408 little low on power
03-28-2011, 01:08 PM
#21
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[quote=jimbob;14702321]For E85, the numbers thrown around is generaly 3% more power. From what I'v seen at 12-12.5 compression look for about 15 more, maybe 20 rwhp (if your lucky) from the ethanol use. If you bumped comp up to 13-14 to 1 comp you can get more out of the engine. Really, E85 is not going to make much difference for timing requirments with our good heads, you'll probably still find low 20's work for max power and 2 or 3 degrees more timing added works for max torque. I'm finally swithching, we have a pump with 25 freeway miles now. If racing with it buy a cheap ethanal weigh set, just to make sure you have the same amount everytime you go to the track. On our more powerful 383 18* engine we're at 14.4 to 1. We will mix 109 with 90% ethanol. We will be ordering E100 and mixing our own. We could go 100 straight but you can never guarantee it's going to fire when it gets cold. Your in that compression range that E85 starts to really shine. There is some real good E85 info over at Corvette forums C6 section...
probly won't go that far..this is a street/strip car,figured 12.5-1 was to the edge of running race fuel..with 12.5-1 do you think afr 225 heads will flow enough or needs to be cut and opened up with what cam I have.
probly won't go that far..this is a street/strip car,figured 12.5-1 was to the edge of running race fuel..with 12.5-1 do you think afr 225 heads will flow enough or needs to be cut and opened up with what cam I have.
03-28-2011, 04:40 PM
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[QUOTE=69ls6;14702418] Yep, 12.5 is on the ragged edge for 92 octane depending on your actual DCR, cooling, engine VE, DA ect. I actually have 12.5 to 1 on my 401 Cubed LT1 "old school" But it has reverse cooling and seems to work ok. Timing down low blows though! Most Ls1 up here do OK at 12.0 comp with E10 92 octane. We also don't get past 90* in the summer so, this works out. If I was in the heat and had really good flowing heads, I might look for 12 to 1 SCR and 8.7 DCR (max), if using pump fuel. You can still get good power at 12.0 comp on E85.
You could also add Meth injection if your car doesn't like summer months (on premium pump gas).....E85 would fix any problem with octane at your compression...
AFR 225's work really well on 40X engines. I like there bigger heads on 42X-45X. The extra flow of the bigger heads and cubes really should require a great SP manifold to get every last ounce of power. I know my heads will be choked with a FAST and that's why I ordered my porting with smaller intake CC. Yeah, I give up 15-20 cfm @ .7 lift. But I'm not going that high lift anyway + Ported LS7 FAST only flows like 310 CFM MAX. You'll be fine with the 225's. With E85 on board you should easily go over 550. That's just a number anyway, but as long as you dyno at the same place you'll get a good handle on how much you gain. That cam you have will like the extra comp and should really show big gains in the TQ area.
One more thing. Advance your cam to 4 degrees total with that cam (108 ICl). That late abdc of that cam does not go well with stock or Fast intake. It may not show up as a double tq bump at the dyno but it will drop your low to mid range tq. That cam on a 408 has more than enough ability to go well past 7200rpm (most hyd lifters and springs don't like it much past this rpm anyway) so why not put your useable range down to below 7200....A ported FAST will generally peak at 6400-6500 on a 408 cube engine.
For E85, the numbers thrown around is generaly 3% more power. From what I'v seen at 12-12.5 compression look for about 15 more, maybe 20 rwhp (if your lucky) from the ethanol use. If you bumped comp up to 13-14 to 1 comp you can get more out of the engine. Really, E85 is not going to make much difference for timing requirments with our good heads, you'll probably still find low 20's work for max power and 2 or 3 degrees more timing added works for max torque. I'm finally swithching, we have a pump with 25 freeway miles now. If racing with it buy a cheap ethanal weigh set, just to make sure you have the same amount everytime you go to the track. On our more powerful 383 18* engine we're at 14.4 to 1. We will mix 109 with 90% ethanol. We will be ordering E100 and mixing our own. We could go 100 straight but you can never guarantee it's going to fire when it gets cold. Your in that compression range that E85 starts to really shine. There is some real good E85 info over at Corvette forums C6 section...
probly won't go that far..this is a street/strip car,figured 12.5-1 was to the edge of running race fuel..with 12.5-1 do you think afr 225 heads will flow enough or needs to be cut and opened up with what cam I have.
probly won't go that far..this is a street/strip car,figured 12.5-1 was to the edge of running race fuel..with 12.5-1 do you think afr 225 heads will flow enough or needs to be cut and opened up with what cam I have.
You could also add Meth injection if your car doesn't like summer months (on premium pump gas).....E85 would fix any problem with octane at your compression...
AFR 225's work really well on 40X engines. I like there bigger heads on 42X-45X. The extra flow of the bigger heads and cubes really should require a great SP manifold to get every last ounce of power. I know my heads will be choked with a FAST and that's why I ordered my porting with smaller intake CC. Yeah, I give up 15-20 cfm @ .7 lift. But I'm not going that high lift anyway + Ported LS7 FAST only flows like 310 CFM MAX. You'll be fine with the 225's. With E85 on board you should easily go over 550. That's just a number anyway, but as long as you dyno at the same place you'll get a good handle on how much you gain. That cam you have will like the extra comp and should really show big gains in the TQ area.
One more thing. Advance your cam to 4 degrees total with that cam (108 ICl). That late abdc of that cam does not go well with stock or Fast intake. It may not show up as a double tq bump at the dyno but it will drop your low to mid range tq. That cam on a 408 has more than enough ability to go well past 7200rpm (most hyd lifters and springs don't like it much past this rpm anyway) so why not put your useable range down to below 7200....A ported FAST will generally peak at 6400-6500 on a 408 cube engine.
Last edited by jimbob; 03-28-2011 at 05:05 PM.
03-28-2011, 05:36 PM
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[quote=jimbob;14703346] I thought there was a station that sold e85 locally,but theres not,so no e85.Is there anything to do beside just putting in e85 in tank..I've heard that it made more power and cooler.
Yep, 12.5 is on the ragged edge for 92 octane depending on your actual DCR, cooling, engine VE, DA ect. I actually have 12.5 to 1 on my 401 Cubed LT1 "old school" But it has reverse cooling and seems to work ok. Timing down low blows though! Most Ls1 up here do OK at 12.0 comp with E10 92 octane. We also don't get past 90* in the summer so, this works out. If I was in the heat and had really good flowing heads, I might look for 12 to 1 SCR and 8.7 DCR (max), if using pump fuel. You can still get good power at 12.0 comp on E85.
You could also add Meth injection if your car doesn't like summer months (on premium pump gas).....E85 would fix any problem with octane at your compression...
AFR 225's work really well on 40X engines. I like there bigger heads on 42X-45X. The extra flow of the bigger heads and cubes really should require a great SP manifold to get every last ounce of power. I know my heads will be choked with a FAST and that's why I ordered my porting with smaller intake CC. Yeah, I give up 15-20 cfm @ .7 lift. But I'm not going that high lift anyway + Ported LS7 FAST only flows like 310 CFM MAX. You'll be fine with the 225's. With E85 on board you should easily go over 550. That's just a number anyway, but as long as you dyno at the same place you'll get a good handle on how much you gain. That cam you have will like the extra comp and should really show big gains in the TQ area.
One more thing. Advance your cam to 4 degrees total with that cam (108 ICl). That late abdc of that cam does not go well with stock or Fast intake. It may not show up as a double tq bump at the dyno but it will drop your low to mid range tq. That cam on a 408 has more than enough ability to go well past 7200rpm (most hyd lifters and springs don't like it much past this rpm anyway) so why not put your useable range down to below 7200....A ported FAST will generally peak at 6400-6500 on a 408 cube engine.
You could also add Meth injection if your car doesn't like summer months (on premium pump gas).....E85 would fix any problem with octane at your compression...
AFR 225's work really well on 40X engines. I like there bigger heads on 42X-45X. The extra flow of the bigger heads and cubes really should require a great SP manifold to get every last ounce of power. I know my heads will be choked with a FAST and that's why I ordered my porting with smaller intake CC. Yeah, I give up 15-20 cfm @ .7 lift. But I'm not going that high lift anyway + Ported LS7 FAST only flows like 310 CFM MAX. You'll be fine with the 225's. With E85 on board you should easily go over 550. That's just a number anyway, but as long as you dyno at the same place you'll get a good handle on how much you gain. That cam you have will like the extra comp and should really show big gains in the TQ area.
One more thing. Advance your cam to 4 degrees total with that cam (108 ICl). That late abdc of that cam does not go well with stock or Fast intake. It may not show up as a double tq bump at the dyno but it will drop your low to mid range tq. That cam on a 408 has more than enough ability to go well past 7200rpm (most hyd lifters and springs don't like it much past this rpm anyway) so why not put your useable range down to below 7200....A ported FAST will generally peak at 6400-6500 on a 408 cube engine.
03-28-2011, 05:56 PM
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[QUOTE=69ls6;14703629]The biggest thing is to have enough pump and injectors. The "General" rule of thumb is about 30% more fuel needed. There is some metals that don't like ethanol, but you should be ok. Look at the thread going on in the fueling and injection section....I know brass doesn't like it but I have never actually seen any issues with it. Stainless is all good....
