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-   -   my n/a supercharging project complete (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/my-n-supercharging-project-complete-289791/)

poor_red_neck 04-06-04 01:22 AM

Also, this is going to help the low-end torque ALOT.

The fact of not having to modify the exaust at all.
No messing with routing coolant lines.
No messing with oil lines.


This is MUCH easier.

The hardest part of this install, would be installing an S-AFC, and the mounting bracket.

Since zbrown has done the hard part of making the bracket and getting everything sized/lined up... if you could just re-create his bracket, sell them fuckers... you'd GURANTEE to sell some.

Hell, this could be a big canidate for a complete supercharging kit. Pre-made piping and everything.

Anybody up for the challenge?? :)

If I had the cash, I'd make a few kits... buy some superchargers, polish em up, get some mandrel bent pipes.

Ah well....


-Jon

RETed 04-06-04 01:25 AM


Originally posted by rotarygod
I don't see any way that this isn't the best upgrade for the money.
NOS is better bang for the buck.


-Ted

SonicRaT 04-06-04 01:28 AM

Cost of turboing my N/A, under $300, minus fuel (since it wasn't included in this thread) They both can be done for a fairly equal ammount of work/money.

Dakmis 04-06-04 01:29 AM


Originally posted by RETed
NOS is better bang for the buck.


-Ted

doesn't this harm the engine more though?

neptuneRX 04-06-04 01:40 AM

I'll look into S/C later. I need to focus on my upcoming rebuild first. See how everything turns out then proceed to SC

rotarygod 04-06-04 01:45 AM


Originally posted by RETed
NOS is better bang for the buck.


-Ted

Only if you never have to pay to refill the bottle. That adds up pretty quick and is only good for a short time. This is an advantage every time you drive the car and it won't run out when you want it the most. Still the best bang for the buck.

FC3S-NovaStyle 04-06-04 02:37 AM

i preffer s/c over nos.. and i sometime prefer turbo over s/c but in this case "you're broke and your want power what you do, seek out the cheapest power adder".. get me the shape of the bracket and the material you use i'll make some bracket.. too much free time on my hand not gurantee on piping tho.. that your own preference.

scathcart 04-06-04 03:18 AM


Originally posted by rotarygod
An Eaton supercharger does not need any water or oil lines plumbed into it. That in itself is much less work. The stock T-II exhaust housing is so pathetic from a flow standpoint that there is alot of loss through it when you could be getting a gain from a good set of headers instead. It takes a T-II a couple of psi of boost just to get back to equal power of no turbo. That sounds like parasitic loss to me.

Yes turbo upgrades are easier. I will concede to that. This is just far less work. A T-II turbo would also need a new downpipe made and a spacer to make it clear the lower intake manifold. No more emissions control or 6 port actuators either. I don't see any way that this isn't the best upgrade for the money. There was never any claim that it had the most potential of any mod.

Oil and water lines are simple plumbing, and the exhaust piping is no more complicated that the piping adapters shown here.
As for power loss... how much of the difference in power can be attributed to the differences in intake ports, lower compression, and intake manifold design? IE: throw N/A stock exhaust onto a 4 port turbo engine, dyno it, and see what the horsepower is. It won't be anything close to the N/A HP values, due to the listed factors.
Turbochargers house a more efficient compressor than the eaton unit. Overall, I think the only benefit of this s/c is the low-end boost.

scathcart 04-06-04 03:23 AM


Originally posted by Dakmis
doesn't this harm the engine more though?
No, not at all.

scathcart 04-06-04 03:24 AM


Originally posted by poor_red_neck
Also, this is going to help the low-end torque ALOT.

And run out of steam big time on the top-end...

NZConvertible 04-06-04 05:10 AM


Originally posted by poor_red_neck
The fact of not having to modify the exaust at all.
If you think an exhaust suitable for an NA motor is going to be just as suitable for a supercharged one then you're very wrong. Increasing the engine's airflow by 30-50% will always require a bigger exhaust, otherwise you're just strangling it.

Those who think this is a cheaper way of getting turbo power levels are kidding themselves.

wozzoom 04-06-04 08:07 AM


Originally posted by scathcart
And run out of steam big time on the top-end...
A SC is very linear in output.

http://www.automotive.eaton.com/prod...trols/M90.html

The Eaton M90 tops out at 525 CFM at 12,000 RPM. to determine if the SC will run out of steam "big time", you would have to know how many CFM a 13B moves at 8000 RPM?

How does the stock turbo compare?

wozzoom 04-06-04 08:24 AM

zbrown:

I have a very big question for you...Is there any way you could measure the TEMPERATURE of the air coming out of the SC?

I'm trying to determine if this SC needs to be intercooled. From the Eaton website: at 5lbs of boost, the M90 can raise the intake temps about 50 degrees. If this is the case, you could easily see intake temps around 180-200 degrees F. Is this safe???

DEZERTE 04-06-04 09:32 AM


Originally posted by NZConvertible
If you think an exhaust suitable for an NA motor is going to be just as suitable for a supercharged one then you're very wrong. Increasing the engine's airflow by 30-50% will always require a bigger exhaust, otherwise you're just strangling it.

Those who think this is a cheaper way of getting turbo power levels are kidding themselves.

i dont think anybody thinks they are getting turbo power by doing this, obviously you will need a larger exhaust if their going forced induction. I think he was referring to the manifold in not modifying the exhaust.

monkey 04-06-04 10:15 AM

Ok, I recently bought a 86 N/A and am new to the whole RX7 scene. I've spent the last 3 days looking into every aspect of this build up!!! and it seems like a great idea for me because i already have a T-Bird S/C, but my BIGGEST QUESTION is how or if you can retard timing on these engines. With 7-8psi of boost on a car with 9.4:1 (mine, i think zbrown's is higher) your talking a C/R of around 13.5:1. Thats bad news. I really want to do this but without adjustable timing its most likely going to blow. If im missing something please tell me because im looking for all the information i can get and like i said, Im new to the 7's

Tofuball 04-06-04 12:38 PM

Allright, my biggest question, what does fuel economy look like now? :)

I'm seeing 18 city right now, without a supercharger.

What would I see with one? 12? :-p

I doubt it would affect highway that much tho.

Phu5ion 04-06-04 12:41 PM


Originally posted by wozzoom
The Eaton M90 tops out at 525 CFM at 12,000 RPM. to determine if the SC will run out of steam "big time", you would have to know how many CFM a 13B moves at 8000 RPM?
Let me refer you to yesterday. Again, feel free to check my numbers.

Originally posted by Phu5ion
I have wondered about that but never really got into it. Here is some information from Eaton's website about the M90.

Their website says it will flow over 500 CFM at redline. I did a quick calculation (anybody feel free to check me on this) and a S5 motor at 8000 RPM "should" move about 370 CFM.


Chimeron 04-06-04 12:53 PM

Ok, I may be called an idiot for this, but can someone explain the bypass valve to me? I don't know too much about forced induction right now but I'm trying to learn and this sounds like a good project so can someone explain how the bypass valve piping is run? And what TYPE of valve he used?

Atticus 04-06-04 01:02 PM


Originally posted by RETed
NOS is better bang for the buck.


-Ted

http://pages.moparpages.com/gtsdart340/pics/nitrous.jpg

:p: Someone had to do it! :D

FASTRAKR 04-06-04 01:20 PM

its called nitrous, but shortened to nos because it stands for Nitrous Oxide Systems.

poor_red_neck 04-06-04 01:30 PM


Originally posted by FASTRAKR
its called nitrous, but shortened to nos because it stands for Nitrous Oxide Systems.
"NOS" is a brand by Holley.

greenchili 04-06-04 01:32 PM



If I had the cash, I'd make a few kits... buy some superchargers, polish em up, get some mandrel bent pipes.

Ah well....


-Jon [/B]
zbrown has a huge opportunity to make some capital for such a project if he did a write up and quit track!

don't quit track....i'm j/k

poor_red_neck 04-06-04 01:36 PM


Originally posted by greenchili
zbrown has a huge opportunity to make some capital for such a project if he did a write up and quit track!

don't quit track....i'm j/k

Yep.

If somebody could make and sell these support brackets for the supercharger... you'd be in business right there.

For say... 50 bucks? I'd buy one right now. I dunno... how much for just a 1/4" steel bracket? Don't have to be "bling bling" and shiny with PERFECT welds or ...

I'm not looking for show under the hood. As long as it goes. :)

DEZERTE 04-06-04 01:57 PM


Originally posted by poor_red_neck
Yep.

If somebody could make and sell these support brackets for the supercharger... you'd be in business right there.

For say... 50 bucks? I'd buy one right now. I dunno... how much for just a 1/4" steel bracket? Don't have to be "bling bling" and shiny with PERFECT welds or ...

I'm not looking for show under the hood. As long as it goes. :)

werd, somebody could make a fat profit here, I wouldnt mind making my own just for the experience of doing it. But hell, id buy one if they were offered. My 2c's

Bauer778 04-06-04 01:57 PM

Yea i was thinkgin of the same thing is someone could make those brackets, they could make a killing, i would defintly buy one.


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