2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.

supercharged rx7?

Thread Tools
 
Search this Thread
 
Old Mar 23, 2011 | 09:55 PM
  #1  
aimfabrication's Avatar
Thread Starter
newbie wanting to learn!
 
Joined: Feb 2011
Posts: 16
Likes: 0
From: santee
Talking supercharged rx7?

has anyone ever done/ thought about taking the supercharger off of a mk1 mr2 and rigging it up to a 13b?
Reply
Old Mar 23, 2011 | 10:40 PM
  #2  
SirCygnus's Avatar
whats going on?
Tenured Member 20 Years
iTrader: (1)
 
Joined: Mar 2004
Posts: 4,930
Likes: 8
From: atlanta ga
heh. you assume a 1.8 liter engine breathes the same as a 2.6 liter engine. lol
Reply
Old Mar 23, 2011 | 10:47 PM
  #3  
K-Tune's Avatar
FD Daily
Tenured Member: 20 Years
iTrader: (27)
 
Joined: Jul 2003
Posts: 3,308
Likes: 14
From: Gulf Breeze, FL
it's actually a 1.6 liter motor in the mr-2...and it only makes around 150hp with that supercharger.


you'd need 3 or 4 of those little things.
Reply
Old Mar 23, 2011 | 11:08 PM
  #4  
Derekcat's Avatar
Rotary Zealot!
Tenured Member: 20 Years
iTrader: (8)
 
Joined: Jun 2004
Posts: 1,736
Likes: 2
From: Milwaukie, Or
Originally Posted by K-Tune
you'd need 3 or 4 of those little things.
That would be hilarious!

And for the OP: http://www.CamdenSuperChargers.com/
If you really want to..
Reply
Old Mar 23, 2011 | 11:17 PM
  #5  
aimfabrication's Avatar
Thread Starter
newbie wanting to learn!
 
Joined: Feb 2011
Posts: 16
Likes: 0
From: santee
well im trying to figure out an way to make my car more fun (torquier/faster) that is soft on my wallet....any opinions then?
Reply
Old Mar 23, 2011 | 11:18 PM
  #6  
aimfabrication's Avatar
Thread Starter
newbie wanting to learn!
 
Joined: Feb 2011
Posts: 16
Likes: 0
From: santee
oh and that supercharger is sick but...to much mula for me...
Reply
Old Mar 23, 2011 | 11:45 PM
  #7  
canonize-ryda's Avatar
Senior Member
 
Joined: Mar 2010
Posts: 623
Likes: 0
From: wyoming
port it
Reply
Old Mar 24, 2011 | 12:00 AM
  #8  
JustJeff's Avatar
Apex Seal Treachery!!!!!!
Tenured Member 15 Years
iTrader: (13)
 
Joined: Nov 2006
Posts: 2,406
Likes: 2
From: Indiana
Originally Posted by aimfabrication
well im trying to figure out an way to make my car more fun (torquier/faster) that is soft on my wallet....any opinions then?
torquier and soft on wallet don't go hand in hand
Reply
Old Mar 24, 2011 | 01:18 AM
  #9  
Derekcat's Avatar
Rotary Zealot!
Tenured Member: 20 Years
iTrader: (8)
 
Joined: Jun 2004
Posts: 1,736
Likes: 2
From: Milwaukie, Or
http://www.racingbeat.com/RX7-1986-1...sts/16420.html
Felt a little bit torquier to me [I had RB header/presilencer and a good condition stock catback, switched to this]
Usually this catback goes for ~$300 used. [If you can find one]

I'm not sure about torque, but I was told by an older guy who races FBs with his son, that a light flywheel will make a big difference in how the car feels.

..Other than those - get suspension and go fast around the corners ^_-
Reply
Old Mar 24, 2011 | 05:56 AM
  #10  
Evil Aviator's Avatar
Rotorhead
Tenured Member 15 Years
 
Joined: Feb 2001
Posts: 9,136
Likes: 39
From: Charlottesville, Virginia, USA
Originally Posted by aimfabrication
well im trying to figure out an way to make my car more fun (torquier/faster) that is soft on my wallet....any opinions then?
Well, porting is cheap, but it decreases low-end torque in order to increase high-end torque. If you want to maintain low-end torque and see an incease in high-end torque for a low price:

A. Sell your car and buy a Turbo II.
B. Assuming they are still available after the disaster, a J-Spec engine conversion is the next cheapest way to make more torque.

Contrary to popular belief:
- Turbos make torque.
- Turbos are a type of supercharger ("turbo" is short for the word "turbosupercharger").
- Belt-driven superchargers tend to be rather complicated and expensive.

Originally Posted by Derekcat
I'm not sure about torque, but I was told by an older guy who races FBs with his son, that a light flywheel will make a big difference in how the car feels.
A light flywheel will make the car feel like it has less torque on a standing start.
Reply
Old Mar 24, 2011 | 07:20 AM
  #11  
tuscanidream's Avatar
T2 Duo!
iTrader: (6)
 
Joined: Oct 2010
Posts: 1,665
Likes: 3
From: RI/CT
There has been an FC for sale on craigslist in my area for years. It is an unfinished supercharger project. No idea what happened, but he didn't finish it and no one will buy it. And he is selling it cheap. While I don't know the details, supercharging may not be the way to go.

As stated before, best bang for buck would be a T2 swap. Or stay na and port with exhaust, flywheel and tuning.

If I had an na, I'd go carb and clean up the rats nests. Don't be hatin. I love carbs. All 4 of them seem to work excellent on my ninja!
Reply
Old Mar 24, 2011 | 07:04 PM
  #12  
Syritis's Avatar
Can Post Only in New Member Section
iTrader: (2)
 
Joined: Jul 2004
Posts: 930
Likes: 0
From: Calgary, Canada
you might wanna look into this thread
https://www.rx7club.com/1st-generation-specific-1979-1985-18/camden-dyno-pull-924013/
Reply
Old Mar 24, 2011 | 07:39 PM
  #13  
blackrotary23's Avatar
snap crackle brap
Tenured Member 05 Years
 
Joined: Dec 2007
Posts: 536
Likes: 0
From: indianapolis, indiana
you can do what i did. but not make the same mistakes, lol.

i took a stock n/a block and ported the lower intake of a TII to match the ports on my 6 port motor and pretty much transferred all TII parts into my car......i mean everything. i used a chipped ecu with an added 40 hp and cranked the boost up to 16 lbs with a manual boost controller. just make sure you use the correct TII wire harness for your series car (s4/s5).

aaron cake has a great tutorial about how to do this without using TII parts:

http://aaroncake.net/RX-7/projecttina/index.html
Reply
Old Mar 24, 2011 | 07:55 PM
  #14  
-Crash-'s Avatar
89FC
 
Joined: Mar 2010
Posts: 545
Likes: 0
From: Bay Area, Cali.
Karack is fabbing up a mount for an Eaton M90, thread is in the 2nd gen forum somewhere.
Reply
Old Mar 24, 2011 | 10:13 PM
  #15  
Syritis's Avatar
Can Post Only in New Member Section
iTrader: (2)
 
Joined: Jul 2004
Posts: 930
Likes: 0
From: Calgary, Canada
Originally Posted by -Crash-
Karack is fabbing up a mount for an Eaton M90, thread is in the 2nd gen forum somewhere.
it's in the fabrication forum

here
https://www.rx7club.com/fabrication-250/13b-supercharger-manifold-934766/
Reply
Old Mar 24, 2011 | 11:03 PM
  #16  
Derekcat's Avatar
Rotary Zealot!
Tenured Member: 20 Years
iTrader: (8)
 
Joined: Jun 2004
Posts: 1,736
Likes: 2
From: Milwaukie, Or
Originally Posted by Evil Aviator
A light flywheel will make the car feel like it has less torque on a standing start.
>_< Sorry, brain fail... Somehow I forgot about that..
Indeed, it will feel less torque-ie off the line.. What I was thinking was that it might feel more torque-ie after it was rolling - is that correct?
Reply
Old Mar 24, 2011 | 11:36 PM
  #17  
BurritoBut's Avatar
Full Member
Tenured Member 10 Years
 
Joined: Jan 2009
Posts: 152
Likes: 0
From: Auckland, New Zealand
Friend of mine has a blown supercharged s4 turbo motor in a rx4.
I think there are videos online, it's green and the number plate from memory is DABUZZ.
Reply
Old Mar 25, 2011 | 05:40 PM
  #18  
Syritis's Avatar
Can Post Only in New Member Section
iTrader: (2)
 
Joined: Jul 2004
Posts: 930
Likes: 0
From: Calgary, Canada
Originally Posted by 90VERT
I would think that a turbo is prefered over a supercharger in most cases.
if i was given the choice, turbo or S/C for daily driving i'd hands down pick the S/C, for peak HP or track use i'd stay with a turbo.

S/C power band are linear
turbo power bands are exponential.
Reply
Old Mar 25, 2011 | 06:44 PM
  #19  
Evil Aviator's Avatar
Rotorhead
Tenured Member 15 Years
 
Joined: Feb 2001
Posts: 9,136
Likes: 39
From: Charlottesville, Virginia, USA
Originally Posted by Derekcat
>_< Sorry, brain fail... Somehow I forgot about that..
Indeed, it will feel less torque-ie off the line.. What I was thinking was that it might feel more torque-ie after it was rolling - is that correct?
It depends on the situation. A flywheel soaks up energy when the engine is accelerating, and then discharges that energy when the engine decelerates. With a "light" flywheel, those who usually accelerate from a stop by simply mashing on the gas pedal will feel the engine (and car) accelerate quicker, but the effect usually feels more like additional horsepower than it does like more torque. Those who usually accelerate from a stop by revving up the engine in neutral and popping the clutch will not feel the "light" flywheel transfer nearly as much energy as a "heavy" flywheel, and the engine will feel like it has less torque.

* I use the term "light" and "heavy" in quotes because it is actually the inertia that affects the feel of the flywheel. The inertia is affected by both the static weight and the weight distribution, so with the proper design it is actually possible to have a heavier flywheel with less inertia than a lighter flywheel. Therefore, the flywheel terms of "light" and "heavy" are actually misnomers.

Originally Posted by Syritis
S/C power band are linear
turbo power bands are exponential.
Turbosupercharger and centrifugal supercharger power bands tend to be more exponential. A typical Roots power band is fairly linear until it runs out of steam and drops off near redline. A Lysholm (twin screw) power band is usually pretty linear across the board.
Reply
Old Mar 25, 2011 | 09:37 PM
  #20  
Syritis's Avatar
Can Post Only in New Member Section
iTrader: (2)
 
Joined: Jul 2004
Posts: 930
Likes: 0
From: Calgary, Canada
yes there are small differences between the S/Cs but their boost gains are based on rpm and rpm rises at a liner rate.
turbo's boost gains are based on CFM. for each CFM burned they move ~1.7x more CFM.
Reply
Old Mar 25, 2011 | 10:44 PM
  #21  
RotaryEvolution's Avatar
Sharp Claws
Tenured Member 15 Years
iTrader: (30)
 
Joined: Oct 2003
Posts: 5,107
Likes: 50
From: Central Florida
Originally Posted by -Crash-
Karack is fabbing up a mount for an Eaton M90, thread is in the 2nd gen forum somewhere.
still waiting for time to permit me to start the fabrication process, i have all the parts ordered for the eaton rebuild.

the M90 is commonly found on ford thunderbird supercoupes which is a 3.8L V6 and should be appropriately sized to make slightly over 200WHP with the proper fuel modifications. but i'm going a step further and keeping the 550WHP capable turbo on the car which is where it may start getting a little hazey as to what to expect from just tossing on the supercharger by itself.

the example should be good for people who want to attempt it though, as those superchargers aren't too difficult to find or very expensive.

it requires a standalone EMS and at least a turbo fuel system to start with, which is where the expenses really come in.

here is the build thread for those who are interested in following it, updates will be a little slow for the next month or 2 though while i work on the 6 or so rebuilds i have in the shop.
https://www.rx7club.com/showthread.p...t=twin+charged

Last edited by RotaryEvolution; Mar 25, 2011 at 10:49 PM.
Reply
Old Mar 27, 2011 | 01:15 AM
  #22  
Evil Aviator's Avatar
Rotorhead
Tenured Member 15 Years
 
Joined: Feb 2001
Posts: 9,136
Likes: 39
From: Charlottesville, Virginia, USA
Originally Posted by Syritis
yes there are small differences between the S/Cs but their boost gains are based on rpm and rpm rises at a liner rate.
turbo's boost gains are based on CFM. for each CFM burned they move ~1.7x more CFM.
There is a BIG difference when it comes to the centrifugal supercharger. Its boost level is based on the square of its input shaft speed, which means that its boost rises very slowly (slower than a typical turbocharger), and it will not produce max boost until the engine hits redline. I just wanted to make this clear because many people don't understand this, and are very disappointed when the results do not live up to their expectations.

Turbos work on mass airflow (lbs/min) as opposed to volume airflow (cfm). The old compressor maps that used cfm were dumbed-down for the hotrodders of yesteryear who had a very limited engineering education and were accustomed to the carb cfm ratings.
Reply
Old Mar 27, 2011 | 02:07 AM
  #23  
BurritoBut's Avatar
Full Member
Tenured Member 10 Years
 
Joined: Jan 2009
Posts: 152
Likes: 0
From: Auckland, New Zealand
My friends rx4
http://www.youtube.com/watch?v=0Lh4gLA4JW0
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Th0m4s
Build Threads
25
Feb 26, 2019 02:04 AM




All times are GMT -5. The time now is 06:49 PM.