Need some help fellas.....I recently installed a stock gsr head onto my built ls bottom end. Previous setup made 373whp on pump gas so I'm expecting the new head to make close to 450whp? We just started the car up today and a/f's are in the mid to high 11's all the way up to 8k. My problem is the car is seriously lacking power and doesn't rev nearly as quick as my ls did??? Yes, vtec is engaging at 4500 but it feels like the car is just dying out at 7k and doesn't want to rev any higher?? I have a stock gsr intake manifold on it with the butterflys removed. Could it also be a vacuum leak cuz I'm pretty sure I have one from the fuel injectors to rail. The rail isn't sitting flat on the gsr manifold for some reason that's why it's leaking but would that cause a serious power loss? Thanks guys...all input appreciated!! Ryan

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Teglove2 &raquo;</TD></TR><TR><TD CLASS="quote">Need some help fellas.....I recently installed a stock gsr head onto my built ls bottom end. Previous setup made 373whp on pump gas so I'm expecting the new head to make close to 450whp? We just started the car up today and a/f's are in the mid to high 11's all the way up to 8k. My problem is the car is seriously lacking power and doesn't rev nearly as quick as my ls did??? Yes, vtec is engaging at 4500 but it feels like the car is just dying out at 7k and doesn't want to rev any higher?? I have a stock gsr intake manifold on it with the butterflys removed. Could it also be a vacuum leak cuz I'm pretty sure I have one from the fuel injectors to rail. The rail isn't sitting flat on the gsr manifold for some reason that's why it's leaking but would that cause a serious power loss? Thanks guys...all input appreciated!! Ryan</TD></TR></TABLE>

wouldnt u also be leaking fuel then? if the fuel rail didnt seal...??

 

Not leaking fuel just air..........bump for a guy who needs some help

 

check your timing for a vacum leak just start the car and get some brake clean over the intake manifold

 

from the fuel injectors to the rail would leak fuel.
From the injectors to the manifold would leak air and or fuel.

Anyway check for vac leaks , did you do a retune yet?
Are you %10000000000 sure your timing is on point this time?

 

I would question timing. If you have a steady AFR the vacuum leak isnt making a difference at WOT.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nonvtecD &raquo;</TD></TR><TR><TD CLASS="quote">I would question timing. If you have a steady AFR the vacuum leak isnt making a difference at WOT.</TD></TR></TABLE>

I would too becuase I know the mistake was made on that car before.

Ryan double, triple , quadruple check the dist timing and cam gears and crank pulley again and again and again until you are %1000000 sure its correct, then take it to a tuner to retune it.
You slapped on a totally different head, with different flow characteristics and diff IM and such. Dont expect the tune to be on.
And dont expect becuase the AFR is on that the car is running right and tuned correctly.

 

Not trying to be a dick Pete but I know. And yes the timing is ON.....we double, triple checked it to make sure it is on.......What doesn't make sense is that this head flows MUCH better than a ls head so why don't the a/f ratios changing? Still using ls map for fuel/timing and the car is staying consistently in the 10/11 a/f ratios? Timing at 13psi is about 13.5degrees and at 18psi is at 11.8 degrees....thanks for your help guys!

 

bump.....

 

I still think that timing is crazy
Anyone else see anything wrong with that possibly?

Why not have the tuner look at it again? Better safe then sorry man.
Did you use a new Intake Manifold gasket?
Sure all the gaskets are sealing correctly?
Did youdo the valve clearances on the head? That will make a HUGE difference.

 

so you got retuned after putting the vtec head on right?

 

NO . he is jsut going by his wideband readings since he put the head on.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dunc &raquo;</TD></TR><TR><TD CLASS="quote">so you got retuned after putting the vtec head on right? </TD></TR></TABLE>
ITs a good idea, yes.

 

Brian, I haven't had it tuned yet cuz I keep having problems with it. I can't get it retuned til it's good to drive. It's leaking coolant from the coolant passage on the intake cuz i used hondabond instead of a gasket and I paid the price. I'm waiting for my new hpracing sheet metal intake manifold to arrive and I got a REAL gasket coming so......my concern is that why wouldn't the af's change when I put the vtec head on, it makes no sense? O, Pete, the valve clearances were double checked. Intake is .007 and exhaust is .008......

 

Well since you didnt use a gasket that could possibly be the problem.
You prob have all kinds of Intake leaks.
Why 1/2 *** it to get it running with the stock IM when you are just going to replace it right away? Its not like you NEED to drive it.
Dont be in a rush man. Look where its been getting you.