here the m90's sc are about $300 tops second hand.. and to do the turbo swap is average about $4000.. that huge difference.

bypass valve
 

what is that bypass valve from? what car please tell me.... im almost there

That "bypass valve" looks suspiciously like my $20 bosch BOV I have.. from either a saab, mitsubishi, volvo... etc..etc..

where can i get that bypass valve from? for 20 bux?

Ebay is always a good bet for anything

who here is actually going to do this? im going to the junkyard tomorrow to pull myself a eaton m90 supercharger , my friend owns a yard and sait 100 bux if I pull it....cant beat that with a stick! ill be hunting this week, just not for eggs!

You quoted my post but didn't appear to read it. I never they wouldn't work, I said they would be restrictive. RB headers are designed for naturally-aspirated engines, not supercharged ones. More powerful engines needs bigger pipes or their power will be restricted by the exhaust. It's a pretty simple concept.

I assume you mean the auxiliary ports. Wiring open the secondary throttles would be a very bad thing...

So if I weld my own custom exhaust as true duals as 2 inch each I should be ok? Including the header. But when I think about it, the racing beat racing header is 2 inches, so i should make one 2.5inches?

Maybe I could make it 2 inches as a true dual because people here were referring to a collected system???

anyways, it's fun to think about, and great job on the supercharging man!...later:)

Re: sc question
 

Smaller SC pulley = more SC boost


-Ted

other things
 

Man i really appreciate your input on this thread. If you don't mind and have the time, I would really like to hear what else should be considered. I realize that this can end up a disaster if you take the wrong things for granted!

Dave

wow... very nice

So can someone answer my questions? The air bypass is recylcing the air back into the intake before the charger right? And the tube coming off the back of it goes where? Is it a calibration tube so that it knows when to let air through?

Yes, thats exactly what I did.

Come on guys, stop arguing about reading each others posts and give some real answers. I know you guys are knowledgable enough.

I finally got ahold of and eaton 90

sweet let us know how it goes. dezerte..

Basically the bypass is just like a BOV, and since it's recycling air that's already been metered (at idle, not decel), it has to be routed back to the intake (before the supercharger, otherwise you'll have pressure on both sides. It differs from a BOV in the sense that it is open even at idle, since your plates are too closed, but the supercharger is still spinning fast enough to create boost. This is done by either a vacuum line to open it (it should NEVER see boost, only vacuum), or too much boost pressing on the valve. Now a blow off valve will help alleviate the high RPM shifts where the bypass valve is overworked. I hope this helps.

Thank you very much sonic, That's what I thought, I just wasn't sure. Where would the vac line be run to get vacuum at the right time?

stock TII has a bypass valve.. would probably work fine for this.

pat

If this is not an April Fools joke then I hand it to ya. Good job for a 19 year old. Nice welds too... Give us more details and pic and let us know how it all works out. I AM IMPRESSED!!!

This is going to be an awesome project... when he said he was going to install a blowoff valve, does he mean hes going to have a blowoff valve AND A bypass valve?

Yeah, the bypass valve can't relieve all the pressure at high rpms so he is putting in a BOV to relieve the extra pressure.

Anything after the throttle plates should see vacuum at idle, since it can't suck in the air (due to the fact that they're closed) This should allow the valve to open, however there's always some air that escapes, wether or not this overcomes the total ammount of vacuum, I can not tell you. But that's how it should be setup. For those of you who asked prior if he was going to use a BOV and a bypass, he said this is what he was planning on doing, as the bypass couldn't relieve enough pressure at high rpm/load.

Please be aware that the BOV and bypass valve are not set up the correct way.

They do work but they are used to save money by not having to relocate the throttle body.

The correct way would be to have the SC suck through the throttle. A bypass valve in this setup would be nice but not strictly necessary. A BOV would not be necessary at all because a roots style SC has constant boost.

However the correct way is more complicated and more expensive. This incorrect setup does work but he is running into some problems with not being able to bypass enough air so he needs two of them.

ed

I might be wrong but I haven't looked down the throat of my throttle bodies lately.

You can wire the vacuum operated throttles open but you must leave the throttle linkage operated throttle plates alone.

A lot of ITS racers remove those throttle shafts completely.

Maybe I have the naming convention confused?

ed

This is commonly called the 'throttle body mod', in which the vacuum operated plates are removed comletely, and the holes are tapped/plugged. When most people mention wiring ports, they are talking about the auxilary 5th and 6th ports that open at 3800rpm (and, considering that the vacuum operated throttle plates are only closed under vacuum and are spring loaded to stay open, there's not much sense in wiring them when you can just cap the line that runs to them) But regardless, I believe that is what he assumed you were talking about.

hey guys, i got my blow off valve on yesterday and everything works perfectly, no belt slippage at all. The valve blows off perfectly how i wanted it to, stays closed durning idle and cruising and only blows off at shifts above 3000rpm and when i am down shifting. If it is in neutral and i rev it up to like 5000rpm and let off it is very loud. it sounds great. I will get some pics of it on, also on the camera i use i can make a 15 second movie on a single floppy disk. Is there any way i could get it loaded on this site or hosted by someone. I would take a short movie so you all can here how it sounds and see the s/c in action.
sorry i dont have much time, I am not trying to blue ball you guys or anything i just dont have much time to get on
let me know about the movie thing
gotta go bell rang

I thought the 5/6 ports on the S4 were default closed? This would mean if you just caped the line they would stay CLOSED, very bad for performance.

You fucking own all Zbrown. Would love pics of your new setup and movie would be great, i will keep checking :D

Hell yeah, if that camera of yours can take movies get one of it running and revving a few times. Sound would be a HUGE plus.

I can host just about anything. Email it to me, rat@sonicrat.org

I was refering to the secondary vacuum controlled throttle plates, on the throttle body.

oh, hehe. Sorry. i thought you were saying you didn't see why people wire the 5/6 ports open when you can just plug the vac line.

So how was nitrous a better bang for the buck again? Doesn't everything else also apply to it too? You're right HE paid $300. I could personally do it for that much or cheaper too. I do have T-II injectors lying around. I even have an entire spare T-II drivetrain sitting here. I can weld. I do have access to free materials. I also have a built car and don't need to do this though. You don't HAVE to do anything you mentioned to get a GAIN. You have to though to get a BIG gain. I won't deny that. Show me one intake or exhaust that will give you such an improvement for that little amount of money. Even a small amount of nitrous will be fine. Yes it is an eBay transaction. He may have actually gotten it cheaper or he could have gotten screwed over. It can happen. Invalid excuse. He didn't!

It still stands that this IS the best bang for the buck. Everything else is an excuse. Like I said, no one denies that there aren't ways to improve this for more money. He has been more inspiration than we have seen from any others here in a long time. If he listed to all the excuse makers so called logic, he probably wouldn't have anything done to his car at all right now and he also wouldn't have anything original.

Way to go Zbrown! Keep the pictures and hopefully a video coming.

yea , a vid would be sweet

This and a turbo can be done for the same price, so they're both about equal :)

heres some pics of the blowoff valve, i am sending the short clip to SonicRat so he can post it. not the best quality sorry

here is another, Ill try to get a better movie to
zac

I still don't get why your running two BOV's...?

Or am I missing something very obvious.......

Hes running a bypass valve to recycle the excess air back into the intake but it doesnt relieve enough of the pressure, hence the Blow off Valve.

i wonder if it is even remotly possible to supercharge a turbo....they said you couldnt super charge an NA......hmmmm

Who said "You can't supercharge an N/A."??

The morons.

somebody get zbrown a computer for the love of god I can't stand the suspense of waiting for his replies every day!

Sorry it took so long, was out running 1/4 miles with the GTUs, here is his video.

http://www.sonicrat.org/na-sc.mpg

sweet:drool:

:drool: :drool: :drool: :drool:
That video is better than porn of young young girls.

omg that is intense. you are so rad. you have given hope to anyone who ever owns a n/a rx-7. write up is definately needed. very detailed. so the most simple minded when it comes to cars (me) can do it.

well it's simple as like a bolt on i'll say from lookin at it.. just have to know some basic mechanic to work around the car. what i need it that bracket, and mounts..
parts in mind would be right for this setup:
turbo II fuel pump
turbo 550cc injectors
turbo II fuel rail need or could work around with aftermarket fuel regulator anyways
s-afc

Sort of. Both pairs of throttles in each bore are technically "secondary" throttles, because they control the secondary ports. Mazda refer to the upsteam pair as the #2 secondary throttles, and these are removed as part of the TB mod. The primary throttle (the single one that opens first) controls the primary ports. :)