so cut the throttle wire on the car, comes up on the revvs now. but i have a boost leak now, some how :/ take everything off tonight make bracket stronger. should have boost hopefully :)
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Out of curiousity how did you run your piping? Positive Displacement blowers don't really like being far away from the intake ports, and long tubing runs can really hurt their efficiency. This could be part of your issues with not building boost. Also, how did you seal your tubing flanges to the supercharger. If your still using that thin gauge metal for the flange that will easily bend away under pressure and cause a huge leak. Your going to want AT LEAST 1/4" metal for that, but I would play it safe and go with 3/8" so you know it won't be flexing anymore.
Oh, and what is the diameter of your crank pulley vs. charger pulley? That should tell you what boost you could expect, so you know how much your missing.
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I said this before. Supercharging is another ballgame on petrols, oldskool diesel is easy.
Theres NO way miller this and that would do it.. You would need a standalone EMM.
Oh, and.. If were following the 1bar boost = twice the power. Remember, the blower is stealing 30 hp.
And then there is the heat..Last edited by Kvasi; 08-10-2012, 08:04 PM.
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Well everytime i try to give it throttle it will revv up but then it will stop at 4800. I dont know how big the pulleys are i will measure them today. Im going to redo my my flange and bracket today with my buddy Kamotors, who has been helping this whole time. But he says that when i get boost my flange might be ballooning out causing the boost to go into the intake side of the blower causing that stutter.i did use the stock gasket and chrysler RTV to seal it. We also think that i could have a intake manifold leak and all my boost goes away. But that's kinda rare right? I have to reconnect the exhaust on the e so i can go get my tools but either today or tomorrow i will let you know whats going on.sigpicDiRTYE30-RALLYE30
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OK. So. took everything off this morning, meaning bracket and manifold. might have had a small leak into the next chamber over, but not into the intake side. I reinforced the bracket a bunch so i could tighten and not have it bend. Put all of that back together, manifold with much more RTV this time. We did a boost leak check, and my blow off valve was leaking really badly. Took that out, one its not to good for the blower i read, or something and two it was leaking like crazy. Took that out and the car was running better, took it down the street and the outlet came off lol. Fixed that with a better clamp, took it on another test drive and still no boost, it needs a tune job. Anyways measured the pulleys they are kinda really small. 2.795in.. on the blower and 4 1/2 or 3/4 on the crank pulley i might only be getting 3 psi, because im barely reaching 0 vacuum. Does any one know of a crank pulley that could fit that's like 8in with the same or close bolt pattern, or even what pulleys i should be running? Another thing. Cannot take off blower pulley because its welded on. Thanks for the help so farsigpicDiRTYE30-RALLYE30
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Originally posted by e30leigh View Postits not uncommon for an intake mani leak. have you replaced the gaskets? if not they might be brittle and the added pressure can effect them alot.sigpicDiRTYE30-RALLYE30
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so here is how to calculate boost
"Boost (psi) = (PR x 14.7 x V / C/2 ) - 14.7 - I
PR is pulley ratio, crank pulley diameter divided by drive pulley diameter. e.g. The stock Jaguar M112 pulley is 3 inches in diameter, therefore 5.5/3= 1.83
14.7 is the pressure of the air we live in, we don't live in a vacuum, we live in 14.7 psi.
V is the volume of the Eaton blower for one rotation. The M90 is 90 cubic inches or 1475 cc. The Eaton M112 is 112 cubic inches or 1835cc. Turn it once and it pumps out 1.835 litres of air.
C is capacity of the engine in cc : 4000 cc for the 1UZ-FE. The C/2 is C divided by 2 - because for one rotation, a four stroke engine is only half way through a complete cycle. When the piston is up the top and starts going down, air and fuel go in, then it gets to the bottom and goes back up and compresses the mixture. That's one rotation. Then the spark plug ignites the mixture and it starts to go down again, it gets to the bottom and then goes back up again pushing the burnt mixture out the exhaust valve and returns to the top to start over again. That's two rotations.
I (capital "i") is an allowance for boost lost due to valve overlap. All engines have valve overlap; the intake valve opens before the exhaust valve closes - the incoming fresh air and fuel pushes out the last of the burnt exhaust gases. The 1UZ-FE has a small overlap of only 9 degrees. Nissan's RB26DETT has 14 degrees, Subaru EJ20 has 16 degrees and the turbo EJ20 has 14 degrees. The allowance is quoted as 5% boost lost for every 10 degrees of overlap. So for the 1UZ-FE at 6 psi boost, perhaps boost loss is 0.05 x 9/10 x 6psi = 0.27 psi lost - it's not much."
7speedshop.com
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Originally posted by kamotors View Postuh oh.....calculations say your only getting 1.007psi:( that would explain a lot.
Boost (psi) = (PR x 14.7 x V / C/2 ) - 14.7 - I
PR = 4.75 in / 2.795 in = 1.699
V = 62 in^3 (Eaton M62)
C/2 = 2.5L/2 = 1250 cc = 76.27 in^3
Boost = (1.699 x 14.7 x 62 / 76.27) - 14.7 = ~5.6 psi
This seems more in the ballpark just because the stock crank pulley is probably close (possibly a little smaller, but not drastically) to the original diameter of what drove the charger in it's original application.
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So i need a new pulley regardless. Also i didn't do research i'm retarded, the blower came out of a Benz c230, and apparently those are 1.8 liters so the small pulley works. Also their crank pulley is 7 and something inches so they can get 12 psi stock. So since I have more displacement therefore i need larger pulley, like 10-12in. to even get some boost to over come valve junk and the 30hp the blower is stealing away. What i figured, and i assumed, it always gets you in trouble, that its like a motor cycle chain and sprockets, the bigger crank pulley gives you more speed and then the small rear would give you more speed. But now math is involved :( hahaha. So any suggestions on what the dimensions are on an 12in crank pulley or how i could get those measurements?sigpicDiRTYE30-RALLYE30
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Originally posted by TheBlik View PostSo i need a new pulley regardless. Also i didn't do research i'm retarded, the blower came out of a Benz c230, and apparently those are 1.8 liters so the small pulley works. Also their crank pulley is 7 and something inches so they can get 12 psi stock. So since I have more displacement therefore i need larger pulley, like 10-12in. to even get some boost to over come valve junk and the 30hp the blower is stealing away. What i figured, and i assumed, it always gets you in trouble, that its like a motor cycle chain and sprockets, the bigger crank pulley gives you more speed and then the small rear would give you more speed. But now math is involved :( hahaha. So any suggestions on what the dimensions are on an 12in crank pulley or how i could get those measurements?
One more thing for it to be done right the throttle body needs to be located before the charger...(ask me how I know) of course dont listen to me what do I know about Supercharging the M20..how are you going to do that now?!? now that u located the roots charger under the exhaust which is just rediculous for a lot of reasons how are you going to relocate the throttle body? Why do you think you need a 3.5MAF? why cut the throttle wire? why use weak ass small gauge metal for mounts or sc output? I could go on and on...Last edited by Denny; 08-12-2012, 08:00 AM.Denny
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