I can't get a clear anwser on this. It was measured at the downpipe. My car is stock except for a downpipe please help!

 

not too much if u just putt around as some do, and rarely use max power.

if u want more usable power, start the upgrades. search for mods, upgrades, etc.

 

Yeah, I agree. I would say that if you are just tooling around you should be okay.

 

I was told by a shop that this is way to high for an fd, is this true? Do i need to replace my cat? Thats what they were saying.

 

What's the problem that you are experiencing which the shop thinks you need to replace your cat for (or that they were checking the back pressure)?

If you take a look at this thread:

https://www.rx7club.com/forum/showth...=back+pressure

7 lbs of back pressure with a high flo cat, so 8 lbs with the stock cat doesn't sound like it's clogged...

 

Let me explain in greater detail. I have alot of hissing coming from my engine bay and my downpipe glows on the part that connects to the engine. So I was thinking that the back pressure from my "clogged" cat could be the reason for the glowing downpipe and possible the vaccume hoses hissing possible because they have blow off. Rotary Gods does this make since? As is it turns out the shop that told me about my clogged cat is not reputable, thanks.

 

The upper part of the downpipe can/will glow redish orange due to the heat sometimes (after some spirited driving or something). That's pretty typical.

However, the hissing sound... When you do hear it?

 

When ever i touch the accel petal. The harder i press the slower the acceleration. Weird huh? By the way thanks for the responce, you saved me 450 bucks on a new cat!!

 

Do you have a boost gauge installed?

If not, this is the *ideal* time to get one. If you do, what boost pattern are you seeing?

 

12-10 is what my mechanic said. i think i am going to take the intae pleneum off and look for loose vaccume hoses and buy a boost gauge today.

 

If you are going to go under the hood yourself, you may as well purchase a boost gauge and hook it up.

Just pick up a cheap one. You won't be staring at it every day, but they REALLY help in situations like these.

http://66.216.67.51/product.asp?0=212&1=270&3=388

12-10 what? Is that suppose to be your boost pattern? Did your mechanic happen to mention what your vacuum was?

 

No he didn't mention my vaccume. It was a Mazduh mechanic (idiot). To make a long story short I buy a new engine from mazda and have them install it and it runs 100 times worse then the original engine! Sorry had to vent. The boost pattern the mechanic said was 12 and slowley pull back to 10. But who knows.

 

lol, ok... There are some good Mazda mechanics that do know how to work on the cars, however, finding them is harder than finding that needle in the haystack.

Your best bet at this point is to get a boost gauge, hook it up and check the following things:

1. Vacuum at ildle (idle should be around 750-800 rpms)

2. Do the boost test: http://www.scuderiaciriani.com/rx7/boost_test.html

Once you have those results, it will be much easier to troubleshoot what is going on. Good luck!

 

Thanks!!