Finally Dynoed the HHR
Thread Starter
Senior Member
Joined: 03-04-2010
Posts: 458
From: SE Wisconsin
Finally Dynoed the HHR
I put down 257whp/233tq with this set up:
(I think a stock 2.4l puts down 145-150whp)
93 octane 12.0 afr
Ported Eaton m62 3.1" (9psi)
LS4 TB(75mm)
Dual pass/Phenolic Spacer
ZZP cams
Badmab header
ZZP 3" downpipe(no cat)
Stock cat back with Magnaflow muffler
I threw the HHR on a dynojet tonight to help me decide what kind of upgrades I will need to throw at the bottom end this winter. A lot of Cobalt guys have been able to push the 2.4l bottom end to way over 300whp without failures...some over 400whp. I am sitting at 257whp and will be upping the power into the 300whp+ range this winter. Basically I am trying to get this thing to run 12s at the track this spring.
In January I am pulling the head for porting. I will also be running a 2.7" pulley and running e85. Those mods will easily put me above 300whp and get me into the 12/13s range. I just did the dyno as a baseline to help decide if I need to get some forged pistons and rods in this bad boy...Still unsure on that. Doing a job like that would run me about $1500. If the stock bottom end holds up, awesome...if not...I'm out $500 bucks for a junk yard 2.4l and $1500 for internals. I will keep you posted if I decide to go ahead with the build. I am getting some advice from ZZP on this setup. 350whp would be really cool for an m62 build, but we'll see where this project ends up in the spring...And before anyone says go turbo...
I love that whining noise way too much!
And the vid...
http://www.youtube.com/watch?v=W5Pav0RkKMU
Sleeper this is for you. Didn't think I would, but I gave in.
(I think a stock 2.4l puts down 145-150whp)
93 octane 12.0 afr
Ported Eaton m62 3.1" (9psi)
LS4 TB(75mm)
Dual pass/Phenolic Spacer
ZZP cams
Badmab header
ZZP 3" downpipe(no cat)
Stock cat back with Magnaflow muffler
I threw the HHR on a dynojet tonight to help me decide what kind of upgrades I will need to throw at the bottom end this winter. A lot of Cobalt guys have been able to push the 2.4l bottom end to way over 300whp without failures...some over 400whp. I am sitting at 257whp and will be upping the power into the 300whp+ range this winter. Basically I am trying to get this thing to run 12s at the track this spring.
In January I am pulling the head for porting. I will also be running a 2.7" pulley and running e85. Those mods will easily put me above 300whp and get me into the 12/13s range. I just did the dyno as a baseline to help decide if I need to get some forged pistons and rods in this bad boy...Still unsure on that. Doing a job like that would run me about $1500. If the stock bottom end holds up, awesome...if not...I'm out $500 bucks for a junk yard 2.4l and $1500 for internals. I will keep you posted if I decide to go ahead with the build. I am getting some advice from ZZP on this setup. 350whp would be really cool for an m62 build, but we'll see where this project ends up in the spring...And before anyone says go turbo...
I love that whining noise way too much!And the vid...
http://www.youtube.com/watch?v=W5Pav0RkKMU
Sleeper this is for you. Didn't think I would, but I gave in.
Last edited by hhrfreek; Nov 23, 2011 at 07:47 AM.
Thread Starter
Senior Member
Joined: 03-04-2010
Posts: 458
From: SE Wisconsin
The M62 gives you a really flat, consistent torque curve. I held 90% of max torque from 2800 to 6200rpms. With a ported head hopefully I can extend that closer to 7k rpms.
Peak hp was at about 6700rpm. Peak torque around 4700rpm.
If I need to I am going to throw in neutral shafts and rev it out to 7800rpms.
Peak hp was at about 6700rpm. Peak torque around 4700rpm.
If I need to I am going to throw in neutral shafts and rev it out to 7800rpms.
Senior Member
Joined: 10-06-2011
Posts: 1,150
From: Mesa, AZ
He changed cams so that will change the way the motor builds power. This is probably why he has more HP then TQ. Once he ports the head those HP numbers will increase even more then the TQ numbers again.
Senior Member
Joined: 01-13-2008
Posts: 4,708
From: Washington State, where it rains
Far as I know the 2.0 already has forged rods and pistons......and the bottom end was taken up to 740 hp before and problems developed (dyno runs only)..and that was just one piston pin galled up....
Thread Starter
Senior Member
Joined: 03-04-2010
Posts: 458
From: SE Wisconsin
Yeah there are a lot of crazy builds out there on the 2.4l too. ZZP brought one up to 350whp before a rod bent, some have blown cylinder walls before 400whp. I think Hahn had a 2.4l Solstice over 400whp on the stock bottom end as well. I came across some people stating the early 2.4l had forged rods('06) and thats why many of these big builds are holding up. The one thing these builds have in common is they are all turbos. I may not even be able to get near 350whp with the m62.
I am going to wait til after the weekend to make up my mind. I still have a 2.9 pulley to throw back on. My power also started to fall off after 6700 so I am going to ditch the cat back tubing and go with a mandrel bent 2.5". I am hoping the cat back will be worth 10whp at this point. It looks like the stock exhaust gets a bit smaller over the axle too. Then I can record differences in pulley drops as well...I had a lot of fun there. It was my first time around a dyno.
I haven't heard of the LNF being at 740hp though...Maybe the LSJ? I am only wondering because I thought ZZP would have tried to make the most hp on the Ecotec 4's. They made 898whp on an LSJ and the 612whp on an LNF, but they used a modified girdled block on the LSJ. If I recall the issue with the LNF is getting enough fuel with direct injection as there are no other injectors available.
I am going to wait til after the weekend to make up my mind. I still have a 2.9 pulley to throw back on. My power also started to fall off after 6700 so I am going to ditch the cat back tubing and go with a mandrel bent 2.5". I am hoping the cat back will be worth 10whp at this point. It looks like the stock exhaust gets a bit smaller over the axle too. Then I can record differences in pulley drops as well...I had a lot of fun there. It was my first time around a dyno.
I haven't heard of the LNF being at 740hp though...Maybe the LSJ? I am only wondering because I thought ZZP would have tried to make the most hp on the Ecotec 4's. They made 898whp on an LSJ and the 612whp on an LNF, but they used a modified girdled block on the LSJ. If I recall the issue with the LNF is getting enough fuel with direct injection as there are no other injectors available.
Platinum Member
Joined: 01-09-2007
Posts: 16,081
From: SE USA
hhrfreek-
"I came across some people stating the early 2.4l had forged rods('06)"
Info posted long ago by ChevyMgr (2009) stated the 2.4l rods are forged C70 steel, & that was for the 08 model year, + that was a carryover feature from previous years.
Also have piston oiling jets aimed at the underside of the pistons for cooling..
Like the twinkee Harleys..
Crankshaft is stroked nodular iron..
The 2.4l VVT Gen ll block has strengthened bulkheads also..
I printed the whole page..
"I came across some people stating the early 2.4l had forged rods('06)"
Info posted long ago by ChevyMgr (2009) stated the 2.4l rods are forged C70 steel, & that was for the 08 model year, + that was a carryover feature from previous years.
Also have piston oiling jets aimed at the underside of the pistons for cooling..
Like the twinkee Harleys..
Crankshaft is stroked nodular iron..
The 2.4l VVT Gen ll block has strengthened bulkheads also..
I printed the whole page..
