View Full Version : What kind of compression should i be running on boost??
your_buddy_eliot
01-08-2015, 12:13 AM
Hi guys, I'm new to YW and i was looking for some advice. So i've got an '08 Yaris sedan with about 63000 miles. Bone stock. bought the car from my sister before she moved away. I've decided i wanted to go boost after i hit about 115, and felt that the transmission could hold a lot more power (automatic). I already know what kit i have to run, and have downloaded all the "how to boost you're yaris" pdf's from here and all that semi-obvious stuff if you know what to look for when boosting. BUT what i want to know is will the yaris be able to hold boost with my kind of milage. I was thinking maybe it could hold no more then six pounds on factory internals, but I'm just pulling these numbers out of my ass really. All that has ever been put in the car is regular 87 octane. Second, i was reading up on the CP pistons and noticed they're 11.5:1 compression. My dream is to hold 17 pounds of boost, but from my knowledge of how turbo's work, that's just too high of a compression rating. I was aiming for 8.5:1 compression. If anyone can help me out with a set of pistons/rods that would fit this range, i'd really appreciate it :smile::smile::smile::smile::smile:
ilikerice
01-08-2015, 05:29 AM
If you keep looking in this part of the forums, you will see that the 1nz can hold about 8psi (if tuned properly) on stock internals. People suggest anything after that the rods are the weakest point. Surprisingly, the pistons are pretty damn strong on the motors, and the cylinder walls are really thick so sleeves are a waste of money. If you are trying to stay under 15psi, I don't think the low compression pistons are needed. Someone else can shine a brighter light on that subject, but if you plan to go bigger later on, then if you are swapping out rods, might as well do pistons if your budget will let you.
Whats your HP goal? that would determine what you will need to upgrade
CP also make forged 9:0cr in standard or.5mm oversized, i think Garm ran CP 9.5cr correct me if I'm wrong. you can always make a custom order to your own specs aswell.
your_buddy_eliot
01-08-2015, 12:07 PM
I'm looking to get 250 to the wheels. all boost. Then maybe add a fifty shot if im not slaying subaru's yet.. lol. I think running 8 psi might get me in 160 range if properly tuned. i figured it would be safer to knock everything out in one go, rather then boosting factory pistons then yanking everything out to replace them when i want more boost. @ilikerice
do you know what part number those are? i looked everywhere online and it kept popping out with the CP Pistons that do 11.5:1 @corb
ilikerice
01-08-2015, 03:25 PM
http://www.yarisworld.com/forums/showthread.php?t=32747
this tread is pretty informative, even though its old, still a good collective amount of information gathered here.
To answer one of your original questions,
will the yaris be able to hold boost with my kind of milage.
If you are going to go ahead and do everything while it is torn apart, this question shouldn't even be a on the table. If you are looking for low compession pistons, you will need new rings anyways, and while the head is off, might as well replace your valve stems. And if you are going that far, get a head and block rebuild kit with all new gaskets, they run about $200-$250ish.
Pistons are not cheap for toyota's. Don't know why, they just are. Honda pistons are half the price. Supply and Demand I assume.
Call Garm up from MicroImage and get some quotes, even though he doesn't list things on his website, doesn't mean he can not get them at a good rate. I think he will price match also, but don't quote me on that. His customer service has no equal.
ilikerice
01-08-2015, 03:26 PM
Yes, Garm was running 9.5:1 CP pistons
http://www.microimageonline.com/Yaris4Sale.html
your_buddy_eliot
01-08-2015, 04:39 PM
Thank you big time bro ! i really appreciate all the help !.. It's gonna take me a while to get this project done but hopefully YW is still gonna be active :big grin: @ilikerice
ilikerice
01-08-2015, 06:09 PM
I come and go... But the usual people are here CTscott is really helpful with anything that touches a wire in a yaris.. he got all sorts diagrams and gadgets.
Don't get too discouraged if you dont get a response within a day or 2.. either the right people are not on that week or we are all stumped..
Found these on Amazon today.
http://www.amazon.com/CP-Pistons-Forged-Toyota-75-5mm/dp/B0036O7BL8/ref=sr_1_fkmr0_2?ie=UTF8&qid=1420972352&sr=8-2-fkmr0&keywords=Amazon+1nzfe+cp
I'd buy through microimageonline though, shoot them a email.
I running cp 9:1 .5mm over bore with Molnar rods and holding boost well.
Blown_xa
01-13-2015, 10:03 PM
CP will send you any compression desired, but 9:1 and 11.5:1 are what they offer (off the shelf). I would recommend BC Sportsman rods along with. Im currently running the 9:1 , running 29psi. I was going to run higher compression and tune with e85 for a nice power band, but e85 is just too hard to come by here.
Stock motor doesn't have a boost limit, it has a power limit. for example, on my set-up (room-mate has my/ PTUNING kit) on a stock motor.... it reached 160whp at a mere 3.5psi.
CrankyOldMan
01-13-2015, 10:42 PM
Stock motor doesn't have a boost limit, it has a power limit. for example, on my set-up (room-mate has my/ PTUNING kit) on a stock motor.... it reached 160whp at a mere 3.5psi.
Where do I get in line for said horses?
Blown_xa
01-15-2015, 10:49 PM
Where do I get in line for said horses?
for the kit? We produced one batch of the manifolds, but seeing as though it took 2 years to sell 5, we have no intentions on producing a kit. We can do one -off if car is dropped off. kit is about $6000 installed and tuned. Found old thread on Scion life... http://www.scionlife.com/forums/scion-xa-xb-1st-gen-forced-induction-1644/ptuning-1nzfe-turbo-system-xa-xb-215013/
CrankyOldMan
01-16-2015, 06:53 AM
Insert thread hijack!
Interesting read. I've already done a handfull of bolt-on mods, and I'm looking at a fairly major upgrade in the near future. Current options on the table include removing the Blitz S/C and installing a turbo, twincharging with the Blitz and a turbo, a 2ZR-FE swap, or a 2ZR swap with boost. I'm looking to get around 200 whp, so this kit looks like a solid contender.
your_buddy_eliot
02-03-2015, 11:55 PM
I was able to find your Xa on youtube. Need to say that is maaaaad awesome. So the PTuning kit is completely fabricated by you guys? or is it a specific aftermarket turbo (i.e. Garret, Turbonetics etc) with a tune that you guys ran? because getting up to 160whp on 3.5psi sounds like straight up witchcraft lol.
PS, sweet ride
Blown_xa
02-05-2015, 07:42 PM
I was able to find your Xa on youtube. Need to say that is maaaaad awesome. So the PTuning kit is completely fabricated by you guys? or is it a specific aftermarket turbo (i.e. Garret, Turbonetics etc) with a tune that you guys ran? because getting up to 160whp on 3.5psi sounds like straight up witchcraft lol.
PS, sweet ride
the turbo itself is a t3 60trim Garrett. The rest is all fabricated. The turbo manifold was the key factor on making it efficient.
fnkngrv
02-05-2015, 11:56 PM
I can attest to how important the turbo manifold is. That being said Garm was able to hold 24psi with a log style manifold without issues. I am making some changes to my setup the first few months of this year in hopes of relieving an air flow bottleneck, cooling issue, and overall performance.
your_buddy_eliot
03-14-2015, 01:23 AM
With that being said, i was looking at a Weapon R 4-2-1 Header, and a Weapon R Aluminum intake manifold and slapping on a 1zz throttle body. going with a Garett T3 (I can probably score a used snail for $200 and a rebuild kit for $70), i think i can rig it onto the Weapon R header, i might just have to fabricate a flange to fit the turbo onto there, but this is just theory. You think that header and that intake manifold would be enough to satisfy say 15psi?
vBulletin® v3.8.11, Copyright ©2000-2025, vBulletin Solutions Inc.