Mikelly Posted December 17, 2001 Share Posted December 17, 2001 Well after over a month, I called ISKY Cams back and got their recommendation for my current configuration... I have two choices... Go with a cam one size down and take a 5% power hit, or get a set of 3.9-4.11 gears for the rear of the car... They recommend the gears, and they also claim that going to programable FI MAY fix my surge problem anyway, but I should still run a deeper gear... So now I'm looking for a 4.11 gearset for my Clutch type LSD unit... Lovely.. Mike Quote Link to comment Share on other sites More sharing options...
John Scott Posted December 18, 2001 Share Posted December 18, 2001 Yeah!! Thats the direction to go. I bet that will fit your tranny ratios better, as well. JS Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted December 18, 2001 Share Posted December 18, 2001 Mike, Is the choice of rear gears or cam's gonna also be your final choice for your car when you decide to run it the road race you've been itch'n to run in? Top end speed (your 200mph goal) usually comes easier w/smaller cubic inch engine & smaller gears (highway gears). Just thinking outloud. Kevin, (Yea,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
John Scott Posted December 18, 2001 Share Posted December 18, 2001 Mike's 2.66 1st gear with the 4.11s (10.93) will similar to a 2.95 1st with 3.55s (10.47). His .5 6th will still only be 2.05 with the 4.11s. Plenty of room for top end blasts. I think 200mph will occur around 55-5600. I think its a great match for the cam and transmission. JS Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted December 19, 2001 Share Posted December 19, 2001 Correct me if I'm wrong (& it wouldn't be the first time) but you're assuming a 100% VE...and 100%VE engines rarely occurs: especially at the 6000-6500rpm range. Even if his engine were running at 90%VE at that rpm Mike would still have to push it to the 6250rpm level to reach the 200mph mark and if he were running at 85%VE then he'ld require 6600rpms to reach his 200mph goal (assuming his engine is putting out 500hp at that rpm & rear tires of 24.58"Diameter). My suggestion I'm hinting at is this: is the desired 200mph going to be a quick spirt that once reached is only maintained for a short time then the car comes back down to the 150-160mph range or will the race indicate a flat wide open 180-200mph required speed. The reason I'm asking is wouldn't it be better to have an engine w/a smaller stroke for high sustained (Constantly Sustained) speeds as opposed to a large cubic inch engine w/a long stroke? I know the 383's are great torque monsters...for the 1/4 mile tracks: but is the 383 capable of living at those "Constantly" High Sustained Speeds. I guess what I'm asking about is Long Term Endurance/Durability (no thrown rods...ect, ect) and instead of the 6300-6600rpm Sustained RPMs why not 5500-5700rpm's (which includes the unknown 85-90% VE) and would lower temp's not only in the engine but also in the rear diff/axle. Again, only thinking outloud as I too would like to see Mike reach that 200mph mark w/out complications. Kevin, (Yea,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted December 19, 2001 Share Posted December 19, 2001 What are you referring to with the abreviation "VE"? Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted December 19, 2001 Share Posted December 19, 2001 "VE" stands for Volumetric Efficiency in ref.to the efficiency not only of the air thru the engine but also the power loss due to the driveline (power from the flywheel to the tires/ground). Its theorized that automotive engines never run at 100%VE unless untold man-hours (which means Dollars $$) are involved in fine-tuning (Porting, Grinding/Manipulating) all passages of an engine to perfection: as well as the power loss in the driveline going from the flywheel to the hp/torque actually put to the wheels (which should be less due to the %VE being less than 100%). So in an attempt to determine power output of an engine (if you accept the %VE argument) you have to over-achieve your actual hp/torque goal on the dyno in order to reach your actual hp/torque goals on the street (with the engine in the car)once you've determined or "assumed" the %VE your engine & car is running at. Kevin, (Yea,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
Mikelly Posted December 19, 2001 Author Share Posted December 19, 2001 Well here is the issue I'm facing: I won't be allowed to go out and run the unlimited class the first and possibly the second time out at ANY of the events I'm aware of. You must first prove yourself to be safe, follow the rules, and prepare a suitable car. My first class qualification effort will be in the 135MPH zone. So if I'm able to have the car ready by this coming October (2002) then I won't be running the 200MPH class anyway. Realistically I may end up getting rid of the T56 and opting for a Richmond 6 speed for the custom gear selections... Who knows.. Still sorting that out. As for the issue with the 383, many guys are running them all day long in these and other events... I'm having my rotating assemly balanced and will look at beefing up the lower end in areas that will allow me to rev to 7000RPMs... Mike Kelly Quote Link to comment Share on other sites More sharing options...
Guest Fast Frog Posted December 19, 2001 Share Posted December 19, 2001 Well, whatever-you just go for it Mike!! BTW, what are the cam specs you're looking at with this Isky cam?? Rick Quote Link to comment Share on other sites More sharing options...
Mikelly Posted December 19, 2001 Author Share Posted December 19, 2001 Specs on the cam can be found Here: http://www.iskycams.com/CGI/Search_1704?sort=racesearch_price&category_id=3193&category=3193&kit=&skip=1&cat_id2=&description_id=1704&opt=id&action=Display+Products&attribute1=9045 &engtype=93&application=0&opt=id&do=Try+Again Cam number is 201282294. This is the cam I currently have in the car... Mike Quote Link to comment Share on other sites More sharing options...
John Scott Posted December 20, 2001 Share Posted December 20, 2001 Regardless of the actual capabilities, my predictions were based on the formula: Engine speed=mph x final drive ratio ____________________________________ tire OD(inches) X 0.002975 Vipers and Corvettes with less hp are are pushing some pretty high speeds. Also, 383s can be built to run well into the 7000s, all day long, if you got the $$. Dont over look the rods! JS Quote Link to comment Share on other sites More sharing options...
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