WTF
09-30-2008, 12:25 AM
#41
Join Date: May 2007
Location:
Posts: 26
First of all, I'm not trying to prove anyone wrong, but hoping to clarify what might have been misunderstood.
magden_auto, you're spot on. that's both a perfect description and understandable. good work!
06Saleen3V, higher octane fuel, as mentioned in the wikipedia article, might raise combustion temps. What magden_auto was refering to was that adding spark with the same octane fuel (which you can only do if your octane is high enough to add spark!) reduces the exhaust gas temperature because it harnesses more useful work from the explosion instead of it escaping out the exhaust as heat energy. Raising pressures due to increased spark will lower temperatures with the same load and a/f because there is less heat energy from the explosion in the exhaust gas. If pressures are raised because boost is increased, then yes, temperatures will increase as well.
It's also worthwhile to mention that octane boost raises your octane very marginally. usually it lists in the fine print that it raises your octane under 0.5 octane, and the stuff is really expensive! it's also been credited with fouling spark plugs, but i don't have data to prove that.
also, a moot point, but "I dont believe it matters too much if the timing is too retarded or advanced" as far as discussions on the forums go, a good rule of thumb is that too much spark advance causes spark knock (aside from the tons of other things like cylinder heat, load, a/f, compression, etc) and you should retard timing if your vehicle is knocking.
i think you guys are both right, but just some points needed a little clarifying.
magden_auto, you're spot on. that's both a perfect description and understandable. good work!
06Saleen3V, higher octane fuel, as mentioned in the wikipedia article, might raise combustion temps. What magden_auto was refering to was that adding spark with the same octane fuel (which you can only do if your octane is high enough to add spark!) reduces the exhaust gas temperature because it harnesses more useful work from the explosion instead of it escaping out the exhaust as heat energy. Raising pressures due to increased spark will lower temperatures with the same load and a/f because there is less heat energy from the explosion in the exhaust gas. If pressures are raised because boost is increased, then yes, temperatures will increase as well.
It's also worthwhile to mention that octane boost raises your octane very marginally. usually it lists in the fine print that it raises your octane under 0.5 octane, and the stuff is really expensive! it's also been credited with fouling spark plugs, but i don't have data to prove that.
also, a moot point, but "I dont believe it matters too much if the timing is too retarded or advanced" as far as discussions on the forums go, a good rule of thumb is that too much spark advance causes spark knock (aside from the tons of other things like cylinder heat, load, a/f, compression, etc) and you should retard timing if your vehicle is knocking.
i think you guys are both right, but just some points needed a little clarifying.
09-30-2008, 01:37 PM
#42
6th Gear Member
Join Date: Apr 2007
Location:
Posts: 6,414
First of all, I'm not trying to prove anyone wrong, but hoping to clarify what might have been misunderstood.
magden_auto, you're spot on. that's both a perfect description and understandable. good work!
06Saleen3V, higher octane fuel, as mentioned in the wikipedia article, might raise combustion temps. What magden_auto was refering to was that adding spark with the same octane fuel (which you can only do if your octane is high enough to add spark!) reduces the exhaust gas temperature because it harnesses more useful work from the explosion instead of it escaping out the exhaust as heat energy. Raising pressures due to increased spark will lower temperatures with the same load and a/f because there is less heat energy from the explosion in the exhaust gas. If pressures are raised because boost is increased, then yes, temperatures will increase as well.
It's also worthwhile to mention that octane boost raises your octane very marginally. usually it lists in the fine print that it raises your octane under 0.5 octane, and the stuff is really expensive! it's also been credited with fouling spark plugs, but i don't have data to prove that.
also, a moot point, but "I dont believe it matters too much if the timing is too retarded or advanced" as far as discussions on the forums go, a good rule of thumb is that too much spark advance causes spark knock (aside from the tons of other things like cylinder heat, load, a/f, compression, etc) and you should retard timing if your vehicle is knocking.
i think you guys are both right, but just some points needed a little clarifying.
magden_auto, you're spot on. that's both a perfect description and understandable. good work!
06Saleen3V, higher octane fuel, as mentioned in the wikipedia article, might raise combustion temps. What magden_auto was refering to was that adding spark with the same octane fuel (which you can only do if your octane is high enough to add spark!) reduces the exhaust gas temperature because it harnesses more useful work from the explosion instead of it escaping out the exhaust as heat energy. Raising pressures due to increased spark will lower temperatures with the same load and a/f because there is less heat energy from the explosion in the exhaust gas. If pressures are raised because boost is increased, then yes, temperatures will increase as well.
It's also worthwhile to mention that octane boost raises your octane very marginally. usually it lists in the fine print that it raises your octane under 0.5 octane, and the stuff is really expensive! it's also been credited with fouling spark plugs, but i don't have data to prove that.
also, a moot point, but "I dont believe it matters too much if the timing is too retarded or advanced" as far as discussions on the forums go, a good rule of thumb is that too much spark advance causes spark knock (aside from the tons of other things like cylinder heat, load, a/f, compression, etc) and you should retard timing if your vehicle is knocking.
i think you guys are both right, but just some points needed a little clarifying.
09-30-2008, 05:31 PM
#43
1st Gear Member
Thread Starter
Join Date: Apr 2008
Location:
Posts: 66
Okay went to a different tuner and I can totally feel the difference. H.P numbers aren't that great but he was able to adj. fuel curve to raise the torque and rid the "rattle" under W.O.T.
We kept the tune from the 5th dyno run. Torque went from 334.93 to 362.90 with just fuel
and timing adjustment. He set the timing at 16-17. He only ran the car up to 5500RPM and max H.P was 296.81. If he would of pushed it to 65000, we probably get a little over 300hp.
Overall I'm OK with this considering that it has the stock intercooler(although with the gaps sealed) and the Series I S.C. Now as soon as I get 50 post I will post a want ad in our classified section looking for a Series IV S.C even if it just the head unit without the manifold.
It should fit, right?
I'll post dyno sheet later.
We kept the tune from the 5th dyno run. Torque went from 334.93 to 362.90 with just fuel
and timing adjustment. He set the timing at 16-17. He only ran the car up to 5500RPM and max H.P was 296.81. If he would of pushed it to 65000, we probably get a little over 300hp.
Overall I'm OK with this considering that it has the stock intercooler(although with the gaps sealed) and the Series I S.C. Now as soon as I get 50 post I will post a want ad in our classified section looking for a Series IV S.C even if it just the head unit without the manifold.
It should fit, right?
I'll post dyno sheet later.
haha....seriously, though im glad shes running more healthy
09-30-2008, 07:06 PM
#45
1st Gear Member
Thread Starter
Join Date: Apr 2008
Location:
Posts: 66
Yeah its cool if he didn't want to push the car. I told him I'd be back as soon as I upgrade to a series IV S.C or a Kenne bell.
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