Is anyone running Brian Tooley Stage IV Cam?
I know, lol. You're missing what I'm saying. I meant running a higher static compression but the same dynamic.. And yes, I know you'd have to swap cams, I'm ignoring any power gains/losses from the cam swap, and just looking at what difference running a higher static compression would make with dynamic compression remaining the same.
You'd have same cylinder pressure but additional airflow, increasing power. From what I notice, and this is more of a trend probably than an exact science but, torque seems to be affected.
Ex. 11:1 compression
Ex. 11:1 compression
224 cam with 8.6 dcr makes 425/409 at 6100/4800
Install 230 cam numbers go to 435/398 @6300/4800 dcr at 8.3 now.
Now install .040 head gasket and scr goes up to 11.28:1 and dcr is back at 8.6.
Numbers have jumped to 439/409@6300/4800
Very random/completely generic numbers but theyre ballpark and the thought is obvious. Youre gonna trade off powerbands though gonna start a little later and end a little lated. peak rpm might remain a constand on torque but the way it approaches peak and passes peak is gonna be different.
Install 230 cam numbers go to 435/398 @6300/4800 dcr at 8.3 now.
Now install .040 head gasket and scr goes up to 11.28:1 and dcr is back at 8.6.
Numbers have jumped to 439/409@6300/4800
Very random/completely generic numbers but theyre ballpark and the thought is obvious. Youre gonna trade off powerbands though gonna start a little later and end a little lated. peak rpm might remain a constand on torque but the way it approaches peak and passes peak is gonna be different.
To me, i'd pick the cam that fits my powerband and driving style with a split and lsa/icl that matches me heads,intake, and exhaust, and id up my compression til it hit 8.7 dcr if it were mine optimizing quench first, then milling heads second. Thats just me and many argue whether its worth it, but there are no drawbacks, and nobody denies it or argues that it helps. Plenty say oh 8.4 is fine but they wont say going higher hurts. It's bothersome really. If someone wanted the most out of their used 92mm fast intake you'd reccomend them having it ported. You could tell them theres no need to bc there were 101 people that made over 450whp last year that theyre just fine. Is that accurate yes, but are they gonna go faster or slower with it after porting? My guess is faster.
Point is, you dont have to base your combo around it, but if you're looking for the MOST out of your setup, then dont overlook it bc you WILL leave hp/tq on the table and as long as you can optimize it with gasket/milling (which most all flat top piston ls engines can) then it's rather cheap power. The only thing that would make it tough is dished pistons and if youre running large dished pistons and a low scr i hope youre making positive boost.
You know thats kinda like dcr i guess. if youre running five pounds of boost on a turbo setup with an electronic controller and have the fuel/ignition system to run 10psi safely without knock or other problems where are you gonna tell the tuner to set it?? I know which of the two id pick. The 10psi and extra 65hp that came with it
Point is, you dont have to base your combo around it, but if you're looking for the MOST out of your setup, then dont overlook it bc you WILL leave hp/tq on the table and as long as you can optimize it with gasket/milling (which most all flat top piston ls engines can) then it's rather cheap power. The only thing that would make it tough is dished pistons and if youre running large dished pistons and a low scr i hope youre making positive boost.
You know thats kinda like dcr i guess. if youre running five pounds of boost on a turbo setup with an electronic controller and have the fuel/ignition system to run 10psi safely without knock or other problems where are you gonna tell the tuner to set it?? I know which of the two id pick. The 10psi and extra 65hp that came with it
There is a limit on DCR tho... it's the octane you're willing to run. 8.5:1 is plenty for 93 octane.
I would push as high as 8.7-8.8:1 but not much higher. I know some have gone to 9.0:1... but really, you need a wideband O2 and probably some datalogging software through HPTuners or EFILive to make sure you aren't getting KR on the street. You have no room for bad gas or spikes in temperature from a traffic jam (for example).
I would push as high as 8.7-8.8:1 but not much higher. I know some have gone to 9.0:1... but really, you need a wideband O2 and probably some datalogging software through HPTuners or EFILive to make sure you aren't getting KR on the street. You have no room for bad gas or spikes in temperature from a traffic jam (for example).
There is a limit on DCR tho... it's the octane you're willing to run. 8.5:1 is plenty for 93 octane.
I would push as high as 8.7-8.8:1 but not much higher. I know some have gone to 9.0:1... but really, you need a wideband O2 and probably some datalogging software through HPTuners or EFILive to make sure you aren't getting KR on the street. You have no room for bad gas or spikes in temperature from a traffic jam (for example).
I would push as high as 8.7-8.8:1 but not much higher. I know some have gone to 9.0:1... but really, you need a wideband O2 and probably some datalogging software through HPTuners or EFILive to make sure you aren't getting KR on the street. You have no room for bad gas or spikes in temperature from a traffic jam (for example).
There is a limit on DCR tho... it's the octane you're willing to run. 8.5:1 is plenty for 93 octane.
I would push as high as 8.7-8.8:1 but not much higher. I know some have gone to 9.0:1... but really, you need a wideband O2 and probably some datalogging software through HPTuners or EFILive to make sure you aren't getting KR on the street. You have no room for bad gas or spikes in temperature from a traffic jam (for example).
I would push as high as 8.7-8.8:1 but not much higher. I know some have gone to 9.0:1... but really, you need a wideband O2 and probably some datalogging software through HPTuners or EFILive to make sure you aren't getting KR on the street. You have no room for bad gas or spikes in temperature from a traffic jam (for example).
Yea, from what I read 8.5 is usually what guys shoot for. Basically when choosing a can, you want something that will put you in that ball park no matter what, right? It's kind of what dictates your duration/IVC? Then from there you choose your valve events based on IVC. LSA consequently overlap become side effects of said valve events?
I was just thinking... that the AFR 205 heads probably wouldn't like the exhaust duration on this cam. This cam is setup for a stock exhaust ports with 1.55" exhaust valves. I think it might still be fine for 1.575" exhaust valves, but I'm a little unsure of how it would react with the 1.600" exhaust valves in the AFR 205 heads.
I know we've seen the AFR 205 heads be sensitive to exhaust in some testing that I was involved with in the past. When I measured the exhaust port volume a long time ago, it seemed like it was around 88c, which is really large compared to the intake port volume.
I know we've seen the AFR 205 heads be sensitive to exhaust in some testing that I was involved with in the past. When I measured the exhaust port volume a long time ago, it seemed like it was around 88c, which is really large compared to the intake port volume.
Yes. It is an opinion that can be easily found and researched on this site.
The profile has been long proven in the LS1 and even LT1 world. The 234/242 makes power. G5X3 is the most famous of these profiles. Look up the G5X3/AFR 205 combos that used to do 490-510rwhp.
And Brian's cam did 517rwhp uncorrected with TEA LS6 heads on a 346 using basically the LSL/XE lobes he is selling as the Stage IV. I think the LSA/ICL might have been different but similar.
Yes, it uses LSL and XE lobes. The combination works due to the added seat to seat duration on the exhaust lobe keeping the exhaust lobe open longer during the overlap cycle, allowing the intake charge to be pulled through the exhaust.
The profile has been long proven in the LS1 and even LT1 world. The 234/242 makes power. G5X3 is the most famous of these profiles. Look up the G5X3/AFR 205 combos that used to do 490-510rwhp.
And Brian's cam did 517rwhp uncorrected with TEA LS6 heads on a 346 using basically the LSL/XE lobes he is selling as the Stage IV. I think the LSA/ICL might have been different but similar.
Yes, it uses LSL and XE lobes. The combination works due to the added seat to seat duration on the exhaust lobe keeping the exhaust lobe open longer during the overlap cycle, allowing the intake charge to be pulled through the exhaust.
Okay, I have a question. I understand the whole "over-scavenging" thing now that my setup is doing this. I lost power up top after switching to larger 1 7/8" headers, and it's likely due to over-scavenging. Brian is right on with what he said about his Stage IV cam probably not being the best for the AFR 205cc heads due to "over-scavenging" and the possibility of losing power up top. The AFR heads have a big exhaust port and valve and the exhaust flow of those heads are far more than 95% of other ported heads. So here is my question. Why does the G5X3/AFR 205cc combo make such good power, especially up top? The G5X3 cam is virtually identical to the BRT Stage IV cam.
A lot of guys have started using more and more exhaust duration. In the real world, it helps power hold on past peak at the expense of some mid-range power. So if you optimize your valve events to push to a 6600-6800 peak HP (even with like a FAST trying to hold it to 6300), the added exhaust duration would help you push out past 7000-7200 without losing much.
