GA High Comp Build
- Thread starter CoV
- Start date
A little work today setting piston ring gaps and working out an accurate c.r. Popped a piston and rings 15mm down into the bore, calculated the volume if it was flat top piston. Greased the lip, popped on the Perspex and pumped in the fluid which indicates a piston dome of 5.7cc. This works out to a 12:1 ratio which I was glad to see as I've not seen anything official of what these pistons provide. Just some foreign dodgy tuner stating it.
Received new lambda sensor and hrc fuel pump today also. Injectors came back from cleaning, both the USDM pink GA and sr20 injectors were pretty good flowing before cleaning, but nice to know they're squeaky clean and flow well now. Peace of mind .
Received new lambda sensor and hrc fuel pump today also. Injectors came back from cleaning, both the USDM pink GA and sr20 injectors were pretty good flowing before cleaning, but nice to know they're squeaky clean and flow well now. Peace of mind .
Mapping was on for 18th July, things didn't go to plan with obtaining parts so mapping is on for 15th August. As soon as my enamel paint arrives and I've sprayed the block I will be assembling it. Literally for a garage full of parts I'm itching to add to the block. Got my graphogen running in assembly lube, flange sealant. As soon as the paint lands it's game on.
I can't help but wonder about power output. 100bhp+ per litre is quite achievable on the sr20 with similar compression etc so fingers are crossed.
I can't help but wonder about power output. 100bhp+ per litre is quite achievable on the sr20 with similar compression etc so fingers are crossed.
Did you ever make those graphs Paul?
Out of interest i've just been comparing the headflow of the GA vs the SR20DE highport head. The GA head isnt as bad as i had first thought, particulary the intake side.
Stock DE Highport Head flows:
INTAKE: 208 cfm @ 28" Mercury OR 124 cfm @ 10" water
EXHAUST: 148 cfm @ 28" Mercury OR 88cfm @ 10" water
@ 0.400" LIFT
Stock GA Head flows:
INTAKE: 167 cfm tested @ 28" Mercury OR 100 cfm @ 10" Water
EXHAUST:116 cfm tested @ 28 Mercury OR of 70 cfm @ 10" water
Measured @ 0.350" LIFT
Paul's GA head flows:
INTAKE: 177cfm @ 28" Mercury OR 108 cfm @ 10" water
EXHAUST: 128cfm@ 28" Mercury OR 77cfm @ 10" water
Measured @ 0.350" Lift
.......
Citroen Saxo 1.6 VTS (16v) 120bhp
INTAKE: 173 cfm @ 28" Mercury OR 104 cfm @ 10" water
EXHAUST: 140cfm @ 28" Mercury OR 84 cfm @ 10" water
^ Regarding power potential of your motor Paul, i believe the 1.6 VTS engines are attaining 150bhp fairly easily with intake/exhaust and cams, and the headflow is similar, the GA is down a bit on the exhaust still, but the extra compression will help compensate for that.
Awesome!
Yeah I forgot to post the graph lol
Intake STD: @ 8.89mm/0.350" = 99.4cfm
Intake P&P: ". = 105.8cfm
Exhaust STD: @ 8.89mm/0.350" = 70.7cfm
Exhaust P&P: ". = 77.6 cfm
The figures climb only a tiny bit more after this lift but that's irrelevant as the regrinds can only supply around 9mm lift, John Middleton explained that to gain duration on regrinds the lift has to suffer.
Standard lift is a shocking 7.5mm, regrinds give 9mm
Yeah I forgot to post the graph lol
Intake STD: @ 8.89mm/0.350" = 99.4cfm
Intake P&P: ". = 105.8cfm
Exhaust STD: @ 8.89mm/0.350" = 70.7cfm
Exhaust P&P: ". = 77.6 cfm
The figures climb only a tiny bit more after this lift but that's irrelevant as the regrinds can only supply around 9mm lift, John Middleton explained that to gain duration on regrinds the lift has to suffer.
Standard lift is a shocking 7.5mm, regrinds give 9mm
First mapping session was a 9hr flop, too many wiring changes made by nissan between phases, cunts. Going back in 2 weeks so hopefully have it fully mapped and with figures to show.
Even with dizzy retarded it hesitates and pinks reasonably bad until 3k then its epic. Just hope at 13:1 it can be tuned atall and a big bonus if decent power can be made. It does spin up 205 rubber at half throttle though so it's looking hopeful. 400 miles on the engine so far. Warms up quite quickly and the bay temperatures are a bit mad but may end up wrapping the manifodl once i know its all running right. Once running with decent speed the water temps stay at 85 (thermostat setting) but in traffic the fans come on very often so may upgrade to an ally rad at later stage. All in all its going alright so far, few issues need ironing out but it works and started first time.
Had to put a bung in the exhaust, as this engine has made the exhaust i had on the Si atleast twice as loud, strange, must be pumping hard.
Even with dizzy retarded it hesitates and pinks reasonably bad until 3k then its epic. Just hope at 13:1 it can be tuned atall and a big bonus if decent power can be made. It does spin up 205 rubber at half throttle though so it's looking hopeful. 400 miles on the engine so far. Warms up quite quickly and the bay temperatures are a bit mad but may end up wrapping the manifodl once i know its all running right. Once running with decent speed the water temps stay at 85 (thermostat setting) but in traffic the fans come on very often so may upgrade to an ally rad at later stage. All in all its going alright so far, few issues need ironing out but it works and started first time.
Had to put a bung in the exhaust, as this engine has made the exhaust i had on the Si atleast twice as loud, strange, must be pumping hard.
Still able to bring it to JAE?
Nice one, massive figures for a na ga
Torque line looks a lot healthier than a sr16 too
Torque line looks a lot healthier than a sr16 too