2.5l - 10.25:1 compression - EVO IX motor pictures!
Jun 19, 2007, 03:07 PM
#50
Evolved Member
iTrader: (5)
Join Date: Aug 2005
Location: Florida
Posts: 1,878
Likes: 0
Received 0 Likes
on
0 Posts
ok, so theres not a 93 octane tune in mind then?
i guess my question was geared more towards the range of 93 octane....like for our car stock you can run 22 psi with out much trouble. i would think that if i took my car and swapped my stock compression pistons for 10.25 i would think it would knock too much at 22 psi so i would have to lower that to lets say 18 psi, but i would get more power at less boost on 93 octane.
sounds like a sick setup though
i guess my question was geared more towards the range of 93 octane....like for our car stock you can run 22 psi with out much trouble. i would think that if i took my car and swapped my stock compression pistons for 10.25 i would think it would knock too much at 22 psi so i would have to lower that to lets say 18 psi, but i would get more power at less boost on 93 octane.
sounds like a sick setup though
I thought it was weird for Mike was saying they run 22 low boost, and 28 high boost on this setup; because that strangly mimics exactly how this turbo should be boosted on a stock comp. ratio 4g63 - that is 22 on pump and 28 psi on race gas...
I can tell you right now that there is no way this motor can boost 22 psi on pump gas, with any reasonable amount of timing; without knocking.
Jun 20, 2007, 12:14 AM
#58
Yes you are correct.
I thought it was weird for Mike was saying they run 22 low boost, and 28 high boost on this setup; because that strangly mimics exactly how this turbo should be boosted on a stock comp. ratio 4g63 - that is 22 on pump and 28 psi on race gas...
I can tell you right now that there is no way this motor can boost 22 psi on pump gas, with any reasonable amount of timing; without knocking.
I thought it was weird for Mike was saying they run 22 low boost, and 28 high boost on this setup; because that strangly mimics exactly how this turbo should be boosted on a stock comp. ratio 4g63 - that is 22 on pump and 28 psi on race gas...
I can tell you right now that there is no way this motor can boost 22 psi on pump gas, with any reasonable amount of timing; without knocking.
BTW KO, this wasnt meant to be anything other than instructional...its not an attack just a radical way of clarifying some points. Subaru WRC Rally cars with 92mm bores run 3 Bar through a 30mm and a 10:1 motor or HIGHER depending on altitude on control fuel. Look up the octane rating of FIA control gasoline and you will have a stroke. Like Ted said to Bill "strange things are afoot at the Circle K".
Now from the standpoint of Mike running a similar motor on the street on pump at 22, it depends on what you mean by "reasonable" timing. Considering the stock timing map has about -3* of timing there at peak torque, more than that could be considered reasonable. Is it the 6-7 that a 2.0/8.8 motor could run, no but its still more than the stock 2.0/8.8 motors timing would have. I suppose in that situation I would tend to agree with you more than I would disagree. That rally motor on pump gas would be another matter though. Sorry if it came across wrong or beligerant at first.
JB
Last edited by JohnBradley; Jun 20, 2007 at 12:41 AM.
Jun 20, 2007, 09:33 AM
#59
Evolved Member
iTrader: (1)
Join Date: Mar 2005
Location: Mesoamerica/ SF Bay Area
Posts: 7,905
Likes: 0
Received 5 Likes
on
5 Posts
We have been using the 4G64 block for years with a good bit of success, and will continue to do so. It worked well in the 2.1l we ran at 100 acre wood rally, and I am sure will be fine in this configuration as well. Taller deck height, bigger bore, seems logical to me as well 
Next month I am building one for my daily driver, but with 106 mm billet crank - that should be interesting!
Mike Huml
SBR Inc.
Next month I am building one for my daily driver, but with 106 mm billet crank - that should be interesting!Mike Huml
SBR Inc.
Last edited by sparky; Jun 20, 2007 at 09:37 AM.
