My ongoing 8.1 adventures...
09-02-2014, 10:18 PM
#92
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Good thinking, the 90mm snout on the Cool Gap is good for another 12-15hp.
Couple things to point out on the 3 bolt to 4 bolt adapter plate. There's no crank vent in the LS2 4 bolt style throttle bodies, so you'll want to install an oil breather. In drive by wire applications, you'll want to pick up a LS1 to LS2 harness kit.
When its all put together, it'll look something like the internally modified stock manifold on the Suburban. We used a $20 stainless mesh push in oil breather from the local ORiley's and shoved it into a hole drilled in the stock oil cap.
Unfortunately, the 90mm snout on the modded manifold doesn't really show much of an effect with the ported iron heads, roughly 3-5hp past the 20hp we picked up from the modded manifold in the first place. By the time that the extra CFM the 90mm provides becomes really useable (4000 - 6000 RPM) - the stock heads are already done flowing air and are on the decline.
Couple things to point out on the 3 bolt to 4 bolt adapter plate. There's no crank vent in the LS2 4 bolt style throttle bodies, so you'll want to install an oil breather. In drive by wire applications, you'll want to pick up a LS1 to LS2 harness kit.
When its all put together, it'll look something like the internally modified stock manifold on the Suburban. We used a $20 stainless mesh push in oil breather from the local ORiley's and shoved it into a hole drilled in the stock oil cap.
Unfortunately, the 90mm snout on the modded manifold doesn't really show much of an effect with the ported iron heads, roughly 3-5hp past the 20hp we picked up from the modded manifold in the first place. By the time that the extra CFM the 90mm provides becomes really useable (4000 - 6000 RPM) - the stock heads are already done flowing air and are on the decline.
Last edited by Raylar Engineering; 09-02-2014 at 10:42 PM.
09-03-2014, 05:28 AM
#93
I'll take pics of mine when the sun comes out. All my trucks are DBC
And I am turbo charging this engine. so the Bigger TB will help
And these heads are CNC ported 1.88 exhaust valves 11/32nd stems
This engine with a rear mount turbo made this
Well as soon as i find the dyno sheet here is pics of the head
This is shorty header and stock intake and tb dyno at the wheels
And I am turbo charging this engine. so the Bigger TB will help
And these heads are CNC ported 1.88 exhaust valves 11/32nd stems
This engine with a rear mount turbo made this
Well as soon as i find the dyno sheet here is pics of the head
This is shorty header and stock intake and tb dyno at the wheels
09-03-2014, 07:17 AM
#95
And my oil breather I had more ring gap put into it so when i boosted it my rings wouldnt be butting. so i run this homemade breather
Unfortunately when i switched to your intake and it uses the stock fuel rails it covers one of the fittings so i got to make some new ones to fix the issue so i can breathe both valve covers again.
Stock tb wild mild port work
Unfortunately when i switched to your intake and it uses the stock fuel rails it covers one of the fittings so i got to make some new ones to fix the issue so i can breathe both valve covers again.
Stock tb wild mild port work
09-03-2014, 08:16 PM
#96
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All good stuff, especially the turbo dyno.
This rear wheel dyno information for the ported heads we've seen before as a 496 MAG (base) crank output with stock cam / intake and ported heads. It would be exceptionally high for an NA 8.1L with iron heads to the ground, are you sure this isn't adjusted to crank output?
The reason I say this is that our 540cid puts out 335hp/475ft-lbs rear wheel with ported stock heads, intake manifold and 203 cam. 425hp/500ft-lbs is a wide jump over stock 250hp/360ft-lbs that everyone sees from the stock engine at the tires. Assuming those are actually crank numbers, rear wheel would be closer to 320hp/380ft-lbs, which is more in line with what we've seen from about every 8.1L we've seen with ported iron heads. 70rwhp is a pretty generous gain for ported heads.
This rear wheel dyno information for the ported heads we've seen before as a 496 MAG (base) crank output with stock cam / intake and ported heads. It would be exceptionally high for an NA 8.1L with iron heads to the ground, are you sure this isn't adjusted to crank output?
The reason I say this is that our 540cid puts out 335hp/475ft-lbs rear wheel with ported stock heads, intake manifold and 203 cam. 425hp/500ft-lbs is a wide jump over stock 250hp/360ft-lbs that everyone sees from the stock engine at the tires. Assuming those are actually crank numbers, rear wheel would be closer to 320hp/380ft-lbs, which is more in line with what we've seen from about every 8.1L we've seen with ported iron heads. 70rwhp is a pretty generous gain for ported heads.
Last edited by Raylar Engineering; 09-03-2014 at 08:28 PM.
09-06-2014, 03:48 PM
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09-07-2014, 12:41 PM
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