Finally..
Senior Member
Joined: 10-19-2011
Posts: 1,553
From: N.Y.
18 to 19 I thought the gmtu was a little higher but I could be wrong.
Sounds like they do have a mind of their own.kind of like making a doctors appt then you feel better by the time the appt arrives.
I am wondering if yours some how just took time to relearn the changes.
I believe I read somewhere where ssfan posted that sometimes after a tune change the car needs to be started a couple times before the tune changes work but that was on a hptuner setup
Sounds like they do have a mind of their own.kind of like making a doctors appt then you feel better by the time the appt arrives.
I am wondering if yours some how just took time to relearn the changes.
I believe I read somewhere where ssfan posted that sometimes after a tune change the car needs to be started a couple times before the tune changes work but that was on a hptuner setup
Senior Member
Joined: 02-19-2012
Posts: 1,015
From: Northern California
18 to 19 I thought the gmtu was a little higher but I could be wrong.
Sounds like they do have a mind of their own.kind of like making a doctors appt then you feel better by the time the appt arrives.
I am wondering if yours some how just took time to relearn the changes.
I believe I read somewhere where Breadfan posted that sometimes after a tune change the car needs to be started a couple times before the tune changes work but that was on a hptuner setup
Sounds like they do have a mind of their own.kind of like making a doctors appt then you feel better by the time the appt arrives.
I am wondering if yours some how just took time to relearn the changes.
I believe I read somewhere where Breadfan posted that sometimes after a tune change the car needs to be started a couple times before the tune changes work but that was on a hptuner setup
Platinum Member
Joined: 12-06-2009
Posts: 11,721
From: Alabama
18 to 19 I thought the gmtu was a little higher but I could be wrong.
Sounds like they do have a mind of their own.kind of like making a doctors appt then you feel better by the time the appt arrives.
I am wondering if yours some how just took time to relearn the changes.
I believe I read somewhere where ssfan posted that sometimes after a tune change the car needs to be started a couple times before the tune changes work but that was on a hptuner setup
Sounds like they do have a mind of their own.kind of like making a doctors appt then you feel better by the time the appt arrives.
I am wondering if yours some how just took time to relearn the changes.
I believe I read somewhere where ssfan posted that sometimes after a tune change the car needs to be started a couple times before the tune changes work but that was on a hptuner setup
Senior Member
Joined: 10-19-2011
Posts: 1,553
From: N.Y.
I understand what you have heard and what you are saying.
I totally understand Boost.It is a measurment of back pressurein some ways.
Bolt on a junk set of exhaust manifolds or a super restrictive muffler on a supercharged car and see how much boost you make a lot but not a lot of power.
I have Been dealing with supercharged and nitrous cars for quite some time now.I admit still learning on the turbos and fuel injected cars and you guys are a great help.
I guess the only real way to see if anyone is actually making the 290 hp is to put it on a dyno or run it at the dragstrip. Which most will not do.
With my most current setup on my drag street car I am making the same amount of boost but I went from a .485 lift cam to a .625 lift cam
I also went from a 2.02 intake valve to a 2.08 intake valve
heads 180 cc runner to 220cc runners.Add about 40 cubic inches to the motor also
Car picked up approx 150-200 HP
Same Boost
But seeing how the HHR's are the same cars same transmissions etc. I am not seeing where a car with 19 psi will make any where near the power that a 25 psi car will make with the same tune.
If gm is saying that the stage one will make 290 hp with 18-19 psi that is fine.
Just be nice to see it on a dyno or dragstrip with exactly that boost.
Of course if what you are saying is correct and the others who are claiming to be making more boost and are not then I can see what is going on here.
I always get a kick out of the younger crowd who comes over at the strip and says how much boost ya running? and depending on the tune I will say 14 or so they then tell me they are making 20 plus with theres and just assume that if you have more boost you are faster until they run and then see what a car that adds over 400CID of are per revolution can do with 14 psi.
I totally understand Boost.It is a measurment of back pressurein some ways.
Bolt on a junk set of exhaust manifolds or a super restrictive muffler on a supercharged car and see how much boost you make a lot but not a lot of power.
I have Been dealing with supercharged and nitrous cars for quite some time now.I admit still learning on the turbos and fuel injected cars and you guys are a great help.
I guess the only real way to see if anyone is actually making the 290 hp is to put it on a dyno or run it at the dragstrip. Which most will not do.
With my most current setup on my drag street car I am making the same amount of boost but I went from a .485 lift cam to a .625 lift cam
I also went from a 2.02 intake valve to a 2.08 intake valve
heads 180 cc runner to 220cc runners.Add about 40 cubic inches to the motor also
Car picked up approx 150-200 HP
Same Boost
But seeing how the HHR's are the same cars same transmissions etc. I am not seeing where a car with 19 psi will make any where near the power that a 25 psi car will make with the same tune.
If gm is saying that the stage one will make 290 hp with 18-19 psi that is fine.
Just be nice to see it on a dyno or dragstrip with exactly that boost.
Of course if what you are saying is correct and the others who are claiming to be making more boost and are not then I can see what is going on here.
I always get a kick out of the younger crowd who comes over at the strip and says how much boost ya running? and depending on the tune I will say 14 or so they then tell me they are making 20 plus with theres and just assume that if you have more boost you are faster until they run and then see what a car that adds over 400CID of are per revolution can do with 14 psi.
Senior Member
Joined: 10-19-2011
Posts: 1,553
From: N.Y.
Darn You just summed up what took me a few minutes to type
Wish I would have summed it up that way.
Wait a minute Father that actually sounds like a nice saying for a bumper sticker or tshirt.
I might have to use that one
BOOST IS Nice But Flow Is Better!
Wish I would have summed it up that way.
Wait a minute Father that actually sounds like a nice saying for a bumper sticker or tshirt.
I might have to use that oneBOOST IS Nice But Flow Is Better!
Senior Member
Joined: 02-29-2008
Posts: 838
From: Oak Creek, WI
Yet another example of why i will stay stock w/ our '08 SS, 'cos folks get these GM turbo upgrade kits or some other tune & they start crying after awhile.
Stock= No tears.
Tune= Would you like some Kleenex ?
Stock= No tears.
Tune= Would you like some Kleenex ?
Senior Member
Joined: 02-29-2008
Posts: 838
From: Oak Creek, WI
but it does work like it's supposed to 100% of the time. 
