Rear Turbo Setup
#67
Former Vendor
![](/mt2011/images_td/ranks/supporter1.gif)
iTrader: (31)
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,103
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Because we don't give trophies for participation here. If you aren't ready for criticism and a thorough questioning of the logic behind your build choices, I strongly advise you to find another forum to post your build on. If you can handle the criticism and justify your logic, you'll do just fine here.
Last edited by Savington; 12-18-2015 at 06:22 PM.
#68
SADFab Destructive Testing Engineer
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/moderator.png)
iTrader: (5)
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 18,642
Total Cats: 1,866
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
To elaborate on what Sav said its basically that bullshit isn't tolerated here. You can't show up and say a rear mounted turbo is the best thing since sliced bread (which you haven't. But I'm making a point) and not back it up with technical reasoning.
Don't take it as hostile, we like cool and innovative things.
I still think the setup is really cool, and am interested in results. The only other rear turbo setup I know of is on a V8 making 600hp+ I believe.
Don't take it as hostile, we like cool and innovative things.
I still think the setup is really cool, and am interested in results. The only other rear turbo setup I know of is on a V8 making 600hp+ I believe.
#70
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Hi Corky, In the beginning with the packed ceramic bearings the turbo does not spin totally freely like ball bearings right out of the gate. After a couple hundred miles the shaft and bearings seat and the turbo spins really freely. I remember the FRS after I'd turn the motor of I could stand there and listen to the turbo slowly wind down. I was shocked how long it took. That's just my experience. I will raise the boost and see how that helps the low end, unless the waste gate is leaking how would that come into play??
#71
SADFab Destructive Testing Engineer
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/moderator.png)
iTrader: (5)
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 18,642
Total Cats: 1,866
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
You are right about both points.
Grease packed ball bearings get better as they wear in. I just installed some sealed wheel bearings in my truck and they were totally stiff. Now they are smooth.
Only way raising boost will help is if the wastegate is getting blown open because of lack of preload.
Grease packed ball bearings get better as they wear in. I just installed some sealed wheel bearings in my truck and they were totally stiff. Now they are smooth.
Only way raising boost will help is if the wastegate is getting blown open because of lack of preload.
#72
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
You are right about both points.
Grease packed ball bearings get better as they wear in. I just installed some sealed wheel bearings in my truck and they were totally stiff. Now they are smooth.
Only way raising boost will help is if the wastegate is getting blown open because of lack of preload.
Grease packed ball bearings get better as they wear in. I just installed some sealed wheel bearings in my truck and they were totally stiff. Now they are smooth.
Only way raising boost will help is if the wastegate is getting blown open because of lack of preload.
#77
Boost Czar
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/admin.png)
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,688
Total Cats: 4,113
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Don't take it as hostile, we like cool and innovative things.
I still think the setup is really cool, and am interested in results. The only other rear turbo setup I know of is on a V8 making 600hp+ I believe.
SLEEPER Miata Shocks 600hp Z06! [STREETS] - YouTube
Also, this was the last rear mounted guy we had to deal with:
it made 170rwhp at 15psi. It hit 15psi at redline.
and this jewel when he was still using the AFM:
I'm trying to find the one video where he was randomly at a car show and broke his spolier by trying to sit on it.
#78
Boost Czar
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/admin.png)
iTrader: (62)
Join Date: May 2005
Location: Chantilly, VA
Posts: 79,688
Total Cats: 4,113
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
or this gem that came and went:
![](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/157936-rear-turbo-setup-turbo.jpg?dateline=1450803791)
This turbo caught on fire or something last I heard, apparently you shouldn't run turbos without any cooling/ventilation.
![](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/157936-rear-turbo-setup-turbo.jpg?dateline=1450803791)
Volvo 440 turbo as its nice and small to minimize spool up time.
Boost came in about 4k, lag was almost non-existant.
#80
Boost Pope
![](/mt2011/images_td/ranks/supporter1.gif)
![](/mt2011/images_td/ranks/smod.png)
iTrader: (8)
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,339
Total Cats: 6,793
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
We've seen a fair number of crappy turbo setups around here. Some of them have been rear-mounted, some haven't.
But to be fair, this Roadstercycle guy seems to have done a pretty good job of it. Wouldn't be my first choice of hardware, but as a former CA resident of 8 years, I appreciate the appeal of the stealth setup.
But to be fair, this Roadstercycle guy seems to have done a pretty good job of it. Wouldn't be my first choice of hardware, but as a former CA resident of 8 years, I appreciate the appeal of the stealth setup.