spudly13 Posted October 20, 2012 Report Share Posted October 20, 2012 Hey tristin, let me know if you get some l flanges cut, i may be looking for another set! Quote Link to comment
Tristin Posted October 20, 2012 Report Share Posted October 20, 2012 Hey tristin, let me know if you get some l flanges cut, i may be looking for another set! Will do. Im either going to CNC them out since I can do it at my work, or I may have them waterjet out. I havent figured it out yet... I need to finish up my flange model. If anyone here has an L-series model already it would speed up the process immensely. Quote Link to comment
datzenmike Posted October 20, 2012 Report Share Posted October 20, 2012 Also a vacuum supply for the brake booster. Quote Link to comment
Tristin Posted October 20, 2012 Report Share Posted October 20, 2012 Also a vacuum supply for the brake booster. What? Quote Link to comment
spudly13 Posted October 20, 2012 Report Share Posted October 20, 2012 i have a wood template if that would help... when my buddy made mine he cut one out of wood first with the laser, then metal, to make sure it fit, I dunno about tristin but i dont have a brake booster... Quote Link to comment
Tristin Posted October 20, 2012 Report Share Posted October 20, 2012 Lol I was talking about a 3D model... Im going to buy an intake manifold gasket, high resolution scan it, and then model it in SolidWorks... before I cut it out and clean it up. Quote Link to comment
datzenmike Posted October 20, 2012 Report Share Posted October 20, 2012 Aluminum? Quote Link to comment
Tristin Posted October 20, 2012 Report Share Posted October 20, 2012 Yes. I'll be using .5in 6061 plate for the flange and probably .125in wall thickness pipe for the runners. Quote Link to comment
spudly13 Posted October 20, 2012 Report Share Posted October 20, 2012 Lol I was talking about a 3D model... Im going to buy an intake manifold gasket, high resolution scan it, and then model it in SolidWorks... before I cut it out and clean it up. haha, yeah thats what my buddy did, took my gasket and scanned it and then split it up into intake and exhaust, worked pretty good Quote Link to comment
Tristin Posted October 20, 2012 Report Share Posted October 20, 2012 Does anyone else need any L-series flanges? Maybe I could cut a few sets for the DIY guys... Quote Link to comment
slingshot532 Posted October 21, 2012 Report Share Posted October 21, 2012 Got my filters installed. Replaced my fail screens. cut a hole in the hood for clearance. I think it came out pretty cool. In keeping with the spirit of this build they are $7.50 each. Fail screens in mid fail! You can also see my fuel pump and what not in these pics. I am now debating putting a hood scoop over the filters or just rocking it Rat style. Input? *hint* - Build your intake manifold to the right hight so you don't have to cut your hood, if you don't want to have to cut your hood.- Quote Link to comment
Tristin Posted October 21, 2012 Report Share Posted October 21, 2012 I refuse to cut the hood... Im going to be rocking the carbs flat and not at an angle. Are you not worried that water will get into them? 1 Quote Link to comment
72240z Posted October 21, 2012 Report Share Posted October 21, 2012 If going that through the hood rt I would actually bring them up more and put a lexan hood over them like older ferraris did with their air horns. Just for practicality sake. Quote Link to comment
datzenmike Posted October 21, 2012 Report Share Posted October 21, 2012 Does anyone else need any L-series flanges? Maybe I could cut a few sets for the DIY guys... Might be interested. I do like doing things myself though. (Canadian for how much?) I refuse to cute the hood... Im going to be rocking the carbs flat and not at an angle. Are you not worried that water will get into them? I agree. Looks boss on someone else's hood but I could never entertain the idea on something that's mine. Hate louvers too. Sort of a violation somehow. Tristin, had you given thought to tuning the length? Maybe short length then carb then a long tuned length pipe with horn on the end. I guess brake master and strut tower are in the way? I calculate around 14 1/2" from valve head to inlet Quote Link to comment
Tristin Posted October 21, 2012 Report Share Posted October 21, 2012 From what I already know on custom SMIM fabrication, everything is suppose to be a specific size for a specific purpose. What is throwing me for a loop though is that all my knowledge is for turbocharged car applications. You want a large tapered intake plenum, long runners for top-end, short runners for bottom-end... but if youre just running air horns and individual carbs, not a larger plenum and a single TB... Im a little lost. The normal SMIC runner length is 6in (147mm). Thats from head to the base of the plenum. 14in (343mm) might be quite ridiculous for any kind of normal driving. Personally I want more bottom-end than top-end as well I am I going to be running a full filter assembly so I will be designing very short runners. Im in this for throttle response and not power. Quote Link to comment
datzenmike Posted October 21, 2012 Report Share Posted October 21, 2012 You can tune for peak torque or peak HP..... Short for high RPM long for lower. 14.5 is for about 5,800 peak hp for an L20B. Or anywhere in between to fill in or level your torque/hp curve. Peak torque (at 3,800) would have a runner length of 21 inches! The first 5" are the intake port inside the head. Quote Link to comment
Tristin Posted October 21, 2012 Report Share Posted October 21, 2012 I didnt realize you were using internal length in your measurements; I was not. Your calculations make much more sense now... I also remove internal length since its not something you can change like you can change runner length or plenum volume. I see where youre coming from now. Oh and to answer your previous question on flange price: I will have to let you know. Once I cut a set for myself I can see how long it takes to judge a price. If people are interested I can cut a few out. I still have to make a model first before any more of that can be figured out. I think Im going to head into work today to start my model. Quote Link to comment
72240z Posted October 21, 2012 Report Share Posted October 21, 2012 Turbo there is a benefit on the top end from a long runner but most motors predominately follow the opposite school of thought. Its way more important on N/A engine because boost minimizes a lot of negative flow effects due to the brute force. GENERALLY, higher rpm and hp applications require short runners where long runners are for low end tq. Most GM performance v8's after the TPI l98 all use long runners for low tq, pre efi we saw it with raised intake mani's. They made crazy tq. So Does the vg30de in the z32 or any vg/vq in a nissan truck, very long runners with low rpm tq usually higher then its sports car counter part. Most companies have at least one variable intake manifold experiment in the lineup too. Some Nissan vq's came with them. Volvo loves to use them... They use a short runner down low then switch over to a long runner up high. I think there is so much physics involved you shouldn't get too crazy just tune by length like Mikes saying. As for runner shape there is so many things out there people say about this or that. Idk but I know most n/a motors seem to be using straight tube runners of one shape or another. There are other things to keep in mind besides flow into the cylinder too. My Mikuni manifold has a ridge at the lower end of the runner. Regular thinking or internet reading would suggest thats bad because the runners should be port matched to increase flow and reduce turbulence Mikuni says its for anti-reversion Which actually is a problem on dcoe L series. More so on ones with a came increasing valve overlap. The overlap allows exhaust to backwash into the cylinder messing with the A/F mix and combustion. Idk if the ridges work but I trust Mikuni. Headers supposedly help this as well leaving the gas further away then on a common mani. I imagine the problem exists in a bike carbed L series just as it does in a dcoe equipped one. Quote Link to comment
Tristin Posted October 21, 2012 Report Share Posted October 21, 2012 See... like I said, all my knowledge is with forced induction. I havent owned an NA car in about 11 years. This is also my first non-AWD and first RWD is about as many years. My main plan is building the runner length to work with my filter choice. Thats not a very proper way, but its whats important to me so thats whats going to happen. Ive taken some preliminary measurements and I will have an adequate manifold based on my requirements. Quote Link to comment
72240z Posted October 21, 2012 Report Share Posted October 21, 2012 Hey man build it for what you want, if its for filters to fit go for it. Remember you can use bends to gain length while also fitting filters. I like the topic so just felt like rambling on lol. A few years ago I started a thread on hbz on the topic. After finding a pic of the r26b variable intake and being awe struck. They constantly move in and out as rpms change. So hot...... Quote Link to comment
Tristin Posted October 21, 2012 Report Share Posted October 21, 2012 Well none of the local stores have a gasket I can use to model. I thought I had a complete gasket set in the garage, but no manifold one... Oh well, should be here tomorrow or so. Then its on! Quote Link to comment
slingshot532 Posted October 21, 2012 Report Share Posted October 21, 2012 Would it be bad to drive this in the rain with the carbs exposed? motorcycles do it all the time, no? We don't get much rain down here anyway, just enough to get the car dirty. And I don't park it outside. Quote Link to comment
Tristin Posted October 21, 2012 Report Share Posted October 21, 2012 Well they are pointed straight up... so even the slightest amount of water would run down into the engine. Quote Link to comment
INDY510 Posted October 21, 2012 Report Share Posted October 21, 2012 Would it be bad to drive this in the rain with the carbs exposed? motorcycles do it all the time, no? We don't get much rain down here anyway, just enough to get the car dirty. And I don't park it outside. I wouldn't reccomend it,, you'd be sucking in more water than gas ..... . and R1's/sportbikes have airboxes under the gas tank... so no water can get past the intake inlet, then the foam filter, then into the air-box around the carbs/air horns Quote Link to comment
datzenmike Posted October 21, 2012 Report Share Posted October 21, 2012 Ask Punkin Dave what he did. Make a snap on hood scoop that faces to the rear. Quote Link to comment
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