timing / compression...

[nightspeed87]

Going to be running 2g pistons in my car and have already had a few different convos with people using them, I hear for 1gs you cant even run over 11lbs of boost without getting knock because of 1g timing advance... I eventually want to get it chipped ( since the 1g timing advance is too aggressive for that 8:5 compression ratio ) but was wondering what gives off more power.... More compression less timing or more timing less compression? Im thinking compression and Im thinking compression is safer, but Im just curious to why 2gs are rated with more power but have less timing, smaller intake systems, smaller turbos etc.... I was thinking the compression gave that bump up of power? Any light on my questions would be nice.. And would also like to get a bunch of different opinions or reviews from ppl who actually have used them and different experiences

 

[Kevin Jewer]

2Gs ran more boost, that's where the extra power came from. With turbo charged cars liek ours compression plays a pretty small role in power production by itself.

 

[92DSMErdrick]

Are you running an AFC? You should be able to tune the car so you don't knock. I'm running 2g Pistons and I only knock at the top end b/c my turbo can't flow and I become rich. Get some datalogging tools and some means of tuning the car.

 

[nightspeed87]

I dont have a logger, keydriver chip or afc yet thats why im worried...
And I didnt know 2gs ran more boost stock than 1gs did so that explains it... Thanks for that piece of info, I always thought it had to do with the bump up of compression...
But still with the 2g compression by the time I get to tune out the knock and have custom
timing tables on the chip reasonably every time I raise the boost I still should be gaining more hp per boost raise than I wouldve on the stock 1g pistons, correct? Otherwise what would be the point of running 2g pistons and why would it be so popular?
I still would like more intimate information on 2g pistons on the 1g car, and some more experiences with that in mind... I am still on the stock turbo ( ported ) by the way so im sure 11- 12 lbs on a 14b isnt as much as that same boost on a 16g or greater so maybe there still is a chance I could run 12 to 13 lbs of boost knock free on my 14b for know? since most the guys ive talked to who say they cant run more than 11lbs without knock on 2g pistons have 16gs.
Another reason of concern is because im breaking in the engine soon and dont want it to be knocking also on breaking in .

 

[Kevin Jewer]

The airflow difference between a 14b and 16g at 11 or 12 psi is going to be negligible, and only because of the change in VE due to using different turbine housings. Outlet temps should be very similar at such low boost. You only start to see appreciable differences when one of the two compressor in question approaches it's limits.

 

[nightspeed87]

I see... 95GSXracer, I sent you another pm in the private messages...

So at a equal amount of boost, what do you benefit more from, timing or compression?
( as in more of one and less of the other )
And any one else with 2g piston experiences feel free to jump in... Any advice/ tips on my situation would help; thanks....

 

[Kevin Jewer]

I would rather sacrifice compression, but I don't have anything to backup my feeling on this subject this time, so I don't talk much about it. It's just an opinion I have based on the sum of my experiences with different ratios. I honestly don't feel compression has much of an effect. I just go with the standard 9:1 when I build motors for my cars.

 

[nightspeed87]

thats interesting ive heard overs claim power gains over compression?
And how much boost does stock 2gs run? Maybe only 1lbs more or so id think.

 

[Kevin Jewer]

3-4 psi.