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Thread: 1.6 vvl turbo comp ratio?

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Posts: 1-10 of 11
2011-05-11 15:13:17
#1
1.6 vvl turbo comp ratio?
ok need to know if this build is possible before i waste my time.

i want to aim for around 9-9.5:1 comp with 1 bar+ boost on an SR16VE engine. this engine is all about response, im not after gearbox breaking torque

my main question is the comp ratio. in that i have 8.5:1 pistons with a 16ve head AND crank, what will my comp be?
will be run on 99oct


Parts I have:
complete 16VE crank
JE 8.5:1 87mm pistons
GTI-R block (will be bored to 87mm)
16ve standard head
2.5" straight exhaust

parts i need:
custom eagle rods
gt2860rs
740cc inj
arp rod bolts
acl race bearings
vvl metal headgasket
2.5" downpipe
Link G4 storm ECU
oil cooler of some kind
some other bits, like intercooler etc

any help would be great guys

Steve
2011-05-11 16:13:15
#2
should be 9.3:1
2011-05-11 16:31:21
#3
Cheers pal, makes me feel a little more confident.

Will I gain much switching to 20ve cams?

Steve
2011-05-12 02:12:21
#4
Are these pistons 8.5:1 in an sr20? If so then the comp will drop significantly when using it with an sr16 crank. Something like 6.5:1. You could use STD sr20 pistons in an sr16 to reach about 8.5:1....
2011-05-12 02:13:51
#5
And keep the 16 cans unless you switch to 20vs
2011-05-12 16:41:50
#6
http://www.sr20-forum.com/turbo/39644-sr18vet-sr16-sr20-crank-based.html?highlight=sr18vet

the cr will be about 7

I think you should use 10:1 or 12:1 cr sr20vet CP Pistons and some thick gasket
I calculated the 3mm gasket with the 12:1 sr20vet pistons (sr20ve CP pistons). They will give about 11:1 cr in the sr16 engine and then you drop the cr with the headwork and the gasket
2011-05-12 16:48:46
#7
7 that's not good. Well I've bought the pistons already for a great price

What if I skim the head 1mm, obviously talking care with piston to valve contact?

Is there a thin headgasket available for the Sr That would survive high boost pressure?

Steve
2011-05-12 17:08:03
#8
You can skim the head, that might do the trick. But check the piston quench clearance and valve clearance. I forget that the SR16 pistons are built a bit differently than the 2.0. But keep the 1.6 cams. The 2.0 cams have faster opening rates to deal with higher piston speeds. The 1.6 has much lower piston speed, so I would keep the cams designed for that.
2011-05-12 18:20:59
#9
Originally Posted by steve55
ok need to know if this build is possible before i waste my time.

i want to aim for around 9-9.5:1 comp with 1 bar+ boost on an SR16VE engine. this engine is all about response, im not after gearbox breaking torque

my main question is the comp ratio. in that i have 8.5:1 pistons with a 16ve head AND crank, what will my comp be?
will be run on 99oct


Parts I have:
complete 16VE crank
JE 8.5:1 87mm pistons
GTI-R block (will be bored to 87mm)
16ve standard head
2.5" straight exhaust

parts i need:
custom eagle rods
gt2860rs
740cc inj
arp rod bolts
acl race bearings
vvl metal headgasket
2.5" downpipe
Link G4 storm ECU
oil cooler of some kind
some other bits, like intercooler etc

any help would be great guys

Steve


You could have just asked me for advice bud, as I would have been happy to help you.

GT28RS, yes, but go with the 0.64 AR housing to spool it quicker. This turbocharger is still able to pull over 350 HP.

740cc injectors are overkill, 444 cc S15 Silvia injectors @ 4 BAR base pressure will be enough for 400 HP.

ACL race bearings are not needed, OEM genuine Nissan bearings will be fine

Stock oil cooler is fine

Go with a 3" system if you can
2011-05-13 03:06:20
#10
the cp sr20ve 12.5:1 will be just over 10:1 in a sr16ve. running them seems like the best idea. maybe take a little out the cc to lower further
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