S480-383ltx back in the game cam guru needed!!

[BOOST-ADDICT]

Need a new cam spec'd out. Motor specs...
383ci 9:5-1 currently being rebuilt all forged bottom end
AI LT4 215cc 56cc 100% cnc 1.6 Dr
Ported and polished Ltx intake/58mm Holley tb
Th400 rmvb stall (undecided)
Moser 12 bolt 4.10 switching to 3.23-3.42
Going e85 120lb injectors
Efi 24x conversion
Forced inductions s480 t6 1300hp rated
I currently have a boost cam from old set up but that was a 67mm t4 and smaller 190cc heads. So need some help on who I can go with to get the maximum out of my new combo. Could just stick the old cam in and save some money but since this thing is apart and a whole new combo not sure what to do. Thanks guys!!

[dawdaw]

I think it would be in your best interest to call AI, the guys that did your heads and have them grind you a came so you can maximise the set up... Call PTC up and have them make you a converter :) welcome to the site as well!

[Ryan Stout]

What's the specs on the cam you have now? Mine isn't big at all and it works very well.

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[Ryan Stout]

Mines .575/.575 224*/224* 114lsa. Siunds stock but it the car loves RPM.

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[CamaroZGuy]

mine is spec'd for lower boost supercharger but its a .576/.606 224*/236*@.050 114lsa

spec'd out by LE

[BOOST-ADDICT]

Well can't find any info on old cam I took a pic and sent it to Martin at tick he said no luck. I can't load a pic from phone but here are the numbers scribed on it
290HR14
First number/letter is messed up on next one
S or 2 23552...thinking maybe 232 552
This cam with untouched old style AFR 190cc
383ci ,t56,Sts turbo kit 67 trim on pump gas made 634hp 654tq to the wheels with a ton a back pressure.

[BOOST-ADDICT]

At 11psi..sorry

[popo8]

Id normally say contact Lloyd Elliot...but since ur runnjng AI top end... Stick with them.

Co-Owner/Admin @ LTXtech.com

[BOOST-ADDICT]

Well I bought the heads from a forum member so I can talk to them (AI) since there right outside Charlotte n.c. (35mins) from me. Just curious if I should keep the old cam or spend $350-400 for a new spec'd cam. Thanks!!

[CamaroZGuy]

let me see if i can scrounge up the emails from LE when he was explaining boost cams. its a real good read.

[firebird_1995]

Fwiw Lloyd sells his cams for $300 shipped. Mine is 223/234 .575 lift

[CamaroZGuy]

If we have 9-9.5 to 1 compression and 15 lbs of boost or less, the 224/236 .560/.576 114 LSA cam will work GREAT.

15 lbs of boost, we can use a 230/244 .598/.608 114 LSA cam and make KILLER power from 6000-7000 RPM. This cam would be about 20 HP down at 4500 RPM and about 40 HP down at 3000 RPM compared to the smaller cam mentioned above even at 15 lbs of boost. If we have less boost, this larger cam will work even worse.

Boost doesn't require much cam duration at all to work well



the smaller cam is more efficient with low boost and at lower RPM. The big cam works better when more boost is cramming the cylinders and at high RPM.

Overlap is when the intake and exhaust valve are open at the same time. Overlap and boost do not work well, it allows the boost to go out the exhaust valve instead of packing the cylinder and building boost.

The larger cam has 14 MORE degrees of overlap than the smaller cam so there is more boost lost out the ex valve and builds less boost. The larger the S/C and the more boost you create, the more you can get by with wasting out the tail pipe "assuming you are gonna spin enough RPM to actually use the gains of having the valve open longer with more duration and make the smaller cam limit cylinder filling".

The larger intake duration also keeps the intake valve open longer and you don't actually start trapping cylinder pressure until the intake valve closes. This is another reason that the smaller cam helps with lower boost set ups. It starts building boost sooner (less overlap putting wasting boost by going out the tail pipe and closes intake valve sooner so it starts trapping cylinder pressure sooner) so you make more HP/TQ at EVERY RPM up to 5500-6000 RPM where the larger cam will actually make the same HP and then surpass it and "can be" 20 HP better at 6500 RPM and "can be" 35 HP better at 7000 RPM.

Now when I say "CAN BE" above, I am talking about the potential of both camshafts only and to see these gains it will require no other restrictions in the set up. as long as you have a larger enough air inlet, MAF, duct work, TB size, fully ported intake, etc so that ALL of this can keep up at this RPM/HP level . . . . . . . . . . . AND a good enough cylinder head, header and exhaust system that can keep up at this RPM/HP level, it is "possible" to see these HP gains.

If trying to use a the stock S/C air inlet, F body MAF, factory elbow, un ported intake, 1 3/4 LT's, ORY and cat back exhaust, you will NEVER see this kinda gain at high RPM due to each and every one of these things being the restriction. If the heads are less than 2.200" at the pushrod pinch and less than a 2.08 intake valve, it will never show these gains with the larger cam at high RPM, even if you do have everything else that is free flowing.

SO, in order to see the gains at high RPM you will need a custom air inlet, duct work, MAF and elbow that allows ZERO difference in boost when checked at these points compared to boost in the intake.

You will need a 58 MM TB, fully ported intake, 2.08 intake valves, FULLY ported AFR 210's opened up to 2.200-2.400" at push rod pinch (if starting with an LT4 intake we can actually get 2.400" here), a set of 1 7/8 LT headers, 3" True Duals with X pipe, Bullet mufflers and dumps at rear end.

THIS set up would actually be able to see the 20/35 35 HP gains at 6500/7000 RPM over the small cam BUT the smaller cam will still make the same HP at 5500 RPM, 20 more HP at 4500 RPM and 40 more HP at 3000 RPM.

If you do not have all the parts mentioned to see the the gains at high RPM, there will be very little to no gains up there with the larger cam and so you might as well take advantage of the extra HP/TQ thru the entire RPM range of the smaller cam.



now this was explaining cams for my specific setup but its a good read.

i will say, talking to Lloyd he has almost made my head explode with knowledge!

[BOOST-ADDICT]

Thanks..very knowledgeable!!