torxxx Posted February 5, 2009 Share Posted February 5, 2009 Just got done emailing back and forth with redline about gettin a 38dgas for my lifted wagon. I was tempted with the 32/36, but I like the gear drive linkage vs the standard linkage on the 32/36. After talking with Bud at Redline, I'm wondering how much they talk up their carbs. Granted yes it is a upgrade from a hicrappy carb, but some of the stuff he said seemed far fetched. This is from the e-mail "This package is exciting but I would sell this with the above comments then offer to work with you to deal with any issues that come up and I believe you will be absolutly surprised with the gains its like going to a 6 cy with out the engine swap over our progrressive carb package." Making a 4 cylinder seem like a 6 cylinder with just a carb swap doesnt seem right to me. Like I said it is a step up from hicrappy carbs, but honestly they cant make that much of a difference considering the displacement, and the small size of the ports on the head and on the intake. My exhaust is very free flowing (no cats 2 inch y'd together about 4 feet back going to a hi performance muffler) But other than that, I dont see where all this "magic" power is going to come from. MSD Ignition, 8mm wires the 14 dollar a piece iridium plugs, SPFI block with shaved heads. I plan on getting some cams done from Delta also. So yeah I will have small gains but 6 cylinder power? Maybe if its a 1.8L 6 cylinder. I also have access to a 2.7L kinda wondering if I should rebuild that and bolt the 38 DGAS to that instead. I'd like you guys input on this. Plz state engine (ohc/ohv) and carb sized and what you use the rig for. Also Jet sizes would be fantastic. I'm trying to run all numbers and senarios that I can to make this work just right. Thanks guys Link to comment Share on other sites More sharing options...
GeneralDisorder Posted February 6, 2009 Share Posted February 6, 2009 He's a salesman - what do you want? They provide better low-end torque on a stock engine. Beyond that they really do nothing at all on the high end because no changes in the mechanicals have been realized with only a carb swap. Mostly they rely on the fact that the carb is both new, and that people who are using them are more likely to "enjoy" the progressive linkage's jumpy nature as opposed to a worn-out carb with a vacuum secondary that may or may not be working. Seat of the pants it feels more "sporty" and more responsive, and the low-end improves due to the larger barrel sizes. But that real performance numbers don't change in any appreciable way. SPFI is just as good and has better driveability characteristics. GD Link to comment Share on other sites More sharing options...
TomRhere Posted February 6, 2009 Share Posted February 6, 2009 No, a Weber 32/36 won't turn your 4-banger into a 6-banger. But it will wake it up a bit. I'm running one on a stock solid lifter EA-81 in my '86 BRAT, carb is mounted on an EA-82 carb intake. Carb was originally bought and installed on an EA-82, jetted however they do for one of those. Stock Y-pipe dumping into an XT6 mid-pipe with no muffler. She runs down the road pretty good, and gets 28 MPG in warmer weather. Have hit 30-31 a couple times. I would imagine that if you swapped in a beefier cam, SPFI pistons, P&P the heads, maybe even mill them a tad. You could gain some decent power over stock. Link to comment Share on other sites More sharing options...
torxxx Posted February 6, 2009 Author Share Posted February 6, 2009 yah I've been a fan of bigger is better so unless someone speaks up and says horrible things about the 38 DGAS I think I'm going to go with that one. I can always jet it down some if its getting too much fuel I wish the 32/36 had the gear drive linkage, I'd get that one in a heart beat. Fuel Injection, eh, just more to go wrong. I have several FI intakes and harness's in my shop but I really dont wanna get into wiring to a SPFI. If I am gonna deal with wiring I would do the 2.2 or 2.5L swap (have the adapter plate and harness for odb2 2.5 just need the flywheel/clutch) Either of you guys that posted know Jet sizes useD? Link to comment Share on other sites More sharing options...
GeneralDisorder Posted February 6, 2009 Share Posted February 6, 2009 (edited) Either of you guys that posted know Jet sizes useD? Unlikely that you'll find any - no one in this community runs the DGAS - no one that has any carb tuning experience anyway. You'll have quite the fun time learning with it and messing with air correctors and emulsion tubes, I can tell you that. I've been closely involved with tuning a DGV on a 1.3L Samuri engine with a custom VF11 blow-through install. Emulsion tubes are like black magic - the art of tuning this stuff died with the engineer's that designed them. The good news is that there are many arcane volumes availible on the used book shelves that yeild a wealth of information if you bother to blow the dust off. As far as the FI - there's very little to go wrong with the SPFI setup. It's just a matter of if you like troubleshooting with a screwdriver and investigative mechanicing or with a DMM. Fortunately I am handy with both. There are reasons to prefer either but thankfully I don't go to 3rd world countries where the virtues of an all-mechanical system would be applicable due to the availible technology level. GD Edited February 6, 2009 by GeneralDisorder Link to comment Share on other sites More sharing options...
abog Posted February 6, 2009 Share Posted February 6, 2009 All carbs do the same thing, dump fuel. Where the real difference comes in is how they transition from idle to wot. Probably any new carb is going to feel better than an old one . Definitely a salesman. Any EFI set up will work better because they are far more efficient. The problem is most folks are used to carburators in performance applications and are reluctant to go EFI. They feel there is to much magic involved. Link to comment Share on other sites More sharing options...
torxxx Posted February 6, 2009 Author Share Posted February 6, 2009 Let me put it this way, I'm a mechanic. 95/100 cars that come in my shop with emission related problems or fuel mileage problems are fuel injected systems. the other 5/100 are carb'd. Reason why I'm asking about the webers is because I've never worked on one. Everything here in alaska is holley or edlebrock. Not because there isnt carbs left alive up here, but because they are a simple fix. rebuild the carb or buy a new one. You dont have an electrical system that goes nuts if a ground wire comes loose, or if a pin gets bent. you also dont lose cat converters because an o2 sensor died and told the engine to dump raw fuel into the engine, causing the cats to plug up solid. You dont have ECU problems because some idiot hooked up jumper cables backwards. You dont get a misfire on 3 cylinders because a coil pack is dying. No rev limiters, no fuel pumps that require the fuel tank to be dropped to replace it. I can go on and on all night pointing out the drawbacks to Fuel Injection compared to carbs. I really dont care bout mileage at all this hicrappy gets 15 mpg if I'm lucky. I figure if I'm going to spend 400 dollars on a new carb, why not move up in the world. Basically what I'm saying here is simplicity. Once a carb is jetted correctly (which I have someone who builds fuel systems for airplanes, jet boats, air boats etc is going to tune this carb for me if I go this route) you are done nothing else to go wrong with the fuel system other than fuel pump, filter or the carb. And the fact that I can carry a spare carb, fuel filter and pump with me when I am 100 miles away from a phone or people and knowing I can replace all of that in 30 minutes and be back on the road. Fuel injection, well I wont even get into the thousands of dollars of parts that could break and need a ODB scanner/computer to replace, adjust etc. Sorry to ramble about this, but I've gotten this whole "just go with fuel injection: from almost EVERY one I've asked about upgrading carbs. I might be young compared to a lot of the users on this board, but I still say 1980s technology is the best for offroading and fast, cheap fixes oh and GD, I have no problem working on FI systems. work on them every day, Easy to fix when you have someone else paying for the parts. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted February 6, 2009 Share Posted February 6, 2009 The one thing you failed to realize though is that all these problems you have pointed out are a result of poor design and the government stepping in to mandate higher complexity. The drawbacks you give are not inherently problems with FI, they are problems with the fuel injection that YOU have worked on and have experience with. I will not argue that the modern FI systems are replete with obfuscated components and systems designed only to keep the bunny-huggers at bay rather than to actually make it run any better. One of the big differences with the SPFI is that it was a very early FI system and by virtue of the very nature of FI in general it was far more accurate and economical than any carb - thus the complexity of the modern systems was not needed for it to outshine it's rivals of the period. There is no OBD - no scanners required - it's computer has a self-diagnostic mode. There are no additional parts beyond what is absolutely needed (no special emissions systems were equipped), and the 4 components that could cause you a problem are all easily carried in the same size box that your spare carb would be carried in. It's a matter of what you like. Carbs have their place too. I have two rigs I drive regularly - an 83 hatch with a DGV, and a 91 SS with a turbo MPFI system (also early, and without the modern extraneous paraphenalia). The driveability of the hatch is not as good..... to say the least And if your Hitachi gets 15 MPG..... I would say there's a good chance you have other issues. Have you checked your compression? GD Link to comment Share on other sites More sharing options...
Jerry DeMoss Posted February 6, 2009 Share Posted February 6, 2009 I have a spare weber 38dgas laying around for such an occasion. I want to try something different as well. Link to comment Share on other sites More sharing options...
torxxx Posted February 6, 2009 Author Share Posted February 6, 2009 compression is fine, checked it last tune up (10k miles ago) The engine is still strong only 100k miles on this engine problem with it is the primary drips fuel bad when it idles, so I lose a bunch of mileage that way. I've blasted out the air vent to the primary and stopped it from dripping for a little while, but the vent plugs back up and fuel starts dripping again. I can let my car idle all day at work and burn 1/3 tank of fuel. Granted my driving isnt that great for mpg either, but 3 years ago the car got 22 mpg with an engine with 300k miles on it Either way, on the early SPFI, I guess with the exhaust system tahts on my car now, I dont want cats which is why I built my exhaust myself. If I were to go to SPFI, how am I going to deal with out a cat and the 02 sensor? I've heard lots of stories bout ways to trick the ECU into thinking that the car is running emission wise like it would with a cat on it, but no ones ever been able to say, Yes that trick works. One of the ones I've been told the most, is put the O2 sensor back as far as you can so the exhaust gases have cooled and are supposedly cleaner? Dont make much sense to me, but yeah.. I guess if I was to goto FI, megasquirt with a central fuel injector would be the way to go? (bypass EGR valve also?) Link to comment Share on other sites More sharing options...
GeneralDisorder Posted February 6, 2009 Share Posted February 6, 2009 The O2 on the SPFI's does not require a cat. It's before the cat and is only used for mixture control, not to check the effeciency of the cat as in newer forms of FI. My SPFI converted Brat has no cat - I cut it open and gutted it then welded it back up. You drill a hole and weld in a nut to screw the O2 into. Takes 10 minutes. I think you are under the impression that the O2 is for emissions purposes - that is not correct. The O2 is used to fine tune the cruise mixture for optimum economy. It is not an emissions testing device. Generally on newer rigs they will use a secondary O2 sensor to determine the effeciency of the cat. That can almost always be deafeated by adding a spark-plug defouler between the exhaust and the sensor so as to pull it back out of the exhaust stream a ways. But that's academic as the SPFI uses only the simple single O2 system. MS can run the SPFI, but for most purpose the stock ECU is fine - not to mention cheap. EGR can be left alone. The SPFI has a solenoid for it, but otherwise cannot sense what it's doing. Leaving the solenoid hooked up will prevent a CEL but replacing it with a 33 Ohm, 5 watt resistor will do the same thing. The ECU is dumb on the subject of the EGR and Purge solenoids. It mearly wishes to see a resistance - it cannot tell if they are working and doesn't care anyway. GD Link to comment Share on other sites More sharing options...
abog Posted February 6, 2009 Share Posted February 6, 2009 If your carb is dripping at idle, have you checked the float level? Link to comment Share on other sites More sharing options...
naru Posted February 6, 2009 Share Posted February 6, 2009 Just got done emailing back and forth with redline about gettin a 38dgas for my lifted wagon. I was tempted with the 32/36, but I like the gear drive linkage vs the standard linkage on the 32/36. ....... Thanks guys I would expect inferior low speed throttle response from the 38/38 due to the synchronous throttle linkage and small engine size. At low speed,there will be 1/2 as much air flowing through a venturi. Less air = less vacuum to pull fuel into said venturi. Top end is nearly the same,270 cfm vs 330cfm. Venturis are nearly the same,26/27 vs 27/27 I`d go w/the 32/36 Link to comment Share on other sites More sharing options...
torxxx Posted February 6, 2009 Author Share Posted February 6, 2009 GD - Im familiar with using resistors to trick the ECU into thinking the part is still there and functioning.. had to do it a lot with 1990's chevy 6 cylinders and the knock sensors. Also can be used to bypass the VATS security system on older GM cars. As for the 02 controlling emissions I realize it isnt directly related to emisson control, but up here they test your vehicle at 2500 RPMS for 3 minutes for the IM test, and the O2 sensors do come into play for the high speed testing. Engines running lean (or o2s say it is) engine dumps more fuel causing higher emission output on the top end of the test. Have had many vehicles fail because of bad 02 sensors As for the everyone that chimed in, thank you you've pointed lots of useful information. I may just goto the junk yard and get a 32/36 and fab up and adapter plate for it and play around with it before I go out and buy a new one Link to comment Share on other sites More sharing options...
GeneralDisorder Posted February 7, 2009 Share Posted February 7, 2009 and the O2 sensors do come into play for the high speed testing. Engines running lean (or o2s say it is) engine dumps more fuel causing higher emission output on the top end of the test. Have had many vehicles fail because of bad 02 sensors That's true but the SPFI could care less about the cat - and the O2, while potentially causing an emissions failure if not replaced every 100,000 miles or so (a massive $20 fix!), will not strand you somewhere if it isn't working. You can disconnect it and about all that will happen is your cruise mileage (freeway, etc) will go in the crapper. It will still run just fine as the O2 is not used for except for idle and cruise. It is not used for acceleration or WOT operation - it isn't used when any mixture other than stoich is required. GD Link to comment Share on other sites More sharing options...
Snowman Posted February 8, 2009 Share Posted February 8, 2009 Not to rain on your parade, but I ran a Weber 32/36 DGEV on my EA82 for a while, and it HATED the cold in Anchorage, which is nothing compared to the cold in Fairbanks. It was a new carb from Redline, set up for an EA82, so there wasn't anything wrong with it. I was later told that running a hot air pipe up from the exhaust, like on the stock hitachi setup, would help with the running (I think it was trying to ice up under some conditions), but that would have nothing to do with the fact that it took FOREVER to start if it wasn't plugged in below 25 degrees or so. For cold weather, you're better off with a properly running Hitachi or an SPFI setup, as both of those will start right up and run well at virtually any temperature. My experience with the SPFI systems is that they're quite reliable, and most of the issues that do come up will not leave you stranded without warning. I've only seen two common problems with them. The MAF sensor gets dirty causing lean conditions under load and requires cleaning, which is no big deal, or the coolant temp sensor starts giving false readings, causing hard starting at times, but that's easy to diagnose so again it's no big deal. Compared to the rest of the issues with an EA82 car, such as timing belt failure, CV axles, and cooling system problems, the SPFI system is pretty reliable. Link to comment Share on other sites More sharing options...
Snowman Posted February 8, 2009 Share Posted February 8, 2009 And if your Hitachi gets 15 MPG..... I would say there's a good chance you have other issues. Have you checked your compression? GD BTW, low MPG numbers are pretty common up here, mostly in the winter. It's mostly caused by the conditions, but I know in Anchorage they use a differently formulated fuel during the winter that is more volatile for easier starting but has less BTUs in it....kind of like winter diesel fuel. My fuel economy always goes to crap when it gets below zero...I calculated 12 mpg one time in my EJ22 Legacy going over some steep passes when it was -45 degrees out, while the same car gets 25 mpg in ideal conditions. Most people I talk to average 18-20 mpg in mixed city and highway driving with their newer subarus, so for a lead foot driver like Torxxx to get 15 isn't all that out of line. Link to comment Share on other sites More sharing options...
torxxx Posted February 8, 2009 Author Share Posted February 8, 2009 kelly I've found a fix for the preheater tube. Use a air cleaner assy from a 2.8L S-10 with a 38dgas on it. its got the tube and vacumn diaphram on it u just gotta spin the 180 degrees.. So I decided to tear into my carb today. Float bowl gasket was shot, float lvl was too high. primary venturi vent was plugged. Replaced needle valve on float bowl.. cleaned the primary venturi vent and the secondary vent tube. After carquest sold me a carb kit that was already opened and someone took pieces of out it and returned it to the store, I got lucky and napa had the right kit I needed in stock. Put her back together, left the little spring clip off of the needle valve because it really shouldnt be there because it stops the float from stopping the flow of fuel primary venturi STILL drips fuel.. WTF? Car does have more power with the top end rebuilt.. I did have a problem getting the brass deal that the needle vavle for the float sits in out. I couldnt get it to turn at all so I left the old one in there. anyone else got ideas on the venturi vent still dripping? oh and I decided to head test my engine today... bad head gaskets.. engine has NEVER been overheated... runs fine, no white smoke.. kinda wierd. :-\ Link to comment Share on other sites More sharing options...
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