Hey, just wondering if anyone has dynoed or seen the dyno results from the GMPP extrude honed exhaust manifold?Also does any one have any good comparisson pics of the stock manifold next to the GMPP extrude one?

 

They look exactly the same from the outside because they are exactly the same except that the internals are smooth. You will not get much of a performance gain from this.

 

I've read that gains are noticable, mabe 6 hp??? I havent seen a before and after though.

 

u can feel the difference as soon as you install it, i was surprised.

 

i have it too, and it is stamped with the same part no, as stock one. only way to tell them apart is looking inside.

 

So then is it really worth the price? I mean, extrude honing the exhaust manif. has been around in racing for 20 years. But in order to get any gains from it, there can't be any bottle necks in the system. So it kinda defeats the whole point of it unless you change your exhaust AND downpipe?

 

ive of 10 whp from the header..

 

i changes exhaust, but now downpipe. the one section of pipe will just create more velocity. no point in changing that unless you stage2+ IMHO

 

But by not changing the down pipe, it just bottlenecks the exhaust flow so it would be no difference with either manifold, the outgoing flow would be the same.

 

the downpipe is quite big stock.

 

IMHO it's worth it... especially if you don't wanna worry about possible warranty issues or hassles with real headers. I got it just b/c it was simple... relatively cheap... and the dealer could install it when they did my exhaust.

 

^^^ what he said. Althought I havent installed mine yet, but I had a stock one besides my GMPP manifold and it has bigger holes and its all smooth inside.

If you dont car for warranty and hassel, by all means go with the DC 4-1 header, but if you care about warranty and stuff like that, get the GMPP one. Either way, you win!

 

in my honest opinion its NOT worth it **** if you have to argue with your dealer that your header didnt cause a problem you either need to work on word choice or get a new dealer , go buy a pacesetter if your looking for cheap

 

^^^ exacly what I was saying!! He wants to put upa fight and tell the dealer to F'off and drive somewhere else. For me driving somewhere else IS a HUGE hassel. They "PROB" wont say anything BUT they might. And if they do it sucks. And I heard numerous times that it makes a difference on the power side!!

 

or you can just take your stock one and have it extra honed and save your money

 

But didnt someone allready tried that and it cost him more than just getting the GMPP one?? I saw that somewhere. And dont forget you need to be exact on this, otherwise one piston will have more flow that the others and that just creates a slight issue. Not as effective

I mean its not a whole lot of $$, F'it and buy one. I got mine for 240 canadian. I mean thats like 200 us!

 

member Nucleur had it done and he said its fine

 

no no, I understand that it will work perfectly fine, but it might not be as "effeciant" as it could/should you know. Thats all.... Do whatever u want bro, I bought one, and only heard preatty good things about them. Personnaly I dont have mine on yet, so I cant tell your for a fact, but there are a few post before giving it props so you can usually trust people that actually have it on their cars and their opinions, not people that heard of stuff and work on the basis of common sense.

 

Can you install this yourself ? Is it hard to do, or does the dealer have to do this?

Is there a how to on this anywhere on this site?

 

240 Canadian? Where did you get it so cheap?

 

Local dealer, he even ordered it in for me actually. He said it was dirt cheap and didnt make sense, but still did it?

 

Problem is if you do tell the dealership to go **** off they simply go to the computer put your VIN # in turn you into GM and your warrenty gets pulled from GM. Its that simple.
Doubt me? My old dealership I worked for did it with several cars and we even had a couple Cobalt SS/SC that came in that had thier warrenties branded by other dealers so when they came to us we turned them down to.

Don't give advice as to what dealers can and can't do unless you actualy know for sure. I worked for Miller Brothers Chevrolet for almost 4 years and I've seen the **** they do. They will **** you at every turn to get from repairing ANYTHING for free. The easiest way to do it is to go ask BEFORE you mod it, ask the service manager and MAKE sure they won't brand your warrenty BEFORE you do the mod. If your not worried then knock yourself out. But if you are the GMPP stuff is the best way to go. Sure you may be able to get a few extra horses but its not worth it if you break something and they turn you away.

 

Exacly what I was saying... better said though! That is exacly why I went GMPP. I went and asked them and they said it like this, "you get GMPP no worries, you get aftermarket, well then it all depends who is working that day. Some dont give a ****, and some will turn you away" So what did I do, I bought GMPP. The extra few HP just aren't worth the (potential) hassell to me.

 

Just wondering for those that had the extrude manifold installed at a dealer, how long did it take to get installed and what did they charge to install?

 

its supose to be an hours work. Cost depends how much an hour they charge... Should not be over 2 hours labour for sure!1