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Discussion Starter · #1 ·
I am now going to rebuild my 302 that I was using for drag it is in a 81 mustang coupe. And I am wandering wich will be better twin turbo or 8:71 supercharger. wich one will be more power? wich one is the most expensive? I want something really powerful. thanks
 

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matts94sc said:
I am now going to rebuild my 302 that I was using for drag it is in a 81 mustang coupe. And I am wandering wich will be better twin turbo or 8:71 supercharger. wich one will be more power? wich one is the most expensive? I want something really powerful. thanks
How much you have=how fast you want to go!!!
 

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An 8-71 is WAY too much blower for a 302. Before you get your mind set do a little research. Either way you go blower or turbo is not going to be cheap. Look up the list of parts you will need to do it right and then add another 40% to that. I don't know about you but, when I was 20 there was no way I could come up with the ~$6000+ on top of the engine build. If you have the means to do it then go for it. I think you should set your goals a little lower, that is a lot of power for a young man to have. Will this car be street driven? Have you ever built an engine before?
 

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Discussion Starter · #4 ·
I have already built 1 302

i have built one 302 already threw $5000 in it. it has about close to 550ish on the bottle. but my cousin has a 67 nova two door with a 383 stroker witha 8:71 on it And I love it And yes i can handle it. I have been raised around it when i was 14 I drove a 71 duster with a 440 built in it It was awesome. I am looking to build anither 302 for full drag no street @ all. money isnt an issue Im not expecting to build it in a year anyway Im going to take my time. do the car then the engine. I thought about a twin turbo kit I can get EVERYTHING hoses,tubing,clamps,turbos,headers,intercoolers,wastegaste,blowoff,fuelpressure reg, for my application for $1500 for all of it. and it is for my application. now that wont even buy a supercharger for my 302 not even the base. so some more info would help thanks Oh by the way what i meant by 8:71 was a supercharger I didnt mean that one inperticular just a supercharger. thanks!!
 

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Discussion Starter · #10 ·
already forged out

well im planning on running A dual carb setup. and i already have all forged bottom and top end with about 9to1 compression. and it will be a twin turbo setup with the intercoller and all for round 1500 with everything no running to the hardware for anything complete bolt on kit. headers all of it. could i run a dual four setup with one turbo for the back and the other turbo for the front? or would just one carb be better? or whats the best route??
 

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Too much compression. Go back and read RippinRon's post. I agree with him also about the EFI, but a carb is simpler for me since I know squat about EFI.

One carb with a blow-through bonnet on it will be simpler and cheaper I think. There was an article in...I think...Car Craft a couple of years ago about a guy here in Phoenix with a twin turbo big block that ran one carb and a bonnet and it made tremendous power. He used generic off-the-shelf turbos. Give these guys at Arizona Turbo a call and discuss the cheap and easy way to do this. 602-253-9953
 

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It's gonna be expensive. I have $2,500 ( currently, still need some more parts ) into a 200 Ford I6, that is getting turbocharged, using a free turbo. did I need the $545 roller rockers, probably not, but I got them because I know there quality, somthing the factory rockers lacked in ( I have 3 sets of factory 1.5 ratio 200 Rockers, there all crap, you can see diffrences in the angles ). did I really need the MSD 6 BTM, no but now I know it will be ok, and not detonate. parts I actully needed, the Turbo bonnet alone, was $92 from summit. granit, I'm doing a compleate rebuild. when the car drove in the shop, it was a bone stock 200 I6 Ford Falcon grandma car, that wouldn't idle unless it was warm ( idle circuit in the carb didn't work right after carb rebuild )
 

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Discussion Starter · #13 ·
already have most of that

well, I already have for racing full roller rockers 1.6 ratio, petejackson gear drive, msd 6al ignition,taylor 409 pro race wire. msd hei distributor, speed pro forged flat top pistons, eagle forged crank and rods. factory ford heads with a full port and polish. I will be replacing those later. now has an edelbrock rpm intake with a holley 750 double pumper. bbk shorty headers with 3inch pipe past the seats just hangin with dynomax bullets on the ends. I also have a offenhauser dual 4 intake that i was going to use with my turbo setup but i guess it would be easier to use just one carb not the one I have now but just a single carb.
 

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Matt
You will also need a bottom end stud girdle to hold all of it together. I am assuming of course you have a two bolt main at the bottom end. Forged crank??? Wonderfull!...Now get the girdle on it so you can stress that steel crank!
______________________________________________Rick..........
 

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turbo lag......yeeeeehaaaaaaw
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Are you getting your kit from ebay? If you are I would send the turbos out to get balanced. I have heard they can be way off. Dont forget to prime your turbos before you turn the key. If you dont you can destry that within minutes. Since you have a 6AL just add a BTM unit to it and you could run 10psi on pump and turn it up when you get race fuel. I would forget the dual quad setup and just use a single 750 set up for blow through use. I would also use a victor jr intake or a similar single plane.
 

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Discussion Starter · #16 ·
thank you all

ok have them balanced? I will do that. so use a singel carb? can i use a regular 750 double pumper? cause I have one of those already its a holley classic 750 double pumper. or does it have to be one of those blow through carbs?? so I can use a victor? Is that what you recommend?? i was thinking about a weind or holley single plane. but you all know the best I will only be running race fuel, pure VP nuttin else. I going for full drag only. and yes the stud girdle is next on my list I was going to get it before and I know pre oil those babies or youll fry them!! I seen my buddy do that he had a turbo coupe he gave it hell and just pulled up and shut it off without letting fresh oil run through it or something like that and locked up it was. So can I run nos with it? and what kinda cam?? or just standard my spec cam?? thank you all for telling me all of your opinions!!!! you all are awesome!!!
 

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turbo lag......yeeeeehaaaaaaw
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I would recomend a single pattern cam. The staggered cams dont make as much power (at least on supra motors). If you have a carb already I would sned it out to have it converted to a blow through style. You can run nitrous on turbo motors. It will spool a lot faster because they build more cylinder pressure. Its always a good idea to let your car idle for a couple minutes after a hard drive. If not the oil can clump in the turbo and cause it to run dry by clogging the feed and outlet lines.
 

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hehehe...so much info

Well, I have been there and done that a couple of times with turbo setups and I can tell you for sure you can do it cheap and make nice power gains. To start, I have seen a 302 block split completely in half due to turbocharging; split from the cam parting line down to the mains. 302 blocks are particularly weak, but you should be able to get 500HP reliably.

You don't need all forged internals, if you take it easy and keep RPM in check. Light weight forged pistons such as weisco, je, etc with recon. rods and good bolts will hold as much as your block will ;). Everyone gets caught up in the power levels comparing boosted engine power to NA engine power. Most internal engine failures are due to RPM rather than actual power output. Obviously, there is a point where this is not true, but for a pump gas low boost application you should be fine.

The Garrett T3's work very well on 302's and are widely available and sized perfectly for small cube small blocks. An HX35W from a 5.9 cummins would also work well if you want to go with a single. You would need a different wastegate actuator since those are about 22psi and that is not real pump gas friendly unless you want to do the water injection thing. I would suggest planning on 10-12 psi to start and get the bugs worked out. If you start trying to put up big numbers in that oe block you will have issues.

As for the cam, straight pattern cams can work. The real key is to keep the lsa in the 114 degree range. A typical 108 lsa hot N/A cam will not work well in a boost application. Summit Racing sells a couple of cam kits that work well and are very affordable. I think I gave $79 for cam and lifters....and they are made by crane from what I gather. That or crane mysteriously has identical cams in their parts book:D.

I am tired and rambling, but if you have any questions on turbo stuff feel free to ask.
 

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matts94sc said:
so where do i go to have the carb converted?
read this and then modify your 750 DP http://www.hangar18fabrication.com/blowthru.html

also, you will need to address fuel preassure, it needs to be refrenced to the boost, you can just drill out the fuel pump vent, epoxy in a brake line, and run it to boost preassure, or you could drill/ tap it for 1/8" NPT if you wanted, and run it to boost. or run a high preassure fuel pump, and a regulator with boost refrencing, and a return line.
 
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