Is the exhaust manifold heat shield necessary?

Anonymous · September 15, 2004, 02:36

I have decided to install the TRD headers, to improve performance and to set my mind at ease regarding pre-cat failure. Question: When this is done, must I reinstall the heat shield? s:(

s:( I would rather be able to lift the engine cover and admire the headers from time to time. Just what is it protecting, anyway?

Anonymous · September 15, 2004, 05:00

It keeps the heat in the header... a good thing for gas flow and underhood temps. Provides some protection against rusting header, I would imagine.

Have you heard about gutting your precats? It may not give as much oomph as a TRD header, but I think it would be close.

Anonymous · September 16, 2004, 14:17

The heat shield will fit perfectly on the TRD exhaust manifold and it will look a hell of a lot better than the ugly grey insulating tape you would otherwise wind on your "bare" manifold... This is the case for non-TRD models.

Personally I thought the TRD exhaust manifold is a little bit on the expensive side and I am not sure whether you would notice much difference (in power and sound) compared to a "gutted out" stock manifold... s:?: :?: s:?:

Anonymous · September 16, 2004, 17:24

Thanks for the help, everyone. s:D

s:D Actually, I am going TRD primarily to avoid pre-cat failure without doing the gutting routine. That, in my mechanic's opinion, would surely compromise the remaining portion of my drive-train warranty, in addition to the extended warranty I purchased. He also thinks the headers will provide a noticeable increase in power (in tandem with the low-restriction air cleaner and Remus exhaust system I already in-place). The Remus sound is fine as it is, so I don't really care about more decibels.

heathstimpson · September 17, 2004, 06:47

What is the price of the TRD header please s:?: :?: s:?:

GSB · September 17, 2004, 06:50

Quote from: "heathstimpson"What is the price of the TRD header please s:?: :?: s:?:

Loads... reckon on about £600-£650...

heathstimpson · September 17, 2004, 06:52

Quote from: "GSB"
Quote from: "heathstimpson"What is the price of the TRD header please s:?: :?: s:?:

Loads... reckon on about £600-£650...

s:shock: :shock: s:shock: s:shock: :shock: s:shock: I think I'll gut my precats then

Anonymous · September 17, 2004, 10:35

Quote from: "heathstimpson"
Quote from: "GSB"
Quote from: "heathstimpson"What is the price of the TRD header please s:?: :?: s:?:

Loads... reckon on about £600-£650...
s:shock: :shock: s:shock: s:shock: :shock: s:shock: I think I'll gut my precats then

That's what I did (as my pre-cats were going seriously bad)...

Had the TRD manifold been say €500 or so, I would have gone for it. But €1099 is just toooo much for maybe 3 or 4 extra bhp.

http://www.mrs-passion.com/catalog/index.php?cPath=3_18

But if it can solve the warranty issue, it is definitely better than risking a bad pre-cat failure....

Anonymous · September 17, 2004, 10:43

An interesting alternative to the TRD manifold is the PPE hi-flow cat kit:

(This will give you a much more significant boost)

The site is in French but the figures speak for themselves... Other than that, the kit is easy to fit.

http://www.mrs-passion.com/FichesProduits/ppe.html

heathstimpson · September 17, 2004, 14:29

How much cheaper is the PPE jobbie then s:?: :?: s:?:

Bongo · September 17, 2004, 14:39

looks like it's €730 so about €369 cheaper. s:? :? s:?

Anonymous · September 17, 2004, 15:41

It's cheaper and it replaces the stock catalytic converters (including the main cat) with a free-flowing one s:twisted: :twisted: s:twisted: ... According to some guys who fitted it, it will pass emissions tests OK.

However, the heat shield won't fit and therefore you should wrap it with special manifold insulating tape. (Doesn't look nice, but performs nicely!)

Anonymous · September 17, 2004, 15:44

You can also contact "dieamond" (the owner of that e-commerce site) to ask him about prices (they can be negociated depending on how much stuff he ships over in one go s:wink: :wink: s:wink: )

Anonymous · September 17, 2004, 19:56

Just bear in mind that without the restriction imposed by the precats in the stock header, which results in more heat build up, the TRD header will not dictate as great a need for the heatshield so I don't see a problem with leaving it off.

I think the PPE header is aggod alternative but rememebr that there has been some discussion over the O2 sensor placemnt and how that affects the running of the engine being further down the header. Also you will need to do some jiggery pokery with an O2 conditioner for the second O2 sensor as I beleive it uses only one O2 sensor.

Slacey · September 18, 2004, 08:54

Quote from: "RUSTY"Also you will need to do some jiggery pokery with an O2 conditioner for the second O2 sensor as I beleive it uses only one O2 sensor.

It does use only one, but they provide you with a harness that gives readings to both O2 sockets from one sensor.

Tem · September 19, 2004, 15:35

Quote from: "phat"However, the heat shield won't fit and therefore you should wrap it with special manifold insulating tape. (Doesn't look nice, but performs nicely!)

Those tapes are one of the best ways to capture moisture and make stuff go bad. PPE headers and pipes come coated anyway, which keeps it nice and cool. My engine temp actually decreased with the PPE header...

LeeUK · September 29, 2004, 15:08

I'm getting the PPE manifold and header for Diamond shortly. Going on from the manifold heat shield is it worth removing the rest of the shielding around the exhaust? I have an a'pexi CAI with the heat sheild to prevent drawing in heat directly from the exhaust but the sheild fits in very tight and would be better if i removed the other heat shields. Plus it would look much nicer! s:D

s:D

Just wondering if it would have any devestating effects on performance?

Anonymous · September 29, 2004, 21:59

Just in case of general interest s:wink: :wink: s:wink: :

TRD Header (US import, 799 US$ + 25 US$ postal service):

and with installed heat-shield:

Anonymous · October 4, 2004, 20:44

QuoteI am going TRD primarily to avoid pre-cat failure without doing the gutting routine. That, in my mechanic's opinion, would surely compromise the remaining portion of my drive-train warranty, in addition to the extended warranty I purchased.

Since I need to buy a set of lower manifold studs and nuts to replace the originals on my stock header, I went over to my dealer (in the U.S.) to pick them up at the shop. The manager was curious to see me buying these and asked what I needed them for. I didn't want to tell them that I was gutting the precats, so I said, "I'm taking off the stock header to try fitting a TRD model."

His reply: "If you replace the header, you'll void the Toyota warranty on your exhaust system." I said, "Well, since I've already installed a dual exhaust, didn't I invalidate the warranty on the exhaust system already?" After a group conference in the shop, the manager returned and said that this was indeed the case."

I decided to confirm this and said, "So... If I modify the exhaust, I take responsibility for that section of the motor, is that it?" The answer was affirmative. This indicates (to me) that gutting the precats, or anything downstream of the manifold, doesn't affect your drivetrain warranty. Personally, it looks as if each dealership pretty much decides how they want to handle these things.[/code]