supercharged SBF cam recommendation?

[sagec1001]

Hello all!

I have a 94 mustang gt and we are rebuilding the motor here in a week. i already have a p1sc procharger on it w/ 2 core intercooler with about 15 pound pulley. we are putting probe/scat 306 rotating assembly in it w/ reverse dome pistions -15.3cc for about 8.2-1 compression. the top end will have twisted wedge 170cc heads good to .600 lift and the track heat intake. I'm torn between the blower cams on the site here. all have the 114 lobe, so that's good. I've been recommended to use the 276HR (#35-312-8) but i'm not sure if w/ the .560 lift itll work with the pistsons i'm going to use..no reason it shouldn't but i hate having to exhange stuff and just want to do it right the first time. I'm personally interested in teh 284 HR (35-306-8) which says is good w/ heads, intake, headers. anybody have any opinions on a different cam i should use for my blown car, and maybe why one is better than the other? or even if you have feedback on the pistsons and clearance using the .560 lift cam! Thank you all!

Cody Sage

[amick]

What transmission and rear end gear will you be running in this setup? As far as PTV clearance goes there is no way to know without putting it in and checking it. I would expect you to have clearance on a cam of that size without and issue but you would have to put it in and measure to know for sure.

[sagec1001]

Currently the car has the T-5 and stock 3.08 gears. The gears will be updated to 3.55 when the funds are avalable for that..more than likely immediately after the motor is done. The transmission will remain the T-5 until it no longer works.

[amick]

I would actually go with the part number 35-552-8 in this setup.

[sagec1001]

Any specific reason? It looks like it is meant for a lower rpm range, which i'm assuming is why it was chosen because i'm running pretty wide gears, even when the 3.55 gears are put in. Is there any other reasons that i should consider this cam? I'm trying to learn all there is about cams, so it's an inqury for informational feedback, i suppose. Just curious what makes cams work well with certain parts and poorly with others.

[amick]

There are multiple reasons why this is the cam I would go with. First you have a smaller engine so going with too much cam will really kill bottom end torque and throttle response, which will kill the fun factor of driving it. The RPM range of this cam will also be higher with your better flowing heads and the spercharger. This cam also has a longer split between the intake and exhaust duration which will work better with the supercharger. You could run any of the cams you mention and they would all work pretty well. I think you will like the one I selected for you the best. If bottom end torque and throttle response are not a concern for you I would step up to the 35-556-8. This cam will make more power but it will do it in the upper RPM range. Basically what I mean by this is the larger cam will run a faster time at the track but it will feel slower when you drive it on the street. It is just dependant on what you want out of the setup as to which one is the right choice for you.

[sagec1001]

When you say split your talking in regards to the difference between intake/exhaust..so for instance the 284HR blower has a split of 6 degrees whereas the one your are recommending has a difference of 12 degrees. Is there a certain point where the amount of difference becomes counterproductive or is this one of those things that heavily depends on the other specs of the cam? The cam you recommended would be best for hte street..would it also give the highest average HP/TQ throughout the band? Would you also recommend either of the nitrous cams before any of the blower cams? If i was to say i was torn between the larger blower cam, and the 284HR, which would you say would perform better? Thank you for dealing with me and helping me!

it is much appreciated!

[amick]

The larger cam I recommended will make the best overall power and torque number. You will just have to turn the motor a little harder to get it in its RPM range. The smaller cam I recommended will be the best compromise between power and drive-ability and produce the best bottom end torque and throttle response. When I say split I do indeed mean the differance between the intake and exhaust durations. The is a point where the split gets to wide but it depends on the application the cam is going in. I would also recommend both of the NX cams before either cam you suggested. All four cams will work and we are talking about small differances between all of them. I do believe the two NX series cam I recommend will make better power and torque than either of the two cams you suggested in the begining though. The reason is the NX series cams are a newer design and have a more aggressive lobe profile. Bottom line is you can run any of these cams and still make good power with this setup and drive it on the street.

[sagec1001]

Okay. 35-556-8 wins my vote.. The special instructions associated with the cam state:
[2] Requires machining on cylinder heads.

what exactly is needed to be machined on the on the heads to be compatible with this cam? The heads that will be used are Trick Flows TFS-51400004

[iwannagofaster]

You should not need to machine anything on the aftermarket heads. That note is mainly for stock heads.