Does anyone know if the gmpp extruded honed exhuast manifold will fit the hhr or no, specifically the 2.4L ?

GMPP is just a Extrude Honed version of the stock cast iron manifold. I know the guys on www.cobaltss.net are using these on the 2.2 cars but you would have to check and see about the 2.4.... I am pretty sure they would fit since the headers put out by most companies are fitting BOTH the 2.2 and 2.4.... So your chanced are VERY good that it will fit!

well, i dont know if it does, or if the hhr's exhaust is setup a tad different than the cobalts, but im gonna go ahead and be the test dummy and try it out, i hope it fits, the cobalt ss guys claim they get 4-6whp and 4-5w trq, i guess every little bit helps eh...

if it is fitting the 2.2 it will not fit the 2.4 the flange that bolt's to the cat. is different just my 2 cents

if it is fitting the 2.2 it will not fit the 2.4 the flange that bolt's to the cat. is different just my 2 cents

Any evidence to back up this claim, there's numerous people on the cobaltss.net forum that have put the gmpp manifold on there cobalts.

Any evidence to back up this claim, there's numerous people on the cobaltss.net forum that have put the gmpp manifold on there cobalts.

I think if you poke around the forums and look at the pics, there are some fundamental differences between the two engines in the HHR.

i say just do it and let us know only sure way.

well, i dont know if it does, or if the hhr's exhaust is setup a tad different than the cobalts, but im gonna go ahead and be the test dummy and try it out, i hope it fits, the cobalt ss guys claim they get 4-6whp and 4-5w trq, i guess every little bit helps eh...


:poke: :poke: Do it...

If your gonna get one, don't miss out on the group buy!
http://www.cobaltss.net/forums/showthread.php?t=32085

Spend 250 for a maybe.....not seeing it happen!

Spend 250 for a maybe.....not seeing it happen!

Ahh hah, such is the beauty of working at a gm dealership, discount out the wazoo and i know the parts guy....yay for me lol !

Well if you get it and it doesn't work let me know and I may know a couple people to take it off your hands! :D

Well if you get it and it doesn't work let me know and I may know a couple people to take it off your hands! :D

Will do, but im pretty sure it'll fit. Im gonna order it monday, but i dunno if its on back order or anything weird. Just the other day i tried to order some all weather floor mats for the rear, and they were on back order, i was like u gotta be shitting me. So i dunno, well see, ill update as soon as it gets in

From dealing with past Cavaliers and Cobalts I dont think the 2.2 and 2.4 are the same. It might line up close but then have a slight leak. I say dont do anything halfass on this nice ride and just wait for them to come out with a model that is meant for it.

Ok, ill try to explain this clearly as possible. The cobalt and HHR share the same engine, 2.2/2.4. Now if people on the cobaltss.net forum are putting the gmpp manifolds on their 2.4's with no problems and making more power with them, i will have no problem doing the same to my hhr, same engine, both have the same manifold design. I feel like im getting bashed for thinking of this ? First of all im being the test dummy for everyone, so gimme a break, and second, why are yall making such a big fuss over this, its my car, my money, im postitive it will work, if not ill tell yall so yall can make fun of me alright, good day !

Ok, ill try to explain this clearly as possible. The cobalt and HHR share the same engine, 2.2/2.4. Now if people on the cobaltss.net forum are putting the gmpp manifolds on their 2.4's with no problems and making more power with them, i will have no problem doing the same to my hhr, same engine, both have the same manifold design. I feel like im getting bashed for thinking of this ? First of all im being the test dummy for everyone, so gimme a break, and second, why are yall making such a big fuss over this, its my car, my money, im postitive it will work, if not ill tell yall so yall can make fun of me alright, good day !


dhbguy... sent me an email , I have some info for you... the internet has ears... :lol:

he said good day! and go for it i feel ya and when it work let me know =)

No one is bashing you at all. We are just giving advice. As I have delbt with Chevy Engines for tons of years now, I know the engine of the 2.2 is not exact to the 2.4. Hence there is gonna be a little difference. The Cobalt Engine people are also going to be trying like you since I have seen the 2 Cobalt Engines Side by side at meets and they ARE slightly different.

Uncivil... then why are the part numbers for the GMPP manifold just listed as Cobalt? If there was a difference between the mounting on the actual head itself wouldn't there be some kind of notation or selection? I actually hang out with a few Cobalt owners here in Tucson. 1 2.2, 2 2.4 and 4-5 2.0SC's. Almost everything is the exact same. One of them being the Mani's. They all bolt to the same cats but the downpipe section and cat back are different sized. The 2.4's have a 2.5" system to the axle then chokes to 2.25. The SS/SC look to be 2.5 Cat to tip. D... I say GO for it. If nothing else I do know a couple of these Cobalt guys will take it. GOOD LUCK!!:thumb:

Ok, ill try to explain this clearly as possible. The cobalt and HHR share the same engine, 2.2/2.4. Now if people on the cobaltss.net forum are putting the gmpp manifolds on their 2.4's with no problems and making more power with them, i will have no problem doing the same to my hhr, same engine, both have the same manifold design. I feel like im getting bashed for thinking of this ? First of all im being the test dummy for everyone, so gimme a break, and second, why are yall making such a big fuss over this, its my car, my money, im postitive it will work, if not ill tell yall so yall can make fun of me alright, good day !

I hear ya and support what your doing. It's folks like us that often set the groundwork for others to follow. If I had a dollar for every idea I had over the years that someone told me not to try, I'd be a rich man. But at the same time I would have missed out on a ton of successful experiments and the pleasure of seeing the fruits of my labor turn out to be a GREAT thing.

So are you going through with it? and if so when can we expect a thumbs up or down?

So are you going through with it? and if so when can we expect a thumbs up or down?

Read dnbguy86 new thread, http://www.chevyhhr.net/forums/showthread.php?t=4729 .

doesn't say if he has the manifold on or not

Yeah, about the manifold. Apparently, itll be like another week for it gets here. No place in my area has this part, or even gm accessories for that matter, sorry to the inconvience again, hopefully soon it shall be here.

O ok more so of my questions is if you went through with it dispite the Criticism but good to know that in 2 weeks or so i might have another mod available to my disposale

and why aren't we using these i was reading on cobaltss.net n they have a couple headers out there for the cars n some others coming out?
http://www.zzperformance.com/cobalt_ion/products1.php?id=543

My bad :red: , he has the GMPP exhaust not the manifold.

Does anyone know if the gmpp extruded honed exhuast manifold will fit the hhr or no, specifically the 2.4L ?

Just remember you heard it here..
Yes.. if fits a 2.4 HHR...

are you sure of that Hvrod cause if so then hey dnbguy you wanna get in on that group purchase from cobalt if its still going on?

http://i37.photobucket.com/albums/e72/hvrodpics/Oldexhaust.jpg

Yes..
I've tested fitted to my HHR....

Heres the stock one.. off of Mine..

according to the cobalt people the GMPP exh mani will fit all the engines. the exh mani's are universal among the 3 engines and people with 2.0 Sc's are selling they're stock systems to 2.2 guys to put on since they are bigger and free-er flowing. However the GMPP mani is NOT... i repeat is *NOT* a header. It is an extruded stock manifold. As stated on a cobalt forum... "anyone with a decent dremel and a free weekend could do the same thing..." You could get the same gains by port matching the stock mani to your head and making all the passages bigger in general. It would just be time consuming.

http://www.cobalt-addiction.com/performance.htm

What about this if all the manifolds/headers are interchangable??? what a deal?

http://www.cobalt-addiction.com/performance.htm

What about this if all the manifolds/headers are interchangable??? what a deal?


No doubt... I wonder if that would work. If I had a conversation with them first, and make sure I could return it if it didn't fit. They might be willing to do that to put on they're site that it fits an HHR as well

i sent them and email hopefully you did as well so they get the hint there is a market out there any maybe we got some cheap headers for our cars would be nice

It will fit our cars are the same as the cobalts. Headers will fit either car. We actually have a little more room between the engine and firewall than the cobalts do. The top of our firewall just bend in more. If you saw the 2 side by side you would understand more fully what I am talking about.

yea i would i really haven't even took that close of a look at my car but with your "ok" its like a guy in a white coat saying take this you'll feel better i am all over it then cause you can't beat 200.00 for stainless steel. Also do you know if our cars have the egr n how sensitive our cars or the cobalts are if we ran these headers are we going to through codes?

Well then I guess the Forced Induction Kits must be interchangeable as well.....

how do you figure when our comps are diff, intakes, and clearing in front? i Mean we can do the headers n so on and pulleys and alot of other things but not everything.

computers are the same for the Cobalts and HHR's too. Turbo kits won't go back and forth cause the front half of the engine bays are different. If you look ours starts wide at the firewall and bows in to the grill. the cobalts are just square. the only prob with cobalt turbo kits would be piping for the intercooler.

Uncivil... these cars do not have egr's anymore. There has been a long discussion on this with the cobalt guys over the 2.2's especially. Some of the 06 and above Cobalts have an air injection that takes air from the intake to put into the head or warm air from the head to heat the intakes. They aren't quite sure yet. But it has been said that NONE of the new ecotec engines do NOT have egr valves anymore. Do to some of the emissions components on the ecotec engines it is not necessary to have one. We have come a long way in emissions control in the last few years.

any one know were we can get some pulleys zpec's web site is down and i can't seem to find another site only pulleys for the sc 2.0 sorry i know off topic but i dont want to start another thred.

Just wondering about this.....

Does anyone KNOW if there is an advantage in horsepower and/or torque gain from doing this???? I mean, just because it works on a 2.2 and it fits on the 2.4 doesn't necessarily mean an advantage....valve sizes are different, port sizes....well you know the rest. Maybe the OEM manifold already took that into consideration when it was designed, for the increase/difference in HP.

Kind of reminds me of some things done in the "muscle" car years and found out that the cost was not worth it (1 or 2 HP for $200-$300).

Just asking because everyone is talking but nothing is documented.

Most of the gains for something like this on a "4 banger" are going to be minimal of course. However the Cobalt forum guys are running all GMPP parts so they don't void their warranties. More flow is more flow. I imagine the port sizing from 2.0-2.4-2.2 would be minimalistic at best. Especially since this is a universal piece. The only difference I have see is the 2.2 are running 2.25" to 2.5" exh... the 2.4 are runnin 2.5" only, and the 2.0 are running 2.5" and even 3" piping! Someone has to be a tester somehow and if no one else will post gains and such I am going to try and get some dyno time in here in tucson and even some track time and see what comes of this.

any one know were we can get some pulleys zpec's web site is down and i can't seem to find another site only pulleys for the sc 2.0 sorry i know off topic but i dont want to start another thred.


Pulleys have been made for the cobalts and some have tried using on a 2.2 and 2.4 but nothing "officail" from the guinea pigs yet. AEM makes an underdrive pulley and a lightened alternator pulley. The other thing they are trying is taking the pulleys from older ecotecs like the cavaliers and trying them. Still no word yet. You might check www.ecotecforum.com and ask around. They could help with your answers too. They ONLY discuss the motors!

well they will have the actual dyno reports soon on this new header i am buying as for the gmpp manifold there are alot of times/dyno's backing that up. As far as the manifolds being the exact same they are not because from my research the 2.0's are slightly larger then then 2.2's not even enough to compare with the 2.4L. But the 2.0 guys are replacing with gmpp manifold then selling the old manifolds cheap to the 2.2 guys so once again we need people's testements to back things up and i am willing to try things out

so i will not notice anything on my extrude honed i took off my SS/SC balt when I traded it in? I thought it may work and yes I know this is an old article but I am a newer owner and did use search :D

according to some of the people here. the extruded honed is just the normal one with the p/n shaved off. will you notice anything, maybe but probably not.

cool was wondering had it laying around. if it is not worth the effort to do it i am not doing it...lol