Is the turbo heat-shield really necessary? - RX7Club.com - Mazda RX7 Forum

Go Back  RX7Club.com - Mazda RX7 Forum > Generation Specific > 2nd Generation Specific (1986-1992)
Reload this Page >

Is the turbo heat-shield really necessary?

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

Is the turbo heat-shield really necessary?

Old 05-26-10, 07:09 PM
  #1  
kel
24 yrs driving 2nd Gen RX
Thread Starter
 
kel's Avatar
 
Join Date: May 2002
Location: A Mile Closer to God (Denver)
Posts: 525
Thanks: 0
Thanked 0 Times in 0 Posts
Is the turbo heat-shield really necessary?

Just replaced the turbo inlet flange gasket and in re-assembly, noticed that the bolt which holds the bottom of the heat-shield is broken off. looks like the previous mechanic tried to remove it and twisted it off flush with the manifold.
Anyway, it appears that the bottom edge of the shield will interfere with movement of the switching actuator unless it's secured to the manifold.

So, if I'm going to reinstall this item, I'll need to drill and tap the manifold from underneath the car.

Question is, am I asking for heat trouble without this thing in place?

- k -
kel is offline  
Old 05-26-10, 07:13 PM
  #2  
Rotary Freak
iTrader: (3)
 
AUGieDogie's Avatar
 
Join Date: May 2003
Location: seattle
Posts: 1,566
Thanks: 0
Thanked 0 Times in 0 Posts
Not really.

It'll cause a bit more heat in the pass. compartment (slight at most) and cook you hoses and wires, again only slightly.
I've been running my 87 for about 5 years with out it and havent' noticed anything bad at all.
AUGieDogie is offline  
Old 05-26-10, 07:25 PM
  #3  
Rotary Enthusiast
 
Join Date: Sep 2009
Location: Simpsonville,SC
Posts: 880
Thanks: 0
Thanked 0 Times in 0 Posts
i havent been running miine without it for as long as ^^ but i have been for about 6 months. and so far havnt had any problem (knock on wood)
florotory is offline  
Old 05-26-10, 07:25 PM
  #4  
Driving RX7's since 1979
iTrader: (43)
 
HOZZMANRX7's Avatar
 
Join Date: Aug 2001
Location: So Cal where the OC/LA/SB counties meet
Posts: 6,096
Thanks: 0
Thanked 1 Time in 1 Post
^I'll be the contrarian and say you should keep it. Do you really want to have cooked hoses and wires? Vacume leaks are a bad thing (petrified tubing), and petrified brittle wire insulation is a really bad thing especially considering the wiring your cooking is what talks to your ECU. There's a reason the Mazda put that shielding there.

I'm at the extream in that I'm running shielding despite I've ceramic coated everything. Over engineering is a good thing.
HOZZMANRX7 is offline  
Old 05-26-10, 07:58 PM
  #5  
kel
24 yrs driving 2nd Gen RX
Thread Starter
 
kel's Avatar
 
Join Date: May 2002
Location: A Mile Closer to God (Denver)
Posts: 525
Thanks: 0
Thanked 0 Times in 0 Posts
Originally Posted by HOZZMANRX7 View Post
^I'll be the contrarian and say you should keep it. Do you really want to have cooked hoses and wires? Vacume leaks are a bad thing (petrified tubing), and petrified brittle wire insulation is a really bad thing especially considering the wiring your cooking is what talks to your ECU. There's a reason the Mazda put that shielding there.

I'm at the extream in that I'm running shielding despite I've ceramic coated everything. Over engineering is a good thing.
I've been leaning this way and you make a great point. My previous TII had petrified vacuum lines and it was a nightmare to troubleshoot.

Anyway, there is no way to drill that out while in the car, but I was able to bend the shield until it sits in place without bothering the switching actuator. Not ideal, but it should work.

thanks to all for opinion and experience.

- k -
kel is offline  
Old 05-27-10, 12:16 AM
  #6  
Rotary Freak
iTrader: (3)
 
AUGieDogie's Avatar
 
Join Date: May 2003
Location: seattle
Posts: 1,566
Thanks: 0
Thanked 0 Times in 0 Posts
I did re-wrap my wire harnes though.....

I really do want to re install mine, just too damn other things to do first.
AUGieDogie is offline  
Old 05-27-10, 01:27 AM
  #7  
WTF is a Piston?..Anyone?
10 Year Member
 
rx-7 obsessed's Avatar
 
Join Date: Apr 2005
Location: regina
Posts: 872
Thanks: 0
Thanked 1 Time in 1 Post
they do help and its very simple why. the turbo is located sooo close to the lower intake manifold that even tho the shield may not do much it will lower intake tempatures by a fair bit. this being said you will not see any preformance from this but, it will help out the car. also it does keep your motor temp a few degrees cooler
rx-7 obsessed is offline  
Old 05-27-10, 11:44 PM
  #8  
Stock boost FTW!
iTrader: (21)
 
Project88Turbo's Avatar
 
Join Date: Nov 2004
Location: Salisbury, MD
Posts: 954
Thanked 27 Times in 20 Posts
If you have ever opened your hood after a hard run at night, you will see why the heat shield is there. The turbine housing will usually be glowing orange from the heat and as rx-7_obsessed stated it is extremely close to the LIM.

Do you really want that much radiant heat being exposed to the LIM? The gasket and water passage o-rings do not like heat and will become brittle. Increased IATs lead to knock, and knock leads to a rebuild.

My heatshield was not salvageable during the rebuild so I wrapped the manifold, put a blanket on the turbine housing, and wrapped the downpipe. PROBLEM SOLVED. Under the hood is now noticeably cooler Did it increase the performance? I can't really tell a difference, but I'm sure I've increased the durability/reliability.

Vince
Project88Turbo is offline  
Old 05-28-10, 10:12 AM
  #9  
Engine, Not Motor
iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,671
Thanks: 0
Thanked 21 Times in 20 Posts
Yes, the heat shield is necessary. In the case of the bottom shield, the engine mount will be baked without it and fail every few years. Now the annoyance of course is fixing up the shield, because in order to do this, you need to remove the turbo and manifold assembly.
Aaron Cake is offline  
Old 05-28-10, 12:45 PM
  #10  
FD Daily
iTrader: (25)
 
K-Tune's Avatar
 
Join Date: Jul 2003
Location: Gulf Breeze, FL
Posts: 3,282
Thanks: 0
Thanked 3 Times in 3 Posts
the manifold shield also protects the lower turbo coolant hose from radiant heat. the turbo shield is absolutely necessary. giving all that radiant heat free reign in the engine bay is just asking for higher temps all around.
K-Tune is offline  
Old 05-28-10, 04:09 PM
  #11  
Apex Seal Treachery!!!!!!
iTrader: (13)
 
JustJeff's Avatar
 
Join Date: Nov 2006
Location: Indiana
Posts: 2,380
Thanks: 0
Thanked 1 Time in 1 Post
The heat shield on mine broke at the weld holding the bolt tabs to the shield. I definitely noticed a difference with that gone, everything on that side of the engine was hotter. I'll be replacing it while doing my rebuild. Like everyone has said, I don't like the idea of adding more heat to 20 yr old parts.
JustJeff is offline  
Old 05-28-10, 04:18 PM
  #12  
Non-op
5 Year Member
iTrader: (2)
 
xeccentric's Avatar
 
Join Date: Jul 2005
Location: San francisco
Posts: 462
Thanks: 0
Thanked 0 Times in 0 Posts
So what about engines with upgraded turbos and mani?
xeccentric is offline  
Old 05-28-10, 04:29 PM
  #13  
spending too much money..
10 Year Member
iTrader: (2)
 
hondahater's Avatar
 
Join Date: Dec 2002
Location: louisiana
Posts: 10,117
Thanks: 0
Thanked 0 Times in 0 Posts
Any sort of heat management is a huge part of keeping a rotary reliable! I've got a heat blanket, and a lower intake manifold heat blanket. I've got heat shilding on all my wires that run close to my turbo area and I'm sure my motor and wires are happy campers for that.
hondahater is offline  
Old 05-28-10, 04:31 PM
  #14  
Engine, Not Motor
iTrader: (1)
 
Aaron Cake's Avatar
 
Join Date: Feb 2001
Location: London, Ontario, Canada
Posts: 29,671
Thanks: 0
Thanked 21 Times in 20 Posts
Originally Posted by xeccentric View Post
So what about engines with upgraded turbos and mani?
Heat wrap everything.

I have two layers of heat wrap on my downpipe, two layers on my manifold, and a nice PTP turbo blanket on the turbine. At some point I'll be making a lower intake manifold shield and a frame rail shield (to deal with the brake and heater lines in that area).

It's easy to tell cars that are run without heat shields because all the underhood rubber turns rock hard. Just imagine what it does to the wiring harness which runs past the turbo.
Aaron Cake is offline  
Old 05-28-10, 04:34 PM
  #15  
spending too much money..
10 Year Member
iTrader: (2)
 
hondahater's Avatar
 
Join Date: Dec 2002
Location: louisiana
Posts: 10,117
Thanks: 0
Thanked 0 Times in 0 Posts
Yeah completely forgot about that, heat wrap is your friend! As well as ceramic coating. I've got my lower and upper intake manifold ceramic coated as well as my hotside to the turbo and manifold. I'm changing to a fully divided manifold now and a different turbo so I'll either get these parts ceramic coated or just use a crap ton of heat wrap and of course the turbo blanket.

edit: at the risk of sounding like a noob... Woot 10,000 posts
hondahater is offline  
Old 05-28-10, 04:35 PM
  #16  
WTF is a Piston?..Anyone?
10 Year Member
 
rx-7 obsessed's Avatar
 
Join Date: Apr 2005
Location: regina
Posts: 872
Thanks: 0
Thanked 1 Time in 1 Post
Originally Posted by xeccentric View Post
So what about engines with upgraded turbos and mani?
as stated above you should heat wrap your turbo housing at the minimum also if you have a down pipe wraping that would be a good idea.....to sum it up my car did not have a heat sheild it was missing...when it rained the water would literaly boil and run off the hood after a sprinted drive....this no longer happens
rx-7 obsessed is offline  
Old 05-29-10, 01:10 AM
  #17  
Rotary Gearhead
5 Year Member
iTrader: (6)
 
scrip7's Avatar
 
Join Date: Jul 2006
Location: Oklahoma City
Posts: 1,187
Thanks: 0
Thanked 0 Times in 0 Posts
The heat shields are not only there to reduce harmful underhood temps, also keep in mind that the energy that acts upon the turbine wheel is not solely from exhaust velocity, but also from heat energy (molecular acceleration) therefore the shields should help contain some of the heat at the turbine housing. Ever notice that extra lag on a cold engine vs a fully warmed one?
scrip7 is offline  
Old 05-29-10, 01:22 PM
  #18  
R.I.P Mark( Icemark )
iTrader: (23)
 
fc3s91's Avatar
 
Join Date: Nov 2001
Location: socal
Posts: 3,912
Thanks: 0
Thanked 0 Times in 0 Posts
Make it look like you are cooking a chicken!!
fc3s91 is offline  
Old 05-29-10, 02:01 PM
  #19  
Apex Seal Treachery!!!!!!
iTrader: (13)
 
JustJeff's Avatar
 
Join Date: Nov 2006
Location: Indiana
Posts: 2,380
Thanks: 0
Thanked 1 Time in 1 Post
Before running into this thread I had planned to simply bend some metal to fit and possibly insulate it similar to the OEM shield.

I'll do some research when time permits, but is exhaust wrap a good choice for a stock S5 turbo and RB downpipe? Seems like it would be easier to use but doesn't it trap water? Seems like the actual turbo would need to breath as it cools down. Wouldn't water condense between the wrap/blanket and turbo and then be trapped there? If there is condensation seems that a metal shield built around it would be better because it would allow the theoretical water to evaporate. Am I on track here or simply talking out of my ***?
JustJeff is offline  
Old 06-23-15, 05:59 AM
  #20  
Full Member
 
Mad_Al's Avatar
 
Join Date: Feb 2015
Location: Italy
Posts: 51
Thanks: 0
Thanked 0 Times in 0 Posts
I ordered a Turbo Blanket and Heat Wrap. Also going to try some heat reflective foil for the underside of the stock TMIC.
Going to post my results once everything arrives
Mad_Al is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
C. Ludwig
Single Turbo RX-7's
49
01-30-19 07:31 AM
FD7KiD
3rd Generation Specific (1993-2002)
12
11-12-18 02:49 PM
Th0m4s
Build Threads
24
12-09-17 07:50 PM
ChrisRX8PR
Single Turbo RX-7's
18
08-21-15 02:56 PM
FD7KiD
Single Turbo RX-7's
1
08-18-15 12:50 AM


Thread Tools
Search this Thread
Quick Reply: Is the turbo heat-shield really necessary?


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: