don't know what tip in is. I'm guessing it's a side effect of a large tb? You are drag racing, and you have an auto trans. The tip in is not as pronounced with an auto, and you'll never notice it drag racing. I have a 60mm from a 240sx, the TWM 60mm with a larger tapered inlet, and a 65mm from a mustang. I really like the twm, there is no spacer required, and the turbo likes it as well. I never tried the sx unit on the turbo, but there was a huge change in "seat of the pants" acceleration and with a little afm tuning I felt like it ran better every where in my stock long block zx. If I get the LD28 intake I want, I will mount the mustang unit facing the valve cover with a cam and cable set up. For now the TWM wins in my garage. Quote Link to comment Share on other sites More sharing options...
roger280zx Posted August 6, 2013 Share Posted August 6, 2013 Oops, just noticed Tony D already said everything I did. And more eloquently as usual. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted August 6, 2013 Share Posted August 6, 2013 The intake I built from steel exhaust tubing was just an experiment for fun. I made it work and it seemed to work well. I had a 70mm throttle body from a 3liter alfa romeo lying in the shop so I tried it. As for stall converters, they are v8 converters so they don't stall very high behind the L6. I've tried 2k, 3k, and 4k converters and the car feels quicker with the 4k. I don't have any dyno numbers out even track times to prove anything. The last time my car was daily driven it had the custom intake and 3k converter and it was a great daily car. I really appreciate your input Tony, I've learned a lot from you. Quote Link to comment Share on other sites More sharing options...
Tony D Posted August 6, 2013 Share Posted August 6, 2013 Any autobox just won't have the tip-in issues that a standard shift car will. The Expedition / Explorer example I gave obviously has a slush box as well, it's the perceived response that the larger body gives. On a heavier car with an automatic, a larger TB will make the car "feel" more responsive...or less like a dog off the line. Quote Link to comment Share on other sites More sharing options...
madkaw Posted November 17, 2013 Author Share Posted November 17, 2013 Well I have pretty much decided on a 60mm TB off of a 5.0 mustang - mid nineties model I believe. Why- cheap and available that met my size requirements plus pwm idle control and TPS. Also hundreds of upgrade and aftermarket support is available. The TB is pretty simple with only one vacuum line coming off the actual TB itself which can be easily plugged. This should leave a fairly uncluttered looking set up. The idle control unit is long and kind of big, but I am hoping I will be able to mount the TB in such a way to put it down below - out of sight. I will need to make a mounting plate but have some 3/4" 6061 plate laying around from an aircraft bulkhead. Injectors from the same induction system work out well to- 19lb /14mm injectors . Also have decided to NOT use cable linkage and make rod linkage work using the Cannon mounting points. It should be easy to modify the Mustang TB linkage to attach rod ball. Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted November 17, 2013 Share Posted November 17, 2013 (edited) My stock L28et (other than flat top pistons from n/a) in front of a stock 280zx turbo 3n71b will break the tires loose for a couple of feet if I simply stamp the throttle at a light if the surface is less than perfect (dry, not wet). This is in a infiniti m30 with 3.54 r200 which is a bit heavier than a z car. It's possible the m30 management system helps and I'm sure the higher compression helps at tip in. What were the results of the compression test? Edited November 17, 2013 by HowlerMonkey Quote Link to comment Share on other sites More sharing options...
madkaw Posted November 13, 2014 Author Share Posted November 13, 2014 Well since my engine is in the black hole of the machine shop, I thought I would bang out some frustration on my intake plenum. Made some progress, but I think I need to get serious about measuring volume to see where I am at. It seems big and I'm not sure how to math this out with the taper. Any suggestions on some equations or methods of measuring volume on this type shape. Quote Link to comment Share on other sites More sharing options...
madkaw Posted November 13, 2014 Author Share Posted November 13, 2014 more pics Quote Link to comment Share on other sites More sharing options...
madkaw Posted December 4, 2014 Author Share Posted December 4, 2014 Had a fun day relieving stress on some aluminum. I might not be very good at it, but I sure enjoy it. Still trying to decide which route on the TB. I have a Ford Mustang(86) 60mm TB laying there, but it has that huge idle air control gadget hanging off the end that I'm not sure I will need. I'm quite sure if I make a mounting plate based on that bolt pattern I could find something to satisfy me. Orrr... buy a cheapy Chinese crafted TB that only has the TPS and comes with a predrilled and pretty weldable mounting plate. Quote Link to comment Share on other sites More sharing options...
madkaw Posted December 10, 2014 Author Share Posted December 10, 2014 How about any thoughts on the runner ID on the intake being 38mm at the head. Since I didn't design this I am curious of what the the original builder had in mind . I've read that 35mm is plenty big for stock valves, so maybe this was being set up for way oversized valves. The ports are nicely tapered all the way to the manifold. Could the head ports be matched up with this intake and be tapered down to the combustion chamber as to NOT kill velocity and use stock valves. Quote Link to comment Share on other sites More sharing options...
madkaw Posted January 26, 2015 Author Share Posted January 26, 2015 Still looking for thoughts on the runner taper on this intake. Looks like 45mm at the bellmouths tapered down around 37mm at the head side of the runnners-which of course is 2mm bigger then stock port opening. I only guess that the original owner of this intake intended on opening up the head ports and tapering them also to make this transition? Looks like the taper is about 1.3 ratio which I have read is ideal for a taper. So based on this, tapering the head port would put it back to around 35mm just before the port turns. I been trying to read up on runner length and tuning and the formulas always seem to go beyound my comprehension-which isn't much-lol. Trying to determine if this intake design is better used for a lower rpm power or the opposite. The Canon runner is only 6" long, and with no air horns, seems to make this short compared the same intake with carbs and airhorns. Quote Link to comment Share on other sites More sharing options...
skirkland1980 Posted January 26, 2015 Share Posted January 26, 2015 You'll have to open the head a little a long as the port roofs match or the head is slightly bigger. A very small transition on the floor is ok a it can help deflect some air to the roof. Maybe you can lower the intake a little just to get the roofs to line up. I hasd this problem on a sbc. It ran like total crap until I opened up the roof of the head port. Quote Link to comment Share on other sites More sharing options...
madkaw Posted January 26, 2015 Author Share Posted January 26, 2015 I need to do more measuring, but it looks like the head port is about 120mm long-from the back of the valve to the port entry. At the current taper of the intake runner, the taper should blend with the head port at about half that distance. Don't want to just open up the ports and kill velocity, but also want to continue the taper for a smooth transition. With that in mind, don't know if trying to remount the intake to meet roof line will be necessary, but need to stare it more. Don't want to screw up a good head by carving out way too much. Also, size and taper of these runners may dictate a bigger motor then I can afford to build? I still have a lot to learn, but it doesn't seem that 45 intake port entry is not huge. Yes I am trying to build the next motor around this intake, but I will admit that I am still trying to figure out where this intake will perform-highend or lowend. Quote Link to comment Share on other sites More sharing options...
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