Hi I am new to this site so please excuse the ignorance. Have a 74 2 dr Mav and hope to have a pic up soon but to the question. Have a 302 and a Paxton supercharger sn 89 and can't decide on fuel delivery. Price is always a factor. Thinking blow thru set-up but having trouble finding info. Just wanted to know if there is anybody here running that kind of setup. Heard Demon carb are no good Heard Holley can be modded easily Heard Eldelbrock can be modded but tricky (cant find any info) CSU and TPC make a carb ready to race but $900 plus shipping EFI is great but looking at $3000 any response is a good response
Check out Turboforums.com, it used to be Turbomustangs.com it has some great blow through information. My opinion is to go with a Holley. You can mod it yourself if you have access to a wideband oxygen sensor or have CSU build it for you. The fuel system is key to making it work. A good boost referenced return style regulator and the most massive rediculously big fuel pump you can afford. There is a lot of information there on fuel injection also, but I wanted the retro look for mine. Do some studying and good luck!
I prefer draw through because it is less complicated but it is also not used as much. I think it must have more lag than the blow through. Hp Books has a How to artical in one of their books about how to mod the Holley for blow through applications. If I can find it I will post the book title and number.
CSU and TPC carbs are the ONLY way to go. I know, the carbs arent' cheap but how much more does it cost to rebuild the shortblock after you grenade it a couple times during the "tuning" process? Trust me....I've been there! CSU usually can hit the nail on the head if you give them all your information. Meaning that they can get the carb almost spot-on the first time. I met a guy a while back at the drag strip that was running an old Monza with a blow-through turbo small block. Thing had no intercooler, a MP T-88, pretty much a stockish dart block shortblock, Brodix heads and intake....and it was stupid fast. I believe he was running 5.60's in the 1/8. It too had a CSU carb on it. I asked him about the carb, and he explained that they actually built the motor at home, fired it up with an older Holley and then bought it to the dyno to have it tuned. The dyno operator swapped that old Holley out for the CSU carb and it picked up over 100 HP and best of all, it cured the lean/rich condition. It was a brand new CSU that was actually built to THAT engine combination and they went on to say that no jetting was required. Impressive! That said, it is possible to mod your own holley but I speak from experience (I've done this before) when I say that it's cheaper in the long run to buy the CSU or TPC carb. And as for blow-through vs. draw-through, blow through is always easier. Draw throughs usually will have fuel puddling problems not to mention the seals on the blower will be used up pretty quickly. Also because the blower's compressor wheel spins at 20,000-60,000 RPM, the tips of the blades tend to wear pretty quickly when they are exposed to fuel. The centrifugal blowers just are not designed for draw through. You have the same problems with turbos--seals leak under vacuum, blades wear, fuel puddling issues, and a host of other problems. The folks at csu, tpc, and others have gotten blow-through down to an art now, and the days of the old saying "blow through doesn't work" are history! blow-through carbs work ALMOST as good as EFI now!
Thanks for all the replies! I want to go blow through because of the intercooler effect of atomization. Modding an ebay $100 holley 750 carb for blow through is cost effective . http://www.hangar18fabrication.com/blowthru.html has lots of info the mod procedure. Has anybody done it??? I am a licensed aircraft mechanic kinda handy kinda a hack! Anybody know where to get a carb hat or a cheap way to fab one up? Wideband: A buddy and I are tuning 2.3l turbo (25psi) in a 94 ranger with innovative system with logging very goood system but pricing. Any good alternatives??
Yes it sounds cost effective at first BUT I am speaking from experience, unless you know your way through a Holley (I mean you must KNOW EVERYTHING), you'll spend many hundreds of hours playing with pvcr's, idle air bleeds, high speed air bleeds, idle feed restrictions, float levels, power valve sizes, vent tube design, jet sizing, sealing the throttle shafts and top air horn, and much much more. Plus, if you're like me and you don't know exactly what you're doing, chances are you'll nuke a shortblock or two. That's what I did. Yes that's the site I used, along with http://www.toohighpsi.com. Both of them were helpful but it STILL isn't a CSU. Some of my problems were due to the hat design which wasn't too nice for fuel and air distribution, that and the headers. Both were made here at home, cheap. Is that the LM-1 or LC-1 system? Both work excellent and sooner or later I'll buy one myself. They are the best out there, IMO. WELL worth the money! There are cheaper alternatives but basically you have to do some shopping. AEM makes a WBO2 system...cheaper but nowhere near the quality and their low-end WB is nothing more than a sensor, controller, and gauge. Try reading that gauge while attempting to control a 750 HP turbo V8 on the street. It's nearly impossible! You NEED datalogging, period. You can get close with a cheaper system with a gauge only but it won't let you know exactly what's going on at what RPM. Of course, that's all my opinions. do what you want, but trust me, I've been in your shoes and if I was to do another one, I'd do it completely different than the last one I did. changing head gaskets, pistons, plugs, etc is not exactly fun when you could have spend $400 in the first place and had it up & running GREAT. Have you looked at megasquirt EFI?
Haven't look into megasquirt but keep hearing nothing but good things about it! The wideband system is the lc-1, my buddy will lend it for tuning but i want to have a guage in the car at all times. LC-1 is compatible with Megasquirt have heard the atomizing effects of carb are a great bonus. Will look into megasquirt. P.S. you sound like you have learned the hard way, my condolences, life is to short to make all the mistakes yourself. Thanks for the honesty on the holley stuff!
Mavman is correct that you want to have data logging. We use the LM-1 in my buddies n/a car, but all the add ons for boost pressure and EGT made the system too pricey for me. I went with the Zeitronix. It's a little cheaper system with less expandability, but it does have the RPM, boost, EGT and A/F (lambda) ratio datalogging standard. Being the cheap b@!?#ard that I am, I built my own carb. But if I had the expendable cash I'd do the CSU deal. Having said that, I feel that I've researched it enough to know what I'm doing and I've tuned carbs for the last 30 years. So in short, I'm going to go for it. I think that if you take it slowly and step by step it can be done. Visit Turbomustangs.com, there are guys that have gotten it right there and ones that are struggling. Check out what they have to say...they are a wealth of information.
Don't even start the engine without a wide band of some type (i use the LM1). Another alternative to a hat is the complete carb enclosure. Less carb hassles with this set up(no throttle shaft seals, etc). You will still need a boost referenced return style regulator(A GOOD ONE). Still any setup you use requires a lot of Carb. tuning. So like the others say if you do not know and or scared to learn, its best to buy one already close to what you need. Most Carbs that are set to blower specs are always set to the rich side, (better to err on this side as to be lean) But if you are not trying for fuel mileage and performance these carbs work fine. (yes you can have Both, My car runs mid 6's @3400# and gets upward of 16 mpg, if drove rite) . We are contemplating a build up like this in the future with a F3 blow Thur setup, so keep us posted on your results.
My poblem with the carb enclosure is sealing and tuning. Here it is a pain in the "@$$" to tune when every 1/4 turn adjustment requires 12 bolts to be removed and try to get a screwdriver on the idle mixture screw. Will go with a hat. Seen a pretty scary custom built walmart stainless steel pot modified to be a hat. Just cost the guy 15hrs of tin bashing and $14 dollars. Was it really worth it?
