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10-27-2008, 08:23 PM
#3
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i ready have a stage 2 but i been running nitrous on my car lot n i just wanted to start building the motor but i wanted to know if i need tuning or will the car drive the same with out a problem with the stage two n the pistons n rods
10-27-2008, 08:31 PM
#6
your assuming he's going with stock 9.5:1 compression
what compression ratio are you going with with the new pistons? if its higher than stock, you DEFINITELY need a tune, and if its lower than stock (you probably want to go in this direction), then a tune would be ideal, but not needed
what compression ratio are you going with with the new pistons? if its higher than stock, you DEFINITELY need a tune, and if its lower than stock (you probably want to go in this direction), then a tune would be ideal, but not needed
10-28-2008, 10:37 AM
#9
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Changing pistons would not require a tune anymore then running a bigger or smaller pulley. As with any mod though, you will get more benefit if you tune.
If you were to go with higher compression pistons you could definately run into detonation problems and a tune would be a good idea. Typically you don't want to run higher compression unless you are staying with a bigger pulley.
your assuming he's going with stock 9.5:1 compression
what compression ratio are you going with with the new pistons? if its higher than stock, you DEFINITELY need a tune, and if its lower than stock (you probably want to go in this direction), then a tune would be ideal, but not needed
what compression ratio are you going with with the new pistons? if its higher than stock, you DEFINITELY need a tune, and if its lower than stock (you probably want to go in this direction), then a tune would be ideal, but not needed
Last edited by rnjmur; 10-28-2008 at 10:37 AM. Reason: Automerged Doublepost
10-28-2008, 05:59 PM
#10
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I don't think higher compression is nessesarily a bad idea. Let's say I want to get the max out of my M62 and then run nitrous for the track. I want to run water/meth, and after 20-something degrees or timing advance, more timing doesn't yield alot more power does it? So why not throw in some 10.5:1 or even 11:1 cr pistons? Sounds like an idea to me...
10-28-2008, 07:37 PM
#11
Changing pistons would not require a tune anymore then running a bigger or smaller pulley. As with any mod though, you will get more benefit if you tune.
If you were to go with higher compression pistons you could definately run into detonation problems and a tune would be a good idea. Typically you don't want to run higher compression unless you are staying with a bigger pulley.
If you were to go with higher compression pistons you could definately run into detonation problems and a tune would be a good idea. Typically you don't want to run higher compression unless you are staying with a bigger pulley.
and im well aware of the relation of boost pressure to CR, thank you
I don't think higher compression is nessesarily a bad idea. Let's say I want to get the max out of my M62 and then run nitrous for the track. I want to run water/meth, and after 20-something degrees or timing advance, more timing doesn't yield alot more power does it? So why not throw in some 10.5:1 or even 11:1 cr pistons? Sounds like an idea to me...
10-28-2008, 10:55 PM
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on the opposite end of things.. what if the compression was droped to lets say 9:1 or even 8.5:1 would this be worth it if a 2.5 pully was added? lower the compression but raise the boost... would this be safe or even worth it?
10-28-2008, 11:55 PM
#13
Area likes to point out that with our blowers, its easier to make power by adding ignition timing rather than adding more psi
10-29-2008, 12:19 AM
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10-29-2008, 07:49 AM
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you can do this...what you are saying would be the normal procedure for our cars, but the M62 is way out of its efficiency range with a 2.5" pulley, so you will likely yield less HP going this route. Basically, while the CR you are saying can take the added airflow much better than stock, there will still be way too much heat in the intake charge, which will lead to detonation.
Area likes to point out that with our blowers, its easier to make power by adding ignition timing rather than adding more psi
Area likes to point out that with our blowers, its easier to make power by adding ignition timing rather than adding more psi
just trying to learn some new things
10-29-2008, 07:57 AM
#16
^^ while those all combat the heat, they dont stop it. say a stock setup removes 30% of the heat, and the above setup removes 70% of the heat... there will still be added heat to the system, and the faster the blower spins, the more heat is made, at an exponential rate
Lets just say most of the people who blew their stock motors on the m62 had 2.5" pulleys
Lets just say most of the people who blew their stock motors on the m62 had 2.5" pulleys
10-29-2008, 08:02 AM
#17
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You only need to tune if you change the physics/chemistry of the engine.
Example:
Anything that drops temperatures like meth or a heat exchanger. If you change piston size/compression, it changes the chemistry of the Air to Fuel (AFR).
10-29-2008, 08:33 AM
#18
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^^ while those all combat the heat, they dont stop it. say a stock setup removes 30% of the heat, and the above setup removes 70% of the heat... there will still be added heat to the system, and the faster the blower spins, the more heat is made, at an exponential rate
Lets just say most of the people who blew their stock motors on the m62 had 2.5" pulleys
Lets just say most of the people who blew their stock motors on the m62 had 2.5" pulleys
10-29-2008, 10:14 AM
#19
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I was also pretty much agreeing with what you said just throwing a bit of explaination in there for the OP who obviously DOESN'T know.
10-29-2008, 04:21 PM
#20
this is correct. I PERSONALLY would not reccomend a lower CR unless going with the TVS, or a turbo swap
10-29-2008, 09:19 PM
#21
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thanks man... sounds like if i were to lower the compression... it would be a fortune...by the time i got pistons, rings, connecting rods, and port the head... i would have to then by a harrop and get it tuned... this thing would have so much money dumped into it... but man would it be worth it in the end 