Corleones new engine is running
08-22-2010, 03:35 PM
#272
Racer
Thread Starter
Yes, a long post from you, but don't stop. I appreciate your logic and openness about this. I have been running at target 0.78 so perhaps too rich.
Interesting considering your higher c/r too. I would think you would see some knock but I guess not? So you must have developed this idea over time and testing. I remember you doing many maps. Was your boost and/or ign too high in the past?
Interesting considering your higher c/r too. I would think you would see some knock but I guess not? So you must have developed this idea over time and testing. I remember you doing many maps. Was your boost and/or ign too high in the past?
E85 likes higher CR. I have had a lot of help from my engine friend who develops racing engines and dyno all day. They run 11:1 with 4 valve heads, again its all about hardware and timing. With a bit higher CR you have more basic power, better and earlier spoolup, cooler exhaust and so on. Isnt it a faster car we want with a good driveability...
I have started with gas and logged a lot of maps, checked and listened to knocks with Link knock amplifier, then when I had a proper gas ignition map i changed to E85 and rise ignition between 0-12 degrees depending on revs. From there it will always be some tuning anyway but you know whats pretty safe.
08-22-2010, 03:42 PM
#273
Racer
Thread Starter
I was reading elsewhere that the valve/spark plug configuration of the 16V head made it inherently less susceptible to detonation than the 8V heads, so (if true) that should allow for an increased CR all other things being equal.
This is why I was little surprised to see Sean had chosen a 8:1 CR for his 16V 3.0L build...
This is why I was little surprised to see Sean had chosen a 8:1 CR for his 16V 3.0L build...
Many of you still talk about knocks, you can all stop with that if we talk E85, thats not the problem. The big problem is paek cylinderpressure and that what kills the engine often before a knock. A knock with E85 will be just one big knock and then its over, yes you can have some single at very high revs but the difference to gas is that a gas knock is a lot small knocks as the gas/air burns in smaller parts, E85 when it knocks the hole mixture is knockin at one time, I promise you will notice...
08-22-2010, 03:45 PM
#274
Racer
Thread Starter
Neither do I but the explanation is that I had my 2.5 l before and already had the SFR st2 headers and a head with a lot of work.
A 16 V will produce about 80 more hp if the set up is simular to mine, about 750 hp. I really dont know if the block will handle that without major improvement.
A 16 V will produce about 80 more hp if the set up is simular to mine, about 750 hp. I really dont know if the block will handle that without major improvement.
08-22-2010, 10:14 PM
#277
Race Car
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what tires.. I couldn't get any type of street tire to stick through 3rd gear. Only top of 3rd held with street tires... 255\'s . Love the sound, but surprised its so quiet.
08-22-2010, 11:08 PM
#279
Drifting
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80% more thats pretty extream i would think perhaps 80% easier 
...your friends running 11:1 are they around 17 to 20 psi ?? I kind of feel that i have chickened out a bit as i have put a few more cc in the bowl of my 968 piston's as i was up near 11.3:1 i think i will still be above 10.5 so its still pretty manly ..
...your friends running 11:1 are they around 17 to 20 psi ?? I kind of feel that i have chickened out a bit as i have put a few more cc in the bowl of my 968 piston's as i was up near 11.3:1 i think i will still be above 10.5 so its still pretty manly ..
08-23-2010, 02:48 AM
#280
Racer
Thread Starter
80% more thats pretty extream i would think perhaps 80% easier ...your friends running 11:1 are they around 17 to 20 psi ?? I kind of feel that i have chickened out a bit as i have put a few more cc in the bowl of my 968 piston's as i was up near 11.3:1 i think i will still be above 10.5 so its still pretty manly ..
...your friends running 11:1 are they around 17 to 20 psi ?? I kind of feel that i have chickened out a bit as i have put a few more cc in the bowl of my 968 piston's as i was up near 11.3:1 i think i will still be above 10.5 so its still pretty manly ..
08-23-2010, 02:53 AM
#281
Racer
Thread Starter
I have one big silencer at the back and the cat is sittingjust before the rear axle. Separat 2" wg pipe all the way
08-23-2010, 05:14 AM
#282
Rennlist Member
Yes, you run much to rich.
E85 likes higher CR. I have had a lot of help from my engine friend who develops racing engines and dyno all day. They run 11:1 with 4 valve heads, again its all about hardware and timing. With a bit higher CR you have more basic power, better and earlier spoolup, cooler exhaust and so on. Isnt it a faster car we want with a good driveability...
I have started with gas and logged a lot of maps, checked and listened to knocks with Link knock amplifier, then when I had a proper gas ignition map i changed to E85 and rise ignition between 0-12 degrees depending on revs. From there it will always be some tuning anyway but you know whats pretty safe.
E85 likes higher CR. I have had a lot of help from my engine friend who develops racing engines and dyno all day. They run 11:1 with 4 valve heads, again its all about hardware and timing. With a bit higher CR you have more basic power, better and earlier spoolup, cooler exhaust and so on. Isnt it a faster car we want with a good driveability...
I have started with gas and logged a lot of maps, checked and listened to knocks with Link knock amplifier, then when I had a proper gas ignition map i changed to E85 and rise ignition between 0-12 degrees depending on revs. From there it will always be some tuning anyway but you know whats pretty safe.
I am running stock 8:0.1 pistons and stock head on this little 2.5L build and have been running to low 11's afr for some time. From memory the car does feel more alive when it's running leaner. On the track though I like to err on the side of caution for extended loads.
08-23-2010, 04:24 PM
#283
Racer
Thread Starter
What stoich / afr did you run with pump fuel and what was that octane?
I am running stock 8:0.1 pistons and stock head on this little 2.5L build and have been running to low 11's afr for some time. From memory the car does feel more alive when it's running leaner. On the track though I like to err on the side of caution for extended loads.
I am running stock 8:0.1 pistons and stock head on this little 2.5L build and have been running to low 11's afr for some time. From memory the car does feel more alive when it's running leaner. On the track though I like to err on the side of caution for extended loads.
08-23-2010, 06:19 PM
#284
Rennlist Member
Actually our 98 is probably the same as yours give or take. We're not on U.S. standards down here. You definitely run leaner than most here would suggest. Did you see much knock or pre ign on pump at those afrs?
08-24-2010, 02:05 PM
#285
Racer
Thread Starter
My MSD works very well and I think this is a good insurance to start with if you looking for high power.
Over and out.