Blow through carb set up
 

ok well i recently bought a rx7 and want to boost it...but im not sure if on going to use a turbo or not...if i do it will probably be a holset or larger t3..but as of now im looking into building a homemade supercharger kit...i was going to use and eaton m62 or m90 but i wasnt going to mount it to any part of the intake except for a charge pipe i was going to make a custom box underneath the the SC then have an air filter go where a TB would usually go....and that way i could run a IC and BOV on a roots or twin screw blower...and i have an electric fan to i could uses the bracket where the old fan was to run the SC i know it would work but the only thing im worried about is tuning...i dont plan on swapping the engine concidering it only has 60K on it...and i want to keep the carb..if anyone can explain to me how the blow through set up works or how to set it up it would help alot...iv been searching but never really found anything explaining it

Re: Blow through carb set up
 

good idea to search turbomustangs.com forum, they have aforum just for blow thru :y

Re: Blow through carb set up
 

Yeah, check out turbomustangs.com for sure. I'm doing a blow through on my car... Youre going to need at the very least..

rising rate fuel regulator (mallory makes a good cheapie, check summit)
high pressure fuel pump
carb bonnet
possible hobbs switches

I got a cold start injector off a 4Runner to spray little more fuel if it starts to lean out, at least thats the plan.

Depending on what the carb is like you might be able to use it as is, but you will have to see if the floats in it are crush proof or not.. If you cant use it I would probably use a small holley 1bbl off an old ford (easy to get jets for it) or a webber blow through carb (they conme up on e-gay every now and again)

Re: Blow through carb set up
 

nopistons.com

someone on there had one running for a while like a year ago or so i think.. it should be in the 2nd gen forums, i dont remember exactly who it was though

do a search there and you should find what ya need

Re: Blow through carb set up
 

thanks for the info..the boost will not be the problem im just new to carberator ..i never messeed with them before

Re: Blow through carb set up
 

http://www.hangar18fabrication.com/blowthru.html
A how to for setting up holley's for boost.

Re: Blow through carb set up
 

^^^^ thanks this helped me out a bit

Re: Blow through carb set up
 

The OE RX7 carbs are a knock off of a Holley i believe anyways but you might want to grab a Holley 4barrel and a adapter plate/intake manifold from Racing Beat or someone.I see carb hats of ebay all the time for $50-100 and Summit rules for carb fuel system parts :y

Re: Blow through carb set up
 

WOW you're getting lots of bad info my friend! Well in all honestly there are probably about 150 blowhrough FB's in the US. I'd say 140 of them blow through a weber. 5 on holleys and 2 on nikkis. I've got a FB with a S5 13BT blowing through a weber. I researched the supercharger thing for long time (2 years) and honestly none are efficiant enough to be honestly worth it in the end. Unless you go whipple. But then paying $6000 for just the charger you coud've allready had a 400whp turbo. My friend ran a Atkins 9" chager and at 14 psi with huge ports he put 210 to the wheels. Threw it away and now makes 350 @10 psi turbo. ---- on a stock S5 you will make 200rwhp @12psi. Most the info you seek will be better found on www.rx7club.com. Nopistons tends to be more FI and Big HP na related. As far as blowing through your Nikki. It's nothing like a Holley. They're way different carbs. So with that in mind yes you can run a Holley on your car, but you'll need the RB manifold too. If you just get a RB manifold any old carb won't just work. 4 barrel carbs are designed to have a constant flow drawn fron all 4 barrels even f 2 are closed. That's why you pay $600 for a $300 holley from RB they have to be modded just to run on a Rotary. As far as I know the only person to successfully boost prep a Nikki carb is Robert at www.rotaryshack.com noone is going to tell you how to do it because it's propietary info. But he can do it for you for a great price.
https://www.homemadeturbo.com/forum/...?topic=63704.0

Re: Blow through carb set up
 

^^^ this helped tons...but now my tranny is making some stupid noise so i ay need a new 1 :S

Re: Blow through carb set up
 

your totaly right ::) thats why direct freak made over 300HP boosted in his FB

your just an RX7club bitch

Re: Blow through carb set up
 

i kinda want to do a hmt set up...is their anyway i could set up my carbs for a blow through set up and make my own carb hat? im just curiouse

Re: Blow through carb set up
 

I ment big NATURALLY ASPIRATED HP group. Spend time in the engine building forum90% of the guya buid bridges and perry ports there. Rx7 club is the turbo spot. And Dude, Alex is a buddie of mine I've known him since 1999. He's using a different engine than we're talking about. He has a big dollar Cosmo 13b which has huge stock ports, and his is street ported beyond that. He has a very big dollar car. When he was running blow through he put 370 to the wheels @17psi. If you talk to him as I'm sure you naver have, his car was a bitch to drive blowing through the holley. He could never get it tuned right. Now that he's running a Haltech that put 490@17psi. So you can suck my dick! And directfreak as you know him had about 6000 posts on the club and aout 2000 on nopistons. Tell me where he prefers it. I've been building rotaries since before you had your licence. You can sure blow through a holley, but people are making higher HP numbers and have way better driveability on a weber. The problem is a Holley has to sit sideways on a rotary. Even with center hung float bowls the rear float bowl sill fills faster than the front and causes the rear to run super rich and the front to run lean. Second the holley has to have flow across all 4 chokes allways. and the way a rotary pulses and have to have devided manifolds holleys run like ----. RB modified ones make the carb merge so you can get flow across the whole carb, but it fucks up the velocity in the primanr andsecondary ports causing a shitty running car. You can just use an open hole space on any holley on a RB manifold, but it'll never run perfect. A weber has none of these probelms. Robert at Rotaryshack made 710rwhp on a blow through weber on a, are you ready? ON A 12A! Yea that's right... Enough said...

Re: Blow through carb set up
 

wow someone got his panties in a twist.. i didnt say ---- about 95% of that stuff yet you felt you had to come bitch about it all to prove me wrong, you obviously have no life, hurray for you!

i've done blow through setups, i never argued about anything you said, i simply gave the guy a place to gather info where someone had the setup he was talking about, and said you were wrong about NP being mainly NA power

btw the guy who had the SC setup was fluid dynamics if i remember right

good luck with your search, dont let this asshat change your mind on what you want to do because he has to have the bigger e-penis

Re: Blow through carb set up
 

im still not changing my mind...im not doing it for over all power or giant numbers..i just want to run a SC because its different and not to many people do it i want to do a set up like this

another hmt members SC build
Attachment 33297

or like this

Attachment 33298
Attachment 33299
Attachment 33300
Attachment 33301

Re: Blow through carb set up
 

Welp if supercharger is your goal. You need to get some maps and figure ou wha charger is coing to best fit your application. You'll need to figure out what carb your going to run, and what the max CFM of said carb is going to be and then you need to pick a charger for said application. In my research I found that a M62 was waaaaaayyyy too small. A m90 might work if you have modest power goals. By modest I mean 180 rwhp. Just look at the scoobie above he ran 2 m62's and choked up top cause the engine was pulling more air than the turbos could push. Now remember that your rotary is not a piston engine. And will out flow near every affordable supercharger above 6000 rpm. You will out flow a M90 if you're running a decent carb. If you go Whipple then you've got something that'll work great. If you want something bolt on try atkinsrotary, but know that even with theyr 9" charger on a built to ---- engine only made 210rwhp @14 psi. And the exact same engine with a turbo made 305rwhp @ 10 psi. The problem as stated before is that rotaries flow sooooo much air at high RPMS. It can be done, but noone has seen more than Dave with 210rwhp. Shoot Atkins own supercharged cars have yet to break 200whp. Most of that is cause the camden supercharger is the most ineficiant charer available. I hope you don't mind eshaft wear also.

Re: Blow through carb set up
 

no the problem as stated before is you dont like him doing an SC setup and are trying your best into scareing him into a turbo

he's stated he isnt shooting for big HP, he's going for something more original on an RX

turdbo, head over to NP and hit up fluid dynamics, he'll give you the skinny on a HMS setup for the 7

Re: Blow through carb set up
 

ya around 180 to 200 is what im shooting for and with the set up im running i also want to run a IC and BOV...i'll hit him up on nopistons.com and see what he has to say...remember its only a 12a and redlines at 7grand ..its not a 13b... im trying for maybe an m90 or m112 as long as it boosts the power and makes it a little funner to drive...but racing beat it very expensive...i think im going to send bmcrace some templated and have him make me an intake flange and carb flange and TIG up my own IM, 250 bux is a little crazy when i could make 1 for 100...and i come across superchargers rather cheap 150 for an m90...so the build shouldnt be bad at all...but i wonder how clutches hold up

Re: Blow through carb set up
 

what about edlebrok carbs???

Re: Blow through carb set up
 

Edlebrock carbs are usually ------ bore and there are currently not any manifolds available for them. If it's a edlebrock square bore manifold it should fit fine on the RB manifold. Remember if you're going to be using a carb on the RB manifold that was not RB prepped you HAVE to put on a open air spacer to get it to run right. Most any square bore carb( Holley, Carter, Edlebrock) will fit on a RB manifold with a spacer.https://www.edelbrock.com/automotive...mages/8710.jpg
something like that. No aftermarket carb will fit on the stock manifold with excpetion to the Sterling carb, whick is just a modded nikki, and he has yet to fully test any of his carbs in a boosted application. Sterling was tossing around the idea of supercharging on Rx7club a few years ago. There were a few 14 page arguements about it. Just search supercharger over there and you'll get pages and pages of links. If you're dead set on supercharging talk to people that have done it or have personal firends that had them. Talk to Codeblue and Codeblue2 on nopistons see what they tell you. Also talk to Sonicrat on rx7club he has had about 7 different supercharged 7's. And a 12a has the same issue as I was talking about. All rotaries had a 7k redline until 1989 S5 and up moved to 8k... Read for a few days and see what you think. That's what I did. An M90 should work that was my origional plan. But after years of research and hands on experiance with both setups I went Turbo. Superchargers are fun as hell boost nice and low in the rpms! Here's a link doing basicaly what you want to do, but it was on a s4 na car. It got locked for going way off topic, but it's a good read. http://www.rx7club.com/showthread.ph...t=supercharger
Here's another one for you. http://www.rx7club.com/search.php?searchid=2137689
And I'm not tryin to be an ass, or skew your view, just helping out a fellow rotard. I'd hate to see you spend hundreds of dollars and feel like you wasted your money.

Re: Blow through carb set up
 

no im dead stuck on a blower..not for giant hp gains..just enough to be rather quick ...im more of a road course person and have boost all the way through powerban is what i want i know a supercharger can pull it off..thanks for the threads and the suggestions

Re: Blow through carb set up
 

Hey man, sounds like you got a nice idea in your head. It's always good to find someone who wants to do something diffrent. Not sure if you need one...but I have a supercharger from a 3.6L buick laying around I paid like 70 beans for it at the junk yard.

Re: Blow through carb set up
 

m 90?...i might buy it off of you how about 100 shipped?

Re: Blow through carb set up
 

Remember with the m90 the inlet is on the back of the charger and since the 12a is so short and you've got that long ass nose on the charger setting it way back it's going to take some serious engineuity. Hope it all werks out. Have you decided what carb to blow through? I highly suggest a weber. It'll have better driveability and most everything needed to boost prep it is redily available.

Re: Blow through carb set up
 

ya im most likely going to buy a webber for sure ..i read their the best for a daily driver and the m90 he has i think has the short neck on it..but im still going to use it regardless..it will still fit

Re: Blow through carb set up
 

Cool if you go to rotaryshack for the carb and stuff tell robert I sent you and hell hook you up on price. Also If you're i WA I can isntall it for you. I'm cheap too.

Re: Blow through carb set up
 

I ran a turbo weber setup for about 3 monthes of racing. It made power and was kind of neat. 200 to the wheels with a small ass turbo and a ew1 1.5

Randy

Re: Blow through carb set up
 

sounds cool...im still stck on the webber and sc but right now i need a new radiator

Re: Blow through carb set up
 

ha!!! I helped with the black L28 engine. Nice to see it inspire others.

Bernard

Re: Blow through carb set up
 

ya i also own a 75 280z...i like oldschool jap cars hahah but i need this carb thing worked out