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Just bought a used VQ37 awd engine from a yard off a 2013 G37x that I am currently stripping down to just the block to be machined and freshened up.
I plan on getting Wiseco forged piston heads with Brian Crower rods and I'm wondering if I should over size the piston heads.
The reason I ask is not because I want to increase the displacement but instead because I read after getting the cylinder walls machined they could be shaved down during the cleaning process, so I'd like to keep a low compression ratio for the AAM twin kit I have while also making sure the pistons are going to fit properly.
Any help and information will be greatly appreciated so thanks in advance.
Stock ECU and ecutec or standalone?
either way, low compression should NOT be your goal.
besides, a "cleanup" or even oversized (stock) pistons would not change the comp ratio enough to sooth detonation issues prevalent with past fuel/timing management.
and don't bother "cleaning" the bores till you have new pistons in hand for the machinist to measure.
if your power goals are high enough, sleeving and/or a block guard might be the way to go.
Stock ECU and ecutec or standalone?
either way, low compression should NOT be your goal.
besides, a "cleanup" or even oversized (stock) pistons would not change the comp ratio enough to sooth detonation issues prevalent with past fuel/timing management.
and don't bother "cleaning" the bores till you have new pistons in hand for the machinist to measure.
if your power goals are high enough, sleeving and/or a block guard might be the way to go.
Sorry I didn't get back sooner, I haven't had time to comeback to this thread till now.
To answer your questions I'll be keeping a stock ECU with ECUcutek as I haven't found a standalone ECU for the G37 anywhere I've tired looking. My power goals I'd say are fairly high (roughly 600hp to the wheels). I do intend on sleeving my block with Daton sleeves aswell as using the Wiseco/Eagle pistons and rods
I wasnt too sure on what a "good" compression ratio for boost would be and I am still fairly new to anything in depth like that, I figure the normal 10:1 would be ideal for boost but I really am unsure.
The only reason I thought I may need to oversize the cylinder walls wasn't from a want to do so but rather it may have to happen during a cleanup if the engine has alot of debris or carbon build up inside the block, Im sure alot of the VQs by now (atleast any I can buy used) have really seen better says and have seen many many miles. My plan is to buy a X model longblock with the transmission and tear it all apart by hand to learn the ins and outs while also saving money instead of buying a remanufactured VQ from somewhere.
Hope that answers some of your questions and give you a better idea of my plans, anymore help will be appreciated.
But it focuses on NA and the 12:1 JWT pistons would not be a suitable fit for boost on pump gas based on my understanding.
Personally, if I were pursuing boost, I would lean on the manufacture/install shop/tuner of the supercharger or turbo for compression ratio recommendations.
Sorry I didn't get back sooner, I haven't had time to comeback to this thread till now.
To answer your questions I'll be keeping a stock ECU with ECUcutek as I haven't found a standalone ECU for the G37 anywhere I've tired looking. My power goals I'd say are fairly high (roughly 600hp to the wheels). I do intend on sleeving my block with Daton sleeves aswell as using the Wiseco/Eagle pistons and rods
I wasnt too sure on what a "good" compression ratio for boost would be and I am still fairly new to anything in depth like that, I figure the normal 10:1 would be ideal for boost but I really am unsure.
The only reason I thought I may need to oversize the cylinder walls wasn't from a want to do so but rather it may have to happen during a cleanup if the engine has alot of debris or carbon build up inside the block, Im sure alot of the VQs by now (atleast any I can buy used) have really seen better says and have seen many many miles. My plan is to buy a X model longblock with the transmission and tear it all apart by hand to learn the ins and outs while also saving money instead of buying a remanufactured VQ from somewhere.
Hope that answers some of your questions and give you a better idea of my plans, anymore help will be appreciated.
I'll definitely have to give that a deeper look for some info. As of right now I'm in talks with AAM to make a TT kit for the X model Gs since we don't really have anything besides SC to have fun with and i prefer turbo whistle to a belt whine..
From what I do remember reading on AAM's website is they recommend a lower compression ratio and they also use Wiseco pistons and rods in their create engine options, but I still have no idea what cylinder bore they are using, it could be the factory 95.5mm or it could be something like 96.5mm, I'm really not sure. I really wanna go in depth and do a full engine rebuild myself to learn the ins and outs of the VQ37 without blowing it up once I put it back in.
I figure having a slightly bigger cylinder bore may provide a little bit of extra power but all I wanna do is have the walls cleaned up since the TT kit will already provide more than enough power. I guess ill have to wait until I hear back from AAM on what they recommend.
12-14-2023, 05:28 AM
