From what I understand, stainless requires tig welding whereas aluminized doesn't. As such I have to use all ss or not and tig is more expensive. If the cones only come in ss, then I guess I'll have to go that route.Woolf has cones and transitions
http://catalog.woolfaircraft.com/ke...refer=http://www.woolfaircraft.com/index.html
Stainless doesn't have to be TIG welded. You can always just use stainless wire with a MIG if you want it to be clean, but you can still use the regular wire. You can weld mild and stainless together, etc.From what I understand, stainless requires tig welding whereas aluminized doesn't. As such I have to use all ss or not and tig is more expensive. If the cones only come in ss, then I guess I'll have to go that route.
Michael, Look at how "repeatable" back to back dyno runs are. It is not at all clear to me the dyno will actually be able to show a small delta results from anything but margin of error from the test itself. Does this make some sense?I'm aware that the idea of that evac chambered DP may not do anything significant for the setup relative to a straight up 2.5" exhaust, but curiosity beckons and someone has to spend some money (I'd dyno both) to see what gain, if any, there would be.
The general theory is that it'll aid in turbo spool-up and also lower EGTs.
+1 The guy who built my motor in the Impala worked for JBA (makes headers among other things) and they tested out "dimples" on headers. He said as long as they were minor, they didn't make a difference in power. The exhause gas would slow down at the "dimple" and as soon as it passed it, the gas sped up which increased scavenging.Hi, Michael.
I think the most conservative approach is to mark the areas of the pipe that are too close to the firewall and, after removing the pipe, flatten it for more clearance by tapping with a nice heavy hammer.
I don't think you will reduce flow enough to matter and you'll keep the pipe that is working for you. Best of all, it's free!
John, On that dyno when I was stock, there was less than a 1 hp difference between the runs. I'll have IAT & EGT gauges installed before putting this on a dyno. Doing 3 runs each with this DP, a 2.5" and possibly a final expansion chambered one with all of that data would still be significant. We've had 3 dyno days over a year and a half almost and our numbers haven't really changed so I think we'll be good.Michael, Look at how "repeatable" back to back dyno runs are. It is not at all clear to me the dyno will actually be able to show a small delta results from anything but margin of error from the test itself. Does this make some sense?
This is why the idea is still on the docket in my head. I'll let everyone know if/when I decide to put any money down to buy the parts.I can make you some cones that are tight and ship with the DP flanges, although i'd like to see what the expansion chamber actually does when we are forcing the air in and out of the engine.
Unfortunately, the spacing issue we have is well beyond a even a 1/2" variance that we could create with a hammer. I had another look at it with Greg last night. Looks like his memory was better than mine; even from my photos for where it's hitting the firewall they aren't quite clear. If I were to just use that existing prototype and modify it, I'd cut it off the flange and re-weld it at rotated angle bringing the bottom back about 4-5 inches.+1 The guy who built my motor in the Impala worked for JBA (makes headers among other things) and they tested out "dimples" on headers. He said as long as they were minor, they didn't make a difference in power. The exhause gas would slow down at the "dimple" and as soon as it passed it, the gas sped up which increased scavenging.
By "old tune", do you mean the tune you ran on the dyno in December?I think I'll toss in the old tune in and pull a log to see if there is a discernible difference between the two logs.
I hadn't really considered this one too much. If the restriction isn't as bad, it's possible to rig on something like dieseleux's setup, though right now, this is a bit much. I don't quite have 14" of space between the compressor outlet and the rest of the equipment in the engine to place a AWIC and loop into the intake manifold. However, it is feasible to use the space occupied by the overlaping stock IC pipes to place the AIWC... This would cut down piping length by ~4 ft too...Maybe an air to water intercooler setup? It can be mounted anywhere and make the piping from the turbo to the intake manifold shorter.
You're correct, John. I'm only looking for reducing peak temps. I'm did some more drive testing in warmer weather, ~16˚C ambient temps. Looks like the SMIC was still having a min temp of 19-20˚C. After a warmed up IC was achieved, I was able to peak it at 44˚C. This is 3˚C warmer than when the ambient temps were ~7˚C. However, any heavy driving, which I foresee as I'd like to go to a few track days once I do pistons & rods, will require better cooling.DC
You want to cool the peak temperatures, right. You are not worried about air or EGT temps in normal operations. The best way to reduce peak operating temperatures is with water injection. Water can soak up a vast amount of heat when you really need it at high boost pressures. Since you are running 25+ psi at peak boost with no bottom end upgrades and want to put off a full engine rebuild as long as possible. My suggestion - start with EGT temp monitoring so you know the baseline, then add H20 injection. Up grade the intercooler later if you need it.