No BS dyno test of Vararam CAI for G8

[Patrick G]

Patrick:What are the ballpark cam specs of the baby cam that you are thinking of going with. I know you are a cam & tuning expert, so I am very curious what kind of cam you are thinking of going with? (Especially the LSA).
*** Actually what specs on a cam would you use, if you were getting rid of DOD/AFM?
...

If I were to keep stock exhaust manifolds and cats but ditch AFM, then I'd probably run a 218/230 .595/.600" on a 115LSA. If I were to run headers, then it would probably be a 222/230 .597/.600" on a 114LSA. Like I said, baby cams with good lift (but not excessive lift), and easy to tune. These G8s are too nice to destroy with a big overlap cam. I'll save that for something much lighter, not my daily driver.

These 821 heads really respond to lift. The stock 6.0 AFM cam is only .472/.474" lift at the valves whereas the 6.2 GXP cam is .551" lift. If I could run a DOD cam with lobes that would give valve lift in the upper .500s, then I'd probably keep AFM engaged. But if the mid to upper .400s is all the lift I can run with DOD, then it's worth ditching AFM and going for a non-DOD .600" lift cam. I could look into getting 1.8 ratio rockers from an LS7 if I could run a DOD cam that could get me into the mid to upper .500s" on valve lift. A .472" valve lift with 1.7 rockers is a .277" cam lobe. .550" valve lift with 1.8 rockers is a .305" cam lobe. A .305" lobe is a baby lobe. Hmmm...maybe there's a project calling my name. I do like AFM and the fuel savings. Just gotta find out the real lift/spring pressure limit these DOD lifters can take.

[Patrick G]

You said you have an 87 octane tune. You used 93 to make sure there was no knock but did you use a 93 tune? If not then there is probably some more power left on the table. Sorry, didn't want to start another octane war but anyone feel free to correct me if I'm wrong.

My tune made the exact same power and torque on 87 octane as it did on 93 octane. Exactly the same. This leads me to believe that the tables are pretty well optimized for either octane. The motor only needs so much timing with its current set of mods. On 87 octane, there is an occasional amount of KR, but with 93 octane there is none.

My high octane spark tables and low octane spark tables are not very far apart so you're going to see some consistency regardless of the fuel you run. Any tuner that puts too much timing in the high octane spark table is going to make the engine knock enough to have the octane scaler drop you into the low octane spark table anyway. You want to make sure your low octane spark table gives you the best performance you can get because most of you are probably spending more time in that table than the high octane table. Log your runs and you'll know for sure.

With these recent tests with 93 octane, we disconnected the battery between runs and zeroed out the fuel trims so we were operating off the best timing tables and with an optimized A/F ratios. No BS.

[PostalCherokee]

k, sounds good to me. LOL. I'm a novice so this site is good for guys like me, learning lots.

[Mike P]

If I were to keep stock exhaust manifolds and cats but ditch AFM, then I'd probably run a 218/230 .595/.600" on a 115LSA. If I were to run headers, then it would probably be a 222/230 .597/.600" on a 114LSA. Like I said, baby cams with good lift (but not excessive lift), and easy to tune. These G8s are too nice to destroy with a big overlap cam. I'll save that for something much lighter, not my daily driver.

These 821 heads really respond to lift. The stock 6.0 AFM cam is only .472/.474" lift at the valves whereas the 6.2 GXP cam is .551" lift. If I could run a DOD cam with lobes that would give valve lift in the upper .500s, then I'd probably keep AFM engaged. But if the mid to upper .400s is all the lift I can run with DOD, then it's worth ditching AFM and going for a non-DOD .600" lift cam. I could look into getting 1.8 ratio rockers from an LS7 if I could run a DOD cam that could get me into the mid to upper .500s" on valve lift. A .472" valve lift with 1.7 rockers is a .277" cam lobe. .550" valve lift with 1.8 rockers is a .305" cam lobe. A .305" lobe is a baby lobe. Hmmm...maybe there's a project calling my name. I do like AFM and the fuel savings. Just gotta find out the real lift/spring pressure limit these DOD lifters can take.

Awesome! Thank you for answering my question. I defnitely want to make really good power, but the G8 GT is my daily driver so I'm really looking to have driveability 1st and power 2nd.

I'm looking for a car anywhere from 11.8x - 12.2 consistantly. I'll definitely have to fill out your cam profile document, but I totally appreciate your help!

My current cam specs now are:

228/236 .588/.578 " on a 112 + 4 LSA



Thinking of changing my cam, down the line......





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[R.Penguin]

Did you have a fan capable of producing the 50mph ( I think technically its 48) winds the vararam claims to produce more power at? I think thats a small catch...

One note.

Anyone that adds an aftermarket CAI (or any other) and does not finish it with Charlies "lower panel mods" is losing free HP!

Dropping the air filter under the engine compartment heat & opening up cooler air flow from below makes power. If you can isolate the AF from almost all heat sources

(you can just see the grey flexible foam....1.25" thick that is cut to block all underhood heat and fits snugly around the air intake tube.) Intake tube is New Era wrapped with 1/2" insulation then covered in flexible aluminum pipe. Perhaps too extreme for many.

When AAT is 90F or less the DH reports IAT at same as AAT. On really hot days (+100F) when underhood temp. is in 200+ range, IAT stays at 100F-106F unless in traffic.

IAT drops fast when back up to speed too.

[g8_795]

If I were to keep stock exhaust manifolds and cats but ditch AFM, then I'd probably run a 218/230 .595/.600" on a 115LSA. If I were to run headers, then it would probably be a 222/230 .597/.600" on a 114LSA. Like I said, baby cams with good lift (but not excessive lift), and easy to tune. These G8s are too nice to destroy with a big overlap cam. I'll save that for something much lighter, not my daily driver.

These 821 heads really respond to lift. The stock 6.0 AFM cam is only .472/.474" lift at the valves whereas the 6.2 GXP cam is .551" lift. If I could run a DOD cam with lobes that would give valve lift in the upper .500s, then I'd probably keep AFM engaged. But if the mid to upper .400s is all the lift I can run with DOD, then it's worth ditching AFM and going for a non-DOD .600" lift cam. I could look into getting 1.8 ratio rockers from an LS7 if I could run a DOD cam that could get me into the mid to upper .500s" on valve lift. A .472" valve lift with 1.7 rockers is a .277" cam lobe. .550" valve lift with 1.8 rockers is a .305" cam lobe. A .305" lobe is a baby lobe. Hmmm...maybe there's a project calling my name. I do like AFM and the fuel savings. Just gotta find out the real lift/spring pressure limit these DOD lifters can take.

I am running pretty close to that with my 230/236 590/600 114LSA. Little bit more duration, but it was easy to dial in even for a rookie like me.

[fiveoh]

If I were to keep stock exhaust manifolds and cats but ditch AFM, then I'd probably run a 218/230 .595/.600" on a 115LSA. If I were to run headers, then it would probably be a 222/230 .597/.600" on a 114LSA. Like I said, baby cams with good lift (but not excessive lift), and easy to tune. These G8s are too nice to destroy with a big overlap cam. I'll save that for something much lighter, not my daily driver.

These 821 heads really respond to lift. The stock 6.0 AFM cam is only .472/.474" lift at the valves whereas the 6.2 GXP cam is .551" lift. If I could run a DOD cam with lobes that would give valve lift in the upper .500s, then I'd probably keep AFM engaged. But if the mid to upper .400s is all the lift I can run with DOD, then it's worth ditching AFM and going for a non-DOD .600" lift cam. I could look into getting 1.8 ratio rockers from an LS7 if I could run a DOD cam that could get me into the mid to upper .500s" on valve lift. A .472" valve lift with 1.7 rockers is a .277" cam lobe. .550" valve lift with 1.8 rockers is a .305" cam lobe. A .305" lobe is a baby lobe. Hmmm...maybe there's a project calling my name. I do like AFM and the fuel savings. Just gotta find out the real lift/spring pressure limit these DOD lifters can take.

Hmm this sounds very similar to the livernois stage 1c cam which is listed as 218/229 .600/.600 117.5LSA.

Sounds like your goals for your car are very similar to mine.

[Mike P]

My current cam specs are

228/236 .588/.578 " on a 112 + 4 LSA

Thinking of changing my cam, down the line......

...

Looks like I could get a different cam and go a little more aggressive with the valve lift.

What is meant by a big overlap cam?



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[JimmyJazz]

I did a different version when I had a Roto fab. Jason at TSP did the dyno. Roughly, hp only,tq was about 5 more all the way up, stock 303, Rotofab 313, tune 330, all hood up..one last pull with hood down 320. I think the Vararam would do a little better with the hood down. All pulls were with the standard big fan in front of the car.

[dandragonrage]

What is meant by a big overlap cam?

Low LSA