Ok once again i dont own a cobalt i own a 2.4L 5spd HHR and from what i understand we can use your headers,manifolds etc.. we even have more room between them and the firewall from what i hear. now on to my questiions

1. are there any leak issues
2. do they throw codes
3. do you recomend a certin gasket
4. any numbers dyno perfer time slips with them on 2.4Ls
5. all comments good bad the ugly welcome

 

Well, I just installed mine today. The installation went ok, except that I broke off 2 of the 3 rear flange studs on the stock manifold trying to get them loose. I don't know what kind of thread lock the factory uses, but they might as well have welded the old nuts on. All hardware was included, except for the new nuts. A quick scrounge around the garage and I was good to go - no harm, no foul.

The gaskets they sent are very thick, match the header perfectly and work great - no leaks on the first try. One of the head nuts was pretty close to the tube and required an open end wrench to put it on, but the rest went like clockwork - almost a little too easy.

When I received the header I noticed that it could use a little porting work (a little rough at some welds inside and a little overhang inside the collector by the rear ring), so I grabed a couple stones and a flap wheel, took out the die grinder and went to work. After the inside was glass smooth - a couple hours later - I slipped it on. Yeah, they could have polished it themselves, but for $200 what do you expect?

I don't know why they bothered to paint a stainless header, cause the paint started to burn off almost immediately. This was a totally unnecessary waste of time and money IMHO.

Ok, performance wise (drum roll)... I love it! Lots of low end on my 2.4. The revs climb faster, with less throttle. It's like the engine wants to run faster. It's only slightly louder than before - mostly when you punch it (I have a corsa touring cat-back). I sorta expected it to be louder.

Oh, did I mention that the engine is buttery smooth - notcably less vibrations than stock. I guess those equal length tubes equalized the power output from each cylinder.

Yes, the butt dyno tells me there is plenty more power (but I've got a Westers tune that I asked them to tune for a header). Even if there wasn't a huge hp gain, the smoothness in the running alone would make it worth it for me. The car just feels more refined now - it's hard to explain, but I love it! There's a nice weight savings too - the old cast iron manifold was a boat anchor. BTW, no CEL so far.

I'm going on vacation soon, but when I come back I plan on getting it dyno tuned. I'll post up the results then.

Overall, I think it's the best $200 a spent since I got my Injen CAI.

 

Thanks i was wondering mostly about fitting issues like bolts to use if they come with some locking ones etc...and if the gasket is a piece of **** like cork or something like that. well thank you for your input looking forward to get mine very very soon.

 

good review. I'm either going with this shorty and a dp or weapon R's long tube.

 

I love mine too.,.. supposedly they are a 10hp gain on the 2.4's which they were originally tested on... I can't wait to get my car on the dyno saturday

 

which header was this? was it a gmpp or something else?

 

cobalt-addictions...