Go Back   Rotary Car Club > Tech Discussion > RX-7 2nd Gen Specific (1986-92)

RX-7 2nd Gen Specific (1986-92) RX-7 1986-92 Discussion including performance modifications and technical support sections.


Welcome to Rotary Car Club.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Reply
 
Thread Tools Display Modes
Old 05-04-2010, 10:14 PM   #1
88turboii
destroy, rebuild, repeat
 
88turboii's Avatar
 
Join Date: Feb 2008
Location: Charleston, SC
iTrader: (0)
Posts: 395
Rep Power: 17
88turboii is on a distinguished road
Default ball-bearing hybrid turbo results

so i did it, i made a BB hybrid using a garrett BB chra, but did not get the results i expected. I was running a 60-1 hifi compressor with p-trim turbine wheel on stock journal bearings before. all i did is order a garrett BB 60-1 chra with p-trim wheel and swapped compressor backplate with my hifi and bolted the hifi compressor cover on. With some minor clearancing it fit pretty well. and the coolant ports were 14mm instead of 16mm, but no big deal

but.. spool seems to have gotten worse by about 500 rpm, i used to get 15 psi by 3500 rpm with the journal bearing, now it doesnt hit 15psi till after 4k! what gives? the only reason i can think of why it spools slower is the added rotating mass from the inner race on the turbine shaft.. where as journal bearing has no inner race






__________________
1993 RX-7 Touring MB, stockport 13B-REW, 9.4CR rotors, T04S 60-1/p-trim single turbo
1986 RX-7 Base project track beast

Last edited by 88turboii; 05-04-2010 at 10:17 PM..
88turboii is offline   Reply With Quote
Old 05-04-2010, 10:51 PM   #2
RETed
RCC Addict
 
Join Date: Mar 2008
Location: Honolulu, Hawaii USA
iTrader: (1)
Posts: 1,813
Rep Power: 18
RETed will become famous soon enough
Default

Interesting...

Assumed the turbine housing is identical?

Long shot...turbine wheels clearances are different?

Maybe the BB CHRA wasn't broken in?
How many miles did you run it before you ran it on the dyno?


-Ted
__________________
reted_2000@yahoo.com
Technical Advisor
FC3S Pro
http://fc3spro.com/



Quote:
Originally Posted by TitaniumTT View Post
because you're only as good as your backup
RETed is offline   Reply With Quote
Old 05-06-2010, 05:11 PM   #3
88turboii
destroy, rebuild, repeat
 
88turboii's Avatar
 
Join Date: Feb 2008
Location: Charleston, SC
iTrader: (0)
Posts: 395
Rep Power: 17
88turboii is on a distinguished road
Default

yah same turbine housing. ive put about 250 miles on it. turbine clearance could be it.. i will pull it again and check that

edit: turbine clearance is the same with the stock center section..

Last edited by 88turboii; 05-15-2010 at 06:37 PM..
88turboii is offline   Reply With Quote
Old 07-08-2010, 08:21 PM   #4
88turboii
destroy, rebuild, repeat
 
88turboii's Avatar
 
Join Date: Feb 2008
Location: Charleston, SC
iTrader: (0)
Posts: 395
Rep Power: 17
88turboii is on a distinguished road
Default

just an update i found out my turbo-manifold gasket is blown out. Last weekend i swapped the journal bearing setup back on and it was having trouble making 5psi! the bb would make 15psi, just late. so with the new gasket the bb should spool hella fast. gasket will be here next week
88turboii is offline   Reply With Quote
Old 07-08-2010, 08:59 PM   #5
lt1_fd3s
WNC Tour Guide
 
lt1_fd3s's Avatar
 
Join Date: Feb 2008
Location: WNC
iTrader: (3)
Posts: 780
Rep Power: 17
lt1_fd3s is on a distinguished road
Default

Quote:
Originally Posted by 88turboii View Post
just an update i found out my turbo-manifold gasket is blown out. Last weekend i swapped the journal bearing setup back on and it was having trouble making 5psi! the bb would make 15psi, just late. so with the new gasket the bb should spool hella fast. gasket will be here next week
so when u coming back up to the hill with it?
__________________
WNC Tour Guide - Including the Tail of the Dragon - PM for details
lt1_fd3s is offline   Reply With Quote
Old 07-08-2010, 08:41 PM   #6
sen2two
KTEC
 
sen2two's Avatar
 
Join Date: Jan 2009
iTrader: (2)
Posts: 642
Rep Power: 0
sen2two is on a distinguished road
Default

is this dual or single ball bearing?
__________________
what I have:
1985 Gs:12a All motor Drag car - 1973 Rx2: Play car
What I had:
93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2
sen2two is offline   Reply With Quote
Old 07-10-2010, 04:50 PM   #7
junito1
The Newbie
 
Join Date: Mar 2010
iTrader: (0)
Posts: 12
Rep Power: 0
junito1 is on a distinguished road
Default

Interesting. Waiting for results.
junito1 is offline   Reply With Quote
Old 07-16-2010, 09:44 AM   #8
N.RotaryTech
Home-brew Rotary
 
N.RotaryTech's Avatar
 
Join Date: Feb 2008
Location: GooseCreek SC
iTrader: (0)
Posts: 552
Rep Power: 17
N.RotaryTech is on a distinguished road
Default

.
N.RotaryTech is offline   Reply With Quote
Old 07-16-2010, 09:45 AM   #9
88turboii
destroy, rebuild, repeat
 
88turboii's Avatar
 
Join Date: Feb 2008
Location: Charleston, SC
iTrader: (0)
Posts: 395
Rep Power: 17
88turboii is on a distinguished road
Default

well i replaced the gasket, still have the leak.. the engine-to-manifold gasket looked good to me, but i guess ill try replacing that next. it is a dual bearing center

the one problem i did notice is the garrett "top hat" looking thing on the exhaust side has a thicker lip than stock, and i think it may be causing the leak. If i did it again, i would use the stock piece
__________________
1993 RX-7 Touring MB, stockport 13B-REW, 9.4CR rotors, T04S 60-1/p-trim single turbo
1986 RX-7 Base project track beast

Last edited by 88turboii; 07-16-2010 at 09:50 AM..
88turboii is offline   Reply With Quote
Old 08-02-2010, 07:11 AM   #10
88turboii
destroy, rebuild, repeat
 
88turboii's Avatar
 
Join Date: Feb 2008
Location: Charleston, SC
iTrader: (0)
Posts: 395
Rep Power: 17
88turboii is on a distinguished road
Default

to date ive replaced both gaskets, did some minor resurfacing of the manifold and checked for cracks, and i can still hear a slight exhaust leak. sounds like rattling on decel. started hearing it ever since i first installed the bb chra. im thinking their is a leak at the top hat piece between the turbine housing and the center.

weird thing is im not sure why the stock center had problems when i swapped it on, i cant remember if i heard the rattle with it, maybe i didnt have the compressor and turbine wheels lined up right and were out of balance. would wheels out of balance cause such a difference?

Last edited by 88turboii; 08-02-2010 at 07:19 AM..
88turboii is offline   Reply With Quote
Old 03-18-2011, 09:11 AM   #11
captanmike
The Newbie
 
Join Date: Mar 2011
iTrader: (0)
Posts: 1
Rep Power: 0
captanmike is on a distinguished road
Default

Hello

Did you ever get this working?
I would be very interested to know what sort of difference it made.

-Mike Brunt-
captanmike is offline   Reply With Quote
Old 04-10-2011, 12:33 AM   #12
88turboii
destroy, rebuild, repeat
 
88turboii's Avatar
 
Join Date: Feb 2008
Location: Charleston, SC
iTrader: (0)
Posts: 395
Rep Power: 17
88turboii is on a distinguished road
Default

ok i finally got another housing milled out for the thicker bb heat shield piece, and spool problem is fixed. 10 psi by 3000 15psi by 3500. i think it was spacing the turbine wheel too far away from the turbine housing. spool seems to be about the same as the journal bearing, although i still hear the exhaust leak rattle sound. but im happy with it. i will try to get it on the dyno soon and see where shes at
88turboii is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:41 AM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Hosted by www.GotPlacement.com
Ad Management by RedTyger