i know its a vette forum but theres alot of smart people here so. is a cc305 cam better than a lt4 hotcam? also how does it compare to a cc306? need to pass emissions but want more power. have lt4 hotcam 1.6rr port polish stock heads intake and 355cu. thanks guys

 

wont notice much of a difference between the two. comps 503 grind, another popular LT1 grind should show abit more power and torque over hotcam but all 3 are within 10 hp of each other depending on tune/exhaust

CC306 is much bigger and would make more power than all of them but it wont pass emissions without a heck of a tune and some help from a cat and other tricks ppl use.

 

so if i want to have a noticable difference the 306 would be the best best with a big tune?

 

If your state emissions testing is just checking for emissions codes, you can tune the 306 to pass. If you have to pass a tailpipe sniffer, I doubt the 306 will pass even with the best tune.

 

I run the CC306 in my 383 and I would say that I wouldn't fancy it none in a 350... its big/tempermental enough in the 383.

 

I have a CC503 in a 350 with HSR intake. It is a little "tempremental". Get a cam surge with the converter locked when in OD and rpms are less than about 2200. If you want any street manners I wouldn't go with a CC306 cam in a 355. But, if you are looking for mostly track use and have the converter, gears and intake to go along with it then by all means do the CC306. Your bottom end will have to rev pretty high to use the powerband of that cam in a 355 though. If you can live with a small amount of cam surge do the CC503. If you want near stock street manners do the LT4 hotcam. All this is assuming you are not talking about a TPI intake. If you are, even the hotcam is too big in my opinion.

 

With the right tune you shouldn't be getting cam surge with the 503. I am running a higher lift version of the 503 (224/230 605/622(1.6) 112), and can cruise the car around at 1100 rpms as smooth as silk.

 

I'm not going to worry about it any further because I'm putting in a 383 with a 230/236 cam, project starting next weekend. But if I weren't I'd be interested in your tune. Jesse Azzato has my tune all but perfect, but that light cam surge is still there in the lower rpms when the converter is locked. Can't feel it when the converter is unlocked. Pcmforless did the tune originally but the cam surge was much worse, the idle was worse, and the power was down a little. Jesse did a tune for it and got it almost spot on first try. He did a reburn and that is what I run now. I have a wideband 02 gauge and he has the WOT, the cruise, and the idle spot on. Most everyone I've talked to running the CC503 cam go to lower rear gears to help eliminate the surge, by keeping the rpms up. It only does it at very light throttle, very light load conditions. Feels like a cut out. Anyway, for the OP, I wouldn't suggest anything bigger than the CC503 for a 355 unless you aren't worried about street manners.

 

you guys mentioned cam surge with a converter. i have 373 and a 6sp. do you still get the surge?

 

Part-throttle is the most involved part of tuning. That's why it is so hard to get perfect over the internet or mail. WOT tuning is a piece of cake.

 

IMHO, if you can find a way to have it dyno tuned... do it. The tuner will be able to address the part throttle, WOT and idle issues collectively. You're @ 2 hours of ECS and a few others that should be able to tune it.

Call first, many don't tune LT-1's any longer.

 

I also get a little cam surge with the 503, but it only occurs at 1500 rpm. 1400 rpm and below is fine, 1600 rpm and above is fine.

I notice it while in 4th OD (4+3) in a light load cruise which happens to be right around 50 mph with my 3.73 gears and 0.62 MH5 OD . I use this gear often to minimize the blower discharge/inlet air temperature, but I can easily drive around the surge.

I suspect that the extra SR plenum volume also plays a contributing role in the phenomenon.

 

What heads? What intake? Exhaust? If you are already running the LT4 hotcam if I were you I'd stay with it. If you need to pass emissions you can't go much bigger I don't think. Not an expert on that though. If you are running a TPI intake then you need to swap that out to pick up horsepower. If you are already running an intake that makes you and your hotcam happy then maybe it is time to go to aftermarket heads. Your exhaust might be holding you back too, if it is stock. Let us know the whole setup you currently have.

 

I had always considered dropping down to a 1.5 rocker on the exhaust side to see if that would help keep the cylinder pressure up some and maybe alleviate the surge.

 

360 rwhp
Ported and polished stock heads, intake and throttle body.
LT4 hot cam with 1.6 RRs.
.030 forged pistons
SLP ceramic coated shorties.
Stock y-pipe and cats.
Borla catback.
Trifecta tune.


Drivetrain
New Spec stage 2 clutch and billet flywheel
Strange S-60 with 3.73s, 35 splines and detroit true trac.
Speed inc nitro drive shaft

 

That's pretty good power considering the mods!!!

 

That is pretty impressive, who ported and polished the heads? Is that a mail order tune?

 

thats another thing that gets me. i have the dyno graph showing 360rwhp but i cna only manage 13.3 @ 107, granted 2.4 60ft(driver mod i know! 1st and only time at track in july heat) but a 355 with 360rwhp. the car may have 12.8 in her but....The previous owner did the mods so theres another ? but have found him on another site and agreed with what has been done. thats y i want to upgrade the cam. long term would be to go LE2 or 3 heads and then turbo or SC.

I have the reciepts to the heads and intake . it was a shop in New England. cant remember name. trifecta is kinda a mail order tune. http://www.trifectaperformance.com/order.aspx

 

360 rwhp, on a dynojet I assume? That's about 310 on a loading style (Land and Sea or Mustang) dyno. That would be about right, IMO.

Going much bigger with the cam will cause the cam surge, you will need to stay in a gear that keeps the rpms up to stay away from it. You might be able to go a little bigger with the cam but I don't think you would gain enough to be worth the work and money, especially since you have to pass emissions.

Seriously, put a nice wide set of Nitto drag radials on it, set the psi to 22 to 24 psi. You will be amazed at the gained traction. They are way stickier than any street tire on the street and they handle and drive well. Heat them good at the track and they are like glue. Any tire that is better than the Nitto at the track, IMO, isn't very stable for continued street use. Do some adjustable shocks or something to help if you still need more traction. I'd bet your setup can get to 1.9 or maybe 1.8, with a dead hook maybe a 1.7 60 ft. Mid 12's are yours if you get it hooking. Your money and time will be much more productive for you in tires/suspension then it will be in a cam swap.

IMO, LT headers would pick you up some ponies too.

As a rough point of reference, my current combo is a CC503 cam, HSR intake, reworked 113 casting (stock vette) heads, 10.1:1 SCR, 2800 stall converter, 3.07 gears, Nitto drag radials, lots of other supporting mods. I only made 1 pass on motor, lauched fairly easy and dead hooked, it was a 12.95 @ 105 mph. Car weighs roughly 3300 without me in it. Gearing is not nearly optimized, and I have bad blow-by. Just by re-ringing the motor I'd bet I could get a 12.7 or a 12.6. I'd bet with a dead hook you would run that or better with your current setup.

Are your pistons forged? If so, spend $800 on a Zex nitrous kit and a bottle heater. Put the 125 jets in, spray it after launch, and pick up a full second in the 1/4. Put in 200 jets and pick up 1.5 to 1.75 in the 1/4. If your first gear is a bear even on drag radials, don't push the button till after you shift to 2nd. Just another option that works for me so I'm throwing it out there to you.

 

Definately agree with the Drag Radials. My personal favorite is Nitto, but I haven't tried them all yet. BFG hooked a little better cold than the Nittos, but wore out after only 3,000 miles. That's too fast for a street car in my opinion. The Nittos lasted over 10,000 and hooked just as well when warm.