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-   -   just got my knight sports twins rf420 (https://www.rx7club.com/3rd-gen-general-discussion-322/just-got-my-knight-sports-twins-rf420-1106986/)

MILOS7 10-31-16 12:52 AM

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


https://cimg2.ibsrv.net/gimg/www.rx7...6e8a518bfd.jpg

https://cimg0.ibsrv.net/gimg/www.rx7...177780e4d4.jpg

https://cimg3.ibsrv.net/gimg/www.rx7...cfa9183d77.jpg

https://cimg4.ibsrv.net/gimg/www.rx7...c56a25ac52.jpg

https://cimg5.ibsrv.net/gimg/www.rx7...9af16166da.jpg

https://cimg6.ibsrv.net/gimg/www.rx7...90ea95e3b3.jpg

https://cimg7.ibsrv.net/gimg/www.rx7...62a425e7ef.jpg



https://cimg9.ibsrv.net/gimg/www.rx7...38e99f9a6a.jpg

BLUE TII 10-31-16 02:07 AM

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?

MILOS7 10-31-16 02:20 AM

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?

https://cimg7.ibsrv.net/gimg/www.rx7...33171c9e8b.jpg


https://cimg8.ibsrv.net/gimg/www.rx7...53359ad147.jpg

cib24 10-31-16 04:57 AM

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?

MILOS7 10-31-16 05:06 AM


Originally Posted by cib24 (Post 12119975)
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.
https://cimg7.ibsrv.net/gimg/www.rx7...e141f08f44.png


Detail here

MILOS7 10-31-16 05:15 AM

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

https://cimg1.ibsrv.net/gimg/www.rx7...cbaeb531d4.jpg

and close view of the pre control actuator...


https://cimg3.ibsrv.net/gimg/www.rx7...41e421d565.jpg

billyboy 10-31-16 05:17 AM

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.

MILOS7 10-31-16 05:46 AM

[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.



https://cimg2.ibsrv.net/gimg/www.rx7...f29d6a7c5b.jpg

billyboy 10-31-16 06:11 AM

Looks to be stock with a coat of paint, so yeah, a straight swap should do the trick if you have concerns.

MILOS7 10-31-16 06:19 AM


Originally Posted by billyboy (Post 12119981)
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 :scratch:

like this one
https://cimg2.ibsrv.net/gimg/www.rx7...a544a1610a.jpg

BLUE TII 10-31-16 10:46 AM

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.

MILOS7 10-31-16 02:59 PM


Originally Posted by BLUE TII (Post 12120048)
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


https://cimg2.ibsrv.net/gimg/www.rx7...20167e6d7f.jpg



https://cimg3.ibsrv.net/gimg/www.rx7...282b92b9c0.jpg

https://cimg4.ibsrv.net/gimg/www.rx7...6a025e0f36.jpg


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