Why would you use 1-7/8" Primaries?
08-03-2010, 12:44 PM
#21
what do you think my best bet would be??? I've got 1 3/4 Primary 3" collector hooker super comps on mine now......i know its choking the motor......the engine is a Naturally Aspirated 385 w/ 13.9:1 Compression AI TFS 215 cnc heads a large Solid Roller cam 258/264 .710 lift on a 107LSA and a Edelbrock Victor Single Plane w/ a elbow and 105mm monoblade wit a fast xfi.......im thinking stepped 1 7/8 to 2" with a 3.5" Collector is my ticket? what do you think???
where did it hit peak hp with the single plane setup? pm me if you like. 
08-03-2010, 12:47 PM
#22
It's relevant with a 6000 RPM converter. Got to get that heavy sucker moving, no matter what a dyno tells you. Has to recover from gear changes also. If it doesn't really charge when it drops into the next gear, it ain't gonna be as fast as it should. We don't race dynos, flow benches, or engine modeling software. If it doesn't show up on the scoreboard at the finish line it aint' right.
The 1-7/8" Hedman Hustlers are cheaper than that. They aren't step headers, but if it wants bigger tubes a set of those will tell you. If you run open headers it could very well like extentions on the collectors. I hung 8" on the collectors and found a tenth with a powerglide car I used to race.
You need to log some passes, you want to get out of 1st gear quicker than second, but you don't want it "falling back on the converter". In other words, it should not drop back to your converter flash RPM. If your converter flashes to 5000, don't let it drop below 5200 or so. For example, if you have been shifting it at 7500, try shifting low-to-second at 7100 or so. If it drops to 5000, raise the 1-2 shift RPM a couple hundred. I shift mine at 7600 and 7200.
The 1-7/8" Hedman Hustlers are cheaper than that. They aren't step headers, but if it wants bigger tubes a set of those will tell you. If you run open headers it could very well like extentions on the collectors. I hung 8" on the collectors and found a tenth with a powerglide car I used to race.
You need to log some passes, you want to get out of 1st gear quicker than second, but you don't want it "falling back on the converter". In other words, it should not drop back to your converter flash RPM. If your converter flashes to 5000, don't let it drop below 5200 or so. For example, if you have been shifting it at 7500, try shifting low-to-second at 7100 or so. If it drops to 5000, raise the 1-2 shift RPM a couple hundred. I shift mine at 7600 and 7200.
Thanks for the help...
08-03-2010, 12:49 PM
#23
i'm thinking of doing 1 7/8"-2" stepped with a 3.5" collector... if you're running enough camshaft you're tightening up the useable powerband anyways, might as well use a header that has benefits in that rpm range especially if you're running a 5000+ converter. you're gonna have to ditch that 3" catback to see any benefits where did it hit peak hp with the single plane setup? pm me if you like.
where did it hit peak hp with the single plane setup? pm me if you like.
08-04-2010, 05:52 PM
#28
Hey quick95lt1... it peaked that high with the new single plane on there or was that with the ltx manifold? I don't know all the details such as exhaust centerline length (i estimated at 2.9"), but i did the calculator based on your old numbers and a 20% loss so ~620hp. Said 1.875-2.0xx stepped with a ~28" primary length. I'm back at work and I can't remember the length of the individual steps. Collector was 3.45-3.60 with a best length of 15.4. This was based on a 5600-7900 powerband.
08-05-2010, 08:52 AM
#29
Hey quick95lt1... it peaked that high with the new single plane on there or was that with the ltx manifold? I don't know all the details such as exhaust centerline length (i estimated at 2.9"), but i did the calculator based on your old numbers and a 20% loss so ~620hp. Said 1.875-2.0xx stepped with a ~28" primary length. I'm back at work and I can't remember the length of the individual steps. Collector was 3.45-3.60 with a best length of 15.4. This was based on a 5600-7900 powerband.
08-05-2010, 09:33 PM
#30
That was with the old LTX manifold. It may even be a bit higher with this manifold now. We'll find out im gonna get it to the dyno once its running hopefully this weekend. Thats what I'm figuring for headers....there gonna be a bitch to fit at that size and man is the price gonna be ugly lol........Yea the real power band seems to be a bit higher than that I'd say 6200-7900 or so......like i said with the old intake and a half point less compression the car made within 5rwhp from 6500-7800. Im gonna try and get some new more accurate data soon. Thanks!!!
Granted this was like 6 years ago, maybe they got with the program and fixed their design.Good to hear you're finally getting that thing done, I'm anxious for the numbers! I'll be dropping my headers in and plumbing the trans coolers tomorrow. Should be driving mine this weekend
08-06-2010, 07:50 AM
#31
I'll bet you peak 500+ rpm LOWER with that single plane and make more power. That single plane isn't going to need as much overlap to make the same power, but it will love more intake duration (later IVC). I believe taner is/was running a 2" primary 4" collector from lemons that came off of rob cowling's old blower car. Rob said they fit like ****, i guess you get what you pay for Granted this was like 6 years ago, maybe they got with the program and fixed their design.
Good to hear you're finally getting that thing done, I'm anxious for the numbers! I'll be dropping my headers in and plumbing the trans coolers tomorrow. Should be driving mine this weekend
Granted this was like 6 years ago, maybe they got with the program and fixed their design.Good to hear you're finally getting that thing done, I'm anxious for the numbers! I'll be dropping my headers in and plumbing the trans coolers tomorrow. Should be driving mine this weekend
08-06-2010, 09:16 AM
#34
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My steering columb between the joint and the plastic covering the rack hits the downpipe on the front of the hedders.
Ed probably knows the remedy a lot better than I do,there is the manual rack route or switching steering columbs.
I am looking for $500.00 if possible.
Ed probably knows the remedy a lot better than I do,there is the manual rack route or switching steering columbs.
I am looking for $500.00 if possible.