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Thread: SR20VE + N1 cams + CP 12.5:1 pistons

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Posts: 11-20 of 29
2010-11-27 18:46:38
#11
Originally Posted by Redline
quick question. Will the CP 12.5:1 Piston run fine with the Stock VE rod? or ill have to buy new one's... jw. Thanks.

Yes you can use stock rods.
Originally Posted by blo0d
When the cp pistons are installed, is the piston above the deck @ tdc?

I'm curious because it kinda gives the impression that flat top pistons in the 20ve will give a similar compression (of course reliefs have to be installed)... Am I wrong?

I guess my question is how does cp pistons achieve 12.5;1 with such deep reliefs and a flat top?

N1, 16ve, 12.5:1 cp's are all domed.
Originally Posted by javcrodgz
If I remember correctly, I heard that with the N1 pistons, unless you anticipate running 100+ Octane, you will have to down-tune the car. In which case you will not be making power to it's full potential. I think the 20V pistons are a better option if you plan on daily driving it on regular 93 or 91 octane.


You shouldn't have to run above 93 with N1 pistons. 16ve pistons I would be a little iffy about, but I have not tried them.
2010-11-27 23:39:47
#12
With my 12.5:1 cp's i've had to run a weak xylene mix with a bit of some nf race formula in my UK 99ron to get a decent ignition timing map. Thats with my top end timing into about the 30 odd mark iirc

although, tbh i don't know how much timing would be backed off to be ok on the 99ron, thats something i'm going to look at when i go back to my tuner.

What i can say is with 12.5:1, a 4cw de bottom end, a fidanza flywheel and greg v pulleys, the engine revs so quickly and responsively and the acceleration is awesome. I really think the high comp has made that, i can't remember feelin a stock compression motor with fly and pulleys feel that responsive and revvy lol
2010-11-28 06:46:11
#13
Your cp's are also quite a bit lighter than stock pistons.
2010-11-28 19:50:11
#14
Could you do something to make it run on pump gas ron 97/98 ?
2010-11-28 19:56:48
#15
12.5:1 will run fine on 93 oct and n1s. And you could probably even run 13:1 or so with the 184c

When I was running sr16 pistons on my motor it was fully tuned on 93oct. And then I mixed 110 and 93 to achieve a 100oct fuel and then retuned the motor. Set up being exactly the same and the motor gained 2whp and 2ftlbs after the tuning. So yes 12.5:1 cr is just fine on 93oct and you could probably run a litlle more compression from what I've found. But its a good safe point to settle with on pump gas.
2010-11-28 20:34:43
#16
ah, so going from that cory i probably won't lose much in hp or my timing map by ditching the xylene mix and just running UK 99ron - that will be A LOT less hassle then lol
2016-03-20 03:30:28
#17
Does 370cc injectors will be compliant with this 12.5 sr20ve pistons on 86.5 bore? Trying to avoid detonation as much as posible any tips?
2016-03-20 05:24:59
#18
Originally Posted by ztunedsr20
Does 370cc injectors will be compliant with this 12.5 sr20ve pistons on 86.5 bore? Trying to avoid detonation as much as posible any tips?


you will have no issues with 370's as long as your ecu can be adjusted to suit them, or you got an adjustable fuel pressure regulator. you shouldn't have any issues with knocking with your setup, as long as the timings right.
2016-04-15 14:15:00
#19
A Stock SR20VE with N1 CAMS, WAI, STOCK HEADER, STOCK PLENUM & TB and 3" CATBACK, will put something around 192 whp. (DYNOJET dyno)
The same setup with stock plenum and q45 TB, will add 6 whp, 198 whp.

We built a SR16VE stroked up to SR20VE.
Engine CR was indeed 12.5:1 (see this post).
We used N1 CAMS, Q45 throttle Body on the stock intake manifold (You need to cut it, modify it and weld a new flange) and a JDM exhaust header (unknown brand, it just has the JASMA certification logo)

Car made 206whp, but on the last 500 rpm (rev limiter at 8500 rpm) power goes quickly down. I pretty sure that the problem is indeed the intake manifold. (lots of power here)

We also built a stock internals SR20VE, with stock CR, using a Xcesive Plenum, Q45 throttle Body, Ported P12 Header, 3" catback and N1 cams, car made 214.5 whp with the rev limiter set to 9000 rpm. (See video here

So, CR add like 8-15 whp on the powerband (8 whp at the peak), Xcesive Plenum and P12 PORTED HEADER add amazing 15 whp peak power and 500 rpms more of powerband (still N1 CAMS).

My guess for that setup (SR20VE, 12.5:1 CR, XCESIVE PLENUM, SUPERTECH VALVE SPRINGS, Q45 TB, P12 PORTED HEADER, 3" CATBACK, 3.5" WAI with a good cold air box, Q45 MAF, NISTUNE/NISMOTRONIC/HALTECH (NO MAF for this one) and proper tuning) will be something between 220whp and 230 whp

Which will be nice!
2016-04-15 14:20:31
#20
Originally Posted by sss4me
Originally Posted by ztunedsr20
Does 370cc injectors will be compliant with this 12.5 sr20ve pistons on 86.5 bore? Trying to avoid detonation as much as posible any tips?


you will have no issues with 370's as long as your ecu can be adjusted to suit them, or you got an adjustable fuel pressure regulator. you shouldn't have any issues with knocking with your setup, as long as the timings right.


We have been using 333cc injectors up to 215 whp with no issues. However it should be wiser to use bigger injectors to avoid extreme duty cycles
Last edited by PuPPiesOnAciD on 2016-04-15 at 14-47-10.
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