MR2 Roadster Owners Club

The Workshop => Performance Related => Topic started by: J88TEO on April 7, 2021, 20:06

Title: To wrap or not to wrap
Post by: J88TEO on April 7, 2021, 20:06
Had a Toyosport SS manifold since nearly 2 years ago...never had the time to install it!
Will get it installed when the weather is better.
Question - to wrap or not to wrap?
Title: Re: To wrap or not to wrap
Post by: 1979scotte on April 7, 2021, 20:25
Quote from: J88TEO on April  7, 2021, 20:06Had a Toyosport SS manifold since nearly 2 years ago...never had the time to install it!
Will get it installed when the weather is better.
Question - to wrap or not to wrap?



Not
Title: Re: To wrap or not to wrap
Post by: Carolyn on April 7, 2021, 20:31
Wrap.
Title: Re: To wrap or not to wrap
Post by: Petrus on April 7, 2021, 20:36
Depends ;-)

If you can refit the heat shields then nót.
If you can not, you might.
Title: Re: To wrap or not to wrap
Post by: Joesson on April 7, 2021, 20:55
That's pretty conclusive then!
Title: Re: To wrap or not to wrap
Post by: J88TEO on April 7, 2021, 20:57
Thanks.
Yes...conclusive!
Title: Re: To wrap or not to wrap
Post by: Beachbum957 on April 7, 2021, 21:13
Maybe / maybe not

https://help.summitracing.com/app/answers/detail/a_id/4801/~/should-i-wrap-my-headers%3F (https://help.summitracing.com/app/answers/detail/a_id/4801/~/should-i-wrap-my-headers%3F)

Personally, I would not. We have been running a similar header for over 13 years, not wrapped, and no issues.
Title: Re: To wrap or not to wrap
Post by: Ardent on April 7, 2021, 22:04
Not
Title: Re: To wrap or not to wrap
Post by: Dev on April 7, 2021, 22:54
I initially was warned about the dangers of wrapping since it is a highly debated issue so I did not but over time it appears that the majority of those that wrapped did not have any of the alarmist issues of headers cracking or warping. I'm sure it depends on the quality of the construction and if material gets wet or if the car is raced. I wrapped mine about five years ago with no adverse effects on a 15 year old header. Street use probably prolongs the life where it doesnt matter as much.

What I did notice was a major reduction in under hood temps making it worth it for me.
Title: Re: To wrap or not to wrap
Post by: Smithy on April 8, 2021, 15:36
Quote from: J88TEO on April  7, 2021, 20:06Had a Toyosport SS manifold since nearly 2 years ago...never had the time to install it!
Will get it installed when the weather is better.
Question - to wrap or not to wrap?

If you don't wrap then don't forget to clean it before getting it up to temperature. I didn't clean off the fingerprints and grease off mine before getting it hot. My nice polished manifold looks awful now. 
Title: Re: To wrap or not to wrap
Post by: J88TEO on April 8, 2021, 21:08
Noted with thanks.
Title: Re: To wrap or not to wrap
Post by: Zspeed on July 23, 2021, 22:03
Do these answers apply the same to back box and pipes? I have seen some recently where these have been partially wrapped as well.
Title: Re: To wrap or not to wrap
Post by: Ardent on July 23, 2021, 22:20
Cannot recall seeing or hearing of stock stuff being wrapped.

Very very distant memory of an after market box being wrapped and not ending well. Probably best ignore that as could easily be mixing up two very distant memories.
Title: Re: To wrap or not to wrap
Post by: The Other Stu on July 23, 2021, 22:49
Quote from: Ardent on July 23, 2021, 22:20Cannot recall seeing or hearing of stock stuff being wrapped.

Very very distant memory of an after market box being wrapped and not ending well. Probably best ignore that as could easily be mixing up two very distant memories.

But the stock stuff is wrapped. In metal. Lots of it!

My thoughts on wrapping:

For: heat soak. Hot air going into your engine is not good. Even my rudimentary knowledge of engines say that cold air is much better than warm, and having once had a mushroom intake in and around an engine bay, I lost a LOT of power.

Also, warm air molecules travel faster. Basic physics says that you want the hot air out of your engine ASAP


Against: some say they can cause cracking of the £120 manifold. I've got a Toyosport one which is 5 years old and has absolutely no signs of cracking.
There are people who this has happened to, but I've also heard of cracking ones that weren't wrapped.

TL:DR? Scientific benefits for me outweigh the possible side effects.
Title: Re: To wrap or not to wrap
Post by: Ardent on July 23, 2021, 22:51
ceramic coating?
Title: Re: To wrap or not to wrap
Post by: Zspeed on July 24, 2021, 06:28
Sorry, it is aftermarket boxes and pipes as well as more common manifolds I have seen wrapped.

My engine bay does seem hot compared to other cars I have run so it must help. I'm about to put stock air box back on as I don't think the other thing the previous owner put in is doing it any good.
Title: Re: To wrap or not to wrap
Post by: Beachbum957 on July 24, 2021, 11:32
Quote from: The Other Stu on July 23, 2021, 22:49Against: some say they can cause cracking of the £120 manifold. I've got a Toyosport one which is 5 years old and has absolutely no signs of cracking.
There are people who this has happened to, but I've also heard of cracking ones that weren't wrapped.
There are various reports of the cheap clone headers cracking, wrapped or not wrapped.  But many of these either didn't even have the lower mounts, or were on PFL models with the stamped mounts. Vibration is a killer. We have run a cheap header for over 35,000 miles (not wrapped - just OEM heat shields) with no problems using the later model cast brackets to cut the vibration.

As for wrap vs no wrap, the only comment is most header manufacturers will void any warranty if a header is wrapped.  Not that the cheap clones had any warranty to start with!
Title: Re: To wrap or not to wrap
Post by: 1979scotte on July 24, 2021, 12:15
I'd wrap the manifold if I could be bothered and the cat but not the actual back box.
FYI don't worry about the engine bay heat it's nothing compared to when you add a turbo.
Title: Re: To wrap or not to wrap
Post by: Dev on July 24, 2021, 13:14
Quote from: Ardent on July 23, 2021, 22:51ceramic coating?

I have ceramic coated my header long ago. It helped a little but wrapping helped a lot. 
As far as wrapping all of the exhaust components Its not a good idea. The weight penalty is too much. Wrapping the header has the maximum benefit, anything more is diminishing returns. Once the car is in motion the heat exits out the back anyway. 

Title: Re: To wrap or not to wrap
Post by: ucb on July 24, 2021, 13:21
I purchased mine with a wrapped header