A Couple Questions About Exhaust Options

[Ron9919]

Today I went up to Altered Atmosphere located in Gaithersburg, MD and went up there looking for a price on exhaust. They showed me a prototype of how the exhaust set-up will look like. It's 3" stainless steel header back Mandrel bent all welded and flanged and muffler for $600. So I then told them that if I got it done it would only be best to get the header and hi-flow cat too. I was going to order the hi-flow 3" in/out cat from gravanatuning.com for $95. But I'm unsure about the header i want something good and cheap but we all know that you can't compair them to each other. So I was going to think about going with the Extrudehone Exhaust Manifold for $250. So what do you guys think about the setup and the prices?

[Watts-Up]

I would say go for it. The choice of headers will grow and the prices will come down a little on some good ones, and you could always add one later down the road. Unless you have the money for the SMS package which includes the high flow cat, downpipe, and rear solid motor mount the help it from jumping around and breaking it. I think it's the nicest header out so far, but still room for improvemnt (IMO)... Also you may want to consider adding in one of Rice eaters bypass Y fitting downpipes so you you could have the option to open that bad boy up too.

[Ron9919]

anybody else?!?!?!?!

[mgm1979]

Personally, I like the CTI setup and the customer service can't be matched! If I had the chance to do it all over again, I'd do it sooner and do a baseline dyno run before hand to see the gains better.

[ArrivalBlueSS]

They are doing putting the downpipe in with there cat back exhaust now?

BTW they prototyped it on my car and I haven't had any issues with it. It's loud if you don't get the silencer thats all.

I would wait for the vibrant header to come out and get that, it's supposed to be out any day now. AAM is a vibrant dealer as well.

[ender]

If you want a trouble free header get the GMEH, it flows about 30cfms more than the stock, with header you have to be careful, most of the really good headers will be around $1000, the sms one is the nisest production header I have seen but I will be going with the cast iron GMEH, less heat transfer and might keep the proper psi in the header, after that you just want the biggest pipe possible to get the exhaust out. Also be carefull with dumps as well, sometimes you LOSE hp with a dump, example the LPE corvettes make 1hp more with a full hi-flow exhaust than with an open header. Its all about gas laws and heat control.

[Sp00ner]

Originally Posted by ender

If you want a trouble free header get the GMEH, it flows about 30cfms more than the stock, with header you have to be careful, most of the really good headers will be around $1000, the sms one is the nisest production header I have seen but I will be going with the cast iron GMEH, less heat transfer and might keep the proper psi in the header, after that you just want the biggest pipe possible to get the exhaust out. Also be carefull with dumps as well, sometimes you LOSE hp with a dump, example the LPE corvettes make 1hp more with a full hi-flow exhaust than with an open header. Its all about gas laws and heat control.

heat transfer and proper psi in the header?

[ender]

cast iron will not give off as much heat, it takes mroe to heat up the header and it will soak up the heat and not transfer the haet into the engine compartment as much as a thin steel header will the psi was a stab at back pressure, but when you say back pressure people talk about fart cans and hondas and I didn't want that.

the simple explaination is that you want to speed up the flow at the header to help the piston push the air out, so if its to small it makes the piston work harder and if its to big it doesnt help pull the exhuast out so you need the baby bear solution but anyone that makes headers is probably not going to try to figure out what size flows the best, too expensive. After the header you just want to move the air out the speed of which becomes less critical because you will keep pushing air into the exhaust system it will drive it towards the back.

Just think about the venture(sp) effect of air, when you pump it through a smaller tube you increase speed, to small and you have a blockage, to big and you don't get the effect.

Thats why I am doing the GMEH option.

[fullthrottle]

Originally Posted by Ron9919

anybody else?!?!?!?!

sounds like a decent deal fo a decent cat back set up. go for it man

[blurryredline]

GMEH is what i would go with until we have something else proven and reliable on the market... its also covered under warranty!