93redFD

I just got my dp put on at a local muffler shop,and they charge me a $150, I know thats bullshit.. they charged me 40 a few weeks ago to put the mid pipe on.. Well my car was a the shop all weekend and just picked it up.. those ******** soaked that exhaust wrap with pen oil and when that exuast got hot the oil would burn and would smoke .. I just got it taken off and no smoke. My ?? is, Do I need to put wrap back on??? I called RP and they told me that leaving it off was fine,, I s that true.. the lady at the desk told me..
And also do I need to unplug the air pump?

pomanferrari

iTrader: (1)

IF YOU'RE RUNNING A CAT, THEN IN MY EXPERIENCE NO. NO. NO.

The wrap are very effective, which, along with the cat, causes the heat to remain on the engine side. I've seen similar problems with the 80's style BMW 5 series that had a thermal reactor instead of a cat. These engines eventually crack their heads. My friend has melted 4 Mazda reman- going on the fifth one. I told him after the 2nd one that it's his wrap and Cat. He didn't believe me and didn't care as his warranty keeps paying for reman.

$150 to do the dp at $60/hr. is cheap. Normally runs $250 around here if no broken stud. I did mine in 4 hours. didn't break any stud but had to retap 2 holes.

bee

keep it wraped..

keeps alot of heat out of the engine bay. You dont have to un plug the air pump. I wouldnt un plug it unless you have an aftermarket ecu, which you should have with those mods. Unplugging it with the stock ecu results in a horribly lumpy idle.

toddah

Poman,
What are you talking about ?
What parts on your "friends" Rx7 were damaged by wrapping the DP? I don't understand how keeping the heat inside the pipe would raise any engine parts to the melting point. I think your friend should take his RX to a QUALIFIED mechanic and have the basics checked out
1 Fuel
2 Timing
3 Cooling
I think he should stop chasing goofball **** like DP wrap.
I would think after 4 motors the shop he is going to would simply tell him NO more.
Sorry man no hard feelings but BS is BS.

RX7Elmo

i second or um..3rd keeping the wrap on. It should reduce under hood temps. Keeping the heat inside the pipe and out the tailpipe. I'm meaning to buy some myself and wrapping the downpipe. I think this should be considered a "reliability mod" as well.

Danny

GoneSilent

I'd only tape the pipe up if you have stainless steel. Anything else will rust 5X faster with the tape on it.

93redFD

I have dp, mp, cb, and power fc.. wow 150 is cheap, damn they even broke a stud to.. the reason I thought it was alot is beacuse they charged me 40 to put the mid pipe on. The dp already had wrap on it but the it was saoked in penetrating oil and the oil would burn off and it looked like the the car was overheating plus it was embrasing at red lights..

MastaCow

How do you figure this? The only way I could see this happening is if you don't drive the car often and the wrap gets wet from condensation or if you hit a puddle on the way into the driveway. Otherwise, the exhaust heat will cause any moisture to evaporate.

5x? are you pulling numbers out of your butt?

j9fd3s

iTrader: (3)

i'll send you a wrapped mild steel one, the wrap is the only thing holding it together, it lasted 3 years?

2) $150 is way cheap to put a dp on, anyone whos done one themselves knows that, and if the wrap is off i would leave it off it is not that big of a deal. my dp is wrapped, but i dont think it made an important difference

mike

MastaCow

I'd like to see this. you paying shipping?

So you're saying that the exhaust wrap causes the MS to rust on its own?

paw140

Are you saying that a wrapped dp will increase your temp sensor readings by 600+? I don't have any experience with this, but that just doesn't seem reasonable.

About the rusting out problem: I've heard a lot of other people say that wrapping exhausts will make them rust faster. I'm assuming hotter temps speed up the oxidation process, and I'm pretty sure this is a valid problem.

I wrapped my HKS dp when I put it in 4 months ago... but I can't really draw any conclusions yet. I'll let you know in another few years

Poman: I'm also curious to hear more details about the melting engine thing. I don't see how thats possible, and what exactly is melting?

pomanferrari

iTrader: (1)

Hey, Thanks Gordon for the anecdotal... I'm not a practicing mechanical engineer any more but I know enough about thermodynamics to figure out that this wrap will warp your housings.

Let me reiterate: IF YOU'RE RUNNING A CAT, DO NOT WRAP YOUR DP. I'm not sure about WRAP with MP but I'm very sure about the former configuration. My guess is not to do it since there is a turbo that stores quite a bit of heat too.

jspecracer7

Don't wrap. I've seen 4 years old frontpipe's/midpipe's without wrap and they've survived through saltwater air and about 8 typhoons a year...no rust...so what's the point?

Plus what Gordon said...EGT is VERY important.

jspecracer7

Gordon,

Are these numbers in Celsius? 1400 seems quite high, even for high boost FD's. The reason I ask is because when I tuned my car, I found that at 4th Gear, at about 7000 rpm's WOT and boosting 1.0 kilos, my EGT was around 910 C with tuning more towards the rich side.

jspecracer7

Thanks for the info Gordon. I intentionally tune rich, but haven't had enough data logit runs to start lowering the fuel.

Yeah, 1670 Fahrenheit and a lean A/F condition would definitely spell BOOM

grampa

Interesting, I saw no real change in the EGTs after wrapping. The only comment I got from Dave Barninger is that it made putting in and taking out his wb o2 sensor much more comfortable (much cooler).

I also ran wrap on my last car with mild steel for four years and it did not rust much at all. I also did not drive it in the rain that much.