Study hall must be really boring for you to think up a SC for the Rx7:D. Good job man. I am in high school too so I understand study hall is nothing but think time. Keep the work up.

-Derek

I have to go class is over. my full size pics too big so i will have to take them over again on a lower quality. ill post them after school

Good job dood..........w rite up is a MUST for this thread.

i had a free day in Chem. so i took some more pics

1

this is where i am going to put the blowoff valve

another

here is a pic of how much vac i have at idle, ill get a pic of it boosting low in the rpm. I know I know my dash is filthy

another

you must do a write up of step to step of how you did this or we will hunt you down and interrogate you and get the info from you. ALL YOUR WRITE UP ARE BELONG TO US.

last one for now,

I have a question for all of you guys, right now i am running with the 5/6th ports tied open and the vdi closed. Will i have better flow with the vdi open or closed. Would it be worth it to make the 5/6th ports operational with the manifold boost. I have a rpm switch to control them and also for the vdi operational or not? Give me any input on this please

What did you do about belt tension? It looks like the idler pulley is stationary

their is a slot for the idler to slide up and down up close to 3",

Wow.

Just... wow.


I am in utter aww. :D

That looks FANTASTIC!

I didn't catch this... but did you upgrade injectors? I have a S-AFCII as well, but still the stock N/A injectors and pump.

I wonder if upgrading to TII injectors and pump would be sufficient?

I would keep the VDI open... since during low RPMs you will have enough air flow to make the VDI efficient.

Wire the VDI open once and see how it goes, as far as I am aware by design it opens up two shorter paths, and as it looks it leaves the others alone.

Re: keep this alive
 

He could bring it to the Revolution and prove it's for real ;)

Hmm. Anybody want to try low-comp rotors and twin charging with a big-ass turbo?

I still have stock injectors and pump. I have a a/f gauge and so i can keep an eye on it(it no wide band i know) Ionly have my fuel levels turned upslightly like three notches past neautral and my gauge reads perfectly where i want it. I have not had one ping and i am running89 octane. I am going to have it dyno tuned shortly, Ill wire the vdi open once and see how it goes. I cant wait to get my blow off valve so that i get the sound that i have always wanted too, I should have that on by next friday

where did you get the idler pully from?? and hoses? and finally the afr guage(looks to be a pep boys one i think)

Impressive ! :D

Damn.... Just... Damn...

Make and kit, atkins will never sell their s/c with pricing like yours :p:

What are you doing as far as retarding timing under boost? Also, where did you get the bypass valve, and the idler pulley??


Thanks,
Justin

Correct me if I'm wrong but I thought blow off valves were for turbo cars. Superchargers don't suffer from backpressure issues that turbos do because the pressure is metered by the engine speed.

My friend is about to revitalize his old RX7 to start racing it in local SCCA races. He pointed me to this thread. I used to own an 87 turbo myself and miss my rotary rocket!

seriously, not to give you any ides, but i would gladly pay money for a step by step writeup of this. GLADLY. ill do this if thats what it comes down to :D nice work man, thats so insane.

wow dude... very impressive

No kidding, for about what 400 and some welding, damn! That is some nice work. I know if more people do it, its only going to get better. Crap can anyone lend me 400 dollars?

Nice.

Of course some one figures out a cheap way to do it after I get my turbo conversion almost done ;)

Mad Max come to mind - a little crude, but very effective.

here are some answers to some questions you guys had

The m90 is off of a t-bird, the m-90 from a grand prix has part of the intake cast onto the s/c and it is way too big

The engine pad i am talking looks something like this
red-the actual bracket coming from the engine(made out or aluminum
black-the actual round (steel) pad that sits on a rubber stub or like a pilliar
blue-is the bolt attaching the pad to the engine bracket
brown- is a peice of 3/8" steel i welded to the pad, the rest of the upper bracket is welded to this peice
green- is where i welded on the backside of the pad , in the crease where the pad and steel peice meet
yellow- yellow is where i welded on top of the pad

does this pic help at all?

The pulley i had machined at a place where they rebuild electric motors. I went there because since the s/c has a straight shaft just like electric motors and not a tapered one i figured he could set me up with some thing. All he had to do was drill the shaft hole out slightly and cut a different sized key into a pulley he had on hand.

The piping and clamps and elbows came from a local filter shop for little to nothing

ok, usually superchargers are placed after the throttle plates(like a picture shown on like page 6 of this thread), but i put mine before it(alot less fabing), Most cyntrifugal s/c's are piped like mine and use a bypass valve.

u need a bypass valve because when u shift , or even at idle the bypass valve opens because the throttle plates are blocking the air flow and a huge boost spike is created, The bypass valve is opened either by vacuum(when the engine is at idle) or when too much boost is created and and the excess pressure pushes open the valves plunger(shifting)

At first i just wanted to use an open atmoshere blowoff valve but that would screw up my computer since it is mass air metered and at idle it would vent air to the atmosphere and not recycle it back into the system.

The one bypass valve i have cant vent the excess pressure fast enough at high rpm shifts but it works perfect at idle. I plan to hook up the blow off valve i ordered with out the vacuum line attached to it so that it will only open when too much pressure is present and not at idle. If i cant get the blow off valve to work properly ill just buy another bypass valve and hook it up just like the one i have on it right now, i know two would be more than sufficient.

I got the bypass valve for $12 shipped to my place off of ebay

As for timing i am not worring about it since i havnt had any predetination

I found the idler at my place, it is a peice of shit and an eye soar, so i have a nice new smaller one on the way

i am seriously jealous

Damn only if we all had as much talent as you, RX7s would be the fastest, cheapest cars on earth!!!!

Not bad but it looks like there's no space..
Turbo would be my choice but supercharger must be tons of fun too..Probably a little more reliable also..
Good luck..

^ Ditto :D

This is not true, the air still travels the longer path, the valve just opens a shorter acoustic path for the pressure waves to travel down, opening it will just loose low end super charged or not.

The idea was to acheive as much flow as possible, I didn't comment regarding this as a perm solution, I gathered from what he said that he'd like to know if it'd help at all opening (which can still be done, just use the solenoid with a feed from the intake, the boost will be more than sufficient to open it, (however you're going to want to devise a bypass so it won't blow the poor thing apart!) But, thanks for commenting, tells me I should be more clear with what I'm stating.

here you go here is your proof

one more

:drool:

...sweet...

I'd pay for a write-up if that what it takes. Helps that you have the same year and model as me...

Kay Dude Mad Props.. I hope u get some good numbers and just fukin piss in anyones face that says any shit to you... ur the man

hey yo man you want me to send you some money to fill up ur tank.. ! and send me a copy on how to do this!

I'd LOVE to see what this puppy does on a dyno for inclusion on my dyno page:

http://www.catenet.net/dyno.php

Very well done man. Would love to see some dyno numbers myself. Must be a blast to drive a SC'd NA! :D

Good luck, keep info coming.

later
-Justin

or just get respected and do the write up with pictures to help people out......."pay for a write up".....wtf

WRITE UP WRITE UP WRITE UP!!!!

PLEASE!!!

great job dude. i was gonna do this almost exactly to my na i had in high school, but i couldnt find the t-bird sc cheap enough, then i had a little incident with a tree...glad to see i wasnt the only one with this idea..whish i could ride in it and see how i would have been...

oh well..i just built a high comp TII..which is kinda similar.

oh yeah...you might wanna switch to a serpentine belt setup. you should be able to find pulleys for everything except the waterpump at a good junkyard. the waterpump you'll have to get custom made, tho. should make it all a lot simpler and more reliable/less slippage.

i had a couple more suggestions, but i totally forgot em...oh well

ps..all you writeup people...why? he has explained it really well, and what he has done is very simple when it comes down to it. part of the coolness of shit like this is that it takes someone with a bit of ingenuity like zach to do it. if you cant figure it out from whathe has told you already, maybe itd be better for you to not do it. takes away from the prestige of the real engineers that figure stuff out for themselves.

just my .02
pat

All I have to say is that i'm insanely impressed with your
inginuety and fabbing skills, this is definetly on my to do list when I get the time. You have to try to take some better pics or draw up something more clear to describe how you mounted it etc... MUCH PROPS MAN!!!

If you make a good good writeup ill donate to you via paypal even if its free!

omfg
$300 supercharge rx-7 sweet jesus

how long did the whole project took you ?