3rd Gen General Discussion The place for non-technical discussion about 3rd Gen RX-7s or if there's no better place for your topic

just got my knight sports twins rf420

Thread Tools
 
Search this Thread
 
Old 10-31-16, 12:52 AM
  #1  
Rotary Enthusiast

Thread Starter
iTrader: (3)
 
MILOS7's Avatar
 
Join Date: Oct 2008
Location: los angeles
Posts: 761
Received 22 Likes on 10 Posts
just got my knight sports twins rf420

bought a set of used twins knight sports RF420,

Your thoughts?

shaft play within specs +-1mm


should I be concern with the slightly bend actuator?

pictures attached



















Last edited by MILOS7; 10-31-16 at 12:54 AM.
Old 10-31-16, 02:07 AM
  #2  
Rotary Motoring

iTrader: (9)
 
BLUE TII's Avatar
 
Join Date: Mar 2001
Location: CA
Posts: 8,226
Received 772 Likes on 511 Posts
Are you sure they are used and not just hybrids build off used stock core turbos?

The exhaust wheels don't look like they have seen exhaust yet.

Or have they been re-rebuilt already?
Old 10-31-16, 02:20 AM
  #3  
Rotary Enthusiast

Thread Starter
iTrader: (3)
 
MILOS7's Avatar
 
Join Date: Oct 2008
Location: los angeles
Posts: 761
Received 22 Likes on 10 Posts
They are used , not rebuilt to my knowledge . Removed from a fd due to single turbo conversion by the previous owner .

you can see the "knight sports" logo on the compressor housing...

Bought it from a guy who works at turbonetics,

they made a "centerpiece" of it as he said , He didn't know if they were rebuild or not .

I guess they cleaned the "turbos"... no clue.

Should I be worried about the bended actuator ?
it seems the compressor housing is missing the "dual nipples ", can I just reuse the one from my old twins?





Last edited by MILOS7; 10-31-16 at 02:40 AM.
Old 10-31-16, 04:57 AM
  #4  
Senior Member

 
cib24's Avatar
 
Join Date: May 2015
Location: UK
Posts: 335
Received 13 Likes on 12 Posts
Assuming you get them installed are you going to run them sequentially or non-sequential?

At say 1.0 bar (14.5 PSI), assuming the same car and modifications, what is the horsepower gain of the RF420s compared to stock twins running 1.0 bar (14.5 PSI)?

Is there a power gain across the entire RPM range? Are the RF420s laggier and by how much? Do the RF420s continue to make power beyond 6,000 RPM unlike the stock twins?
Old 10-31-16, 05:06 AM
  #5  
Rotary Enthusiast

Thread Starter
iTrader: (3)
 
MILOS7's Avatar
 
Join Date: Oct 2008
Location: los angeles
Posts: 761
Received 22 Likes on 10 Posts
Originally Posted by cib24
Assuming you get them installed are you going to run them sequentially or non-sequential?

At say 1.0 bar (14.5 PSI), assuming the same car and modifications, what is the horsepower gain of the RF420s compared to stock twins running 1.0 bar (14.5 PSI)?

Is there a power gain across the entire RPM range? Are the RF420s laggier and by how much? Do the RF420s continue to make power beyond 6,000 RPM unlike the stock twins?
probably gonna keep them seq.

they are rated at 420 PS / 414 hp AT 1 BAR.



Detail here
Old 10-31-16, 05:15 AM
  #6  
Rotary Enthusiast

Thread Starter
iTrader: (3)
 
MILOS7's Avatar
 
Join Date: Oct 2008
Location: los angeles
Posts: 761
Received 22 Likes on 10 Posts
the pre control actuator arm doesn't have the correct position to me...?

view or the pre control actuator arm , angled almost at 90 degres...?

arm on the bottom



and close view of the pre control actuator...


Old 10-31-16, 05:17 AM
  #7  
Rotary Freak

 
billyboy's Avatar
 
Join Date: Jun 2005
Location: sydney
Posts: 1,541
Received 263 Likes on 201 Posts
The stock oem nipple piece coming from the primary compressor housing is a press fit - not threaded. Looks like Knightsport made their own piece there.

The "bend", are you referring to the top of the wastegate actuator, being pushed down slightly, hard to tell from the pic?? It might preload the spring a bit more...and keep the wastegate closed a tiny bit longer...I wouldn't worry, as long as the actuator is serviceable.

All the arm angles look good.
Old 10-31-16, 05:46 AM
  #8  
Rotary Enthusiast

Thread Starter
iTrader: (3)
 
MILOS7's Avatar
 
Join Date: Oct 2008
Location: los angeles
Posts: 761
Received 22 Likes on 10 Posts
[QUOTE=billyboy;12119979]The stock oem nipple piece coming from the primary compressor housing is a press fit - not threaded. Looks like Knightsport made their own piece there.

I thought so , wonder were I could find the right part now...


The "bend", are you referring to the top of the wastegate actuator, being pushed down slightly, hard to tell from the pic?? It might preload the spring a bit more...and keep the wastegate closed a tiny bit longer...I wouldn't worry, as long as the actuator is serviceable.


Here is a better picture,
Since it is bended , I was wondering If I could just swap it with the one from my old twins.



Old 10-31-16, 06:11 AM
  #9  
Rotary Freak

 
billyboy's Avatar
 
Join Date: Jun 2005
Location: sydney
Posts: 1,541
Received 263 Likes on 201 Posts
Looks to be stock with a coat of paint, so yeah, a straight swap should do the trick if you have concerns.
Old 10-31-16, 06:19 AM
  #10  
Rotary Enthusiast

Thread Starter
iTrader: (3)
 
MILOS7's Avatar
 
Join Date: Oct 2008
Location: los angeles
Posts: 761
Received 22 Likes on 10 Posts
Originally Posted by billyboy
Looks to be stock with a coat of paint, so yeah, a straight swap should do the trick if you have concerns.

Thanks for the advises, my main concern now is where to find a dual nipple brass connector

like this one
Old 10-31-16, 10:46 AM
  #11  
Rotary Motoring

iTrader: (9)
 
BLUE TII's Avatar
 
Join Date: Mar 2001
Location: CA
Posts: 8,226
Received 772 Likes on 511 Posts
Can't tell from the pic if the threading they did where the dual nipple used to press in is tapered pipe thread or straight cut threads.

Because there is a reference cut at the top of the threads I would tend to think straight cut threads.

If that is the case you could use a dual banjo bolt to get two nipples.

If its tapered pipe thread you will probably have to do a nipple to a Y fitting or have something custom made.
Old 10-31-16, 02:59 PM
  #12  
Rotary Enthusiast

Thread Starter
iTrader: (3)
 
MILOS7's Avatar
 
Join Date: Oct 2008
Location: los angeles
Posts: 761
Received 22 Likes on 10 Posts
Originally Posted by BLUE TII
Can't tell from the pic if the threading they did where the dual nipple used to press in is tapered pipe thread or straight cut threads.

Because there is a reference cut at the top of the threads I would tend to think straight cut threads.

If that is the case you could use a dual banjo bolt to get two nipples.

If its tapered pipe thread you will probably have to do a nipple to a Y fitting or have something custom made.
here are better pictures, thanks












All times are GMT -5. The time now is 09:49 PM.