Had this in the TPI section but it might be better here!

Hey guys, I am going to order the First intake system for my 69 camaro.

I currantly have a RPM cam which sounds mean as hell but since the cam isn't computer friendly I will have to change it. I will buy roller lifters and cam to go with the system but I would like to have a choppy idle or at least something you would expect from a 69.

I've narrowed down the cams I am interested in to either the comp XFI268 or the CC503. The videos of the CC503 sound great. The cars all have that choppy idle that is expected from a 69. Not sure they make a CC503 for the early style block.

The engine is a street driven 355 with 9.5 to 1 comp, edelbrock 739 heads, 1.6 rollers, and of coarse, long tube headers backed by a 4 speed and 411 gears.

I don't have too much experience with cams for the TPI's, mostly I have dealt with LSx cams, so a little help as to which would sound better would be welcome.

 

Personaly I'd go with a retro-fit rollor version of the XFI cam line, like a XFI268 or XFI280 rollor and set your idle around 500-600 for some lump, plus some decent headers and a good dual exhaust like a Magnaflow will help it sound nice

I have the retro-fit rollor XFI292 in my car right now, but I dont have a nice idle clip for you to listen too, sorry

 

I figured the XFI 292 would be too big for the company to tune. I have listened to a few clips of this cam on the net but I still think the 503 has that crisper snap to the idle.
Hawk, I noticed you ordered the First intake, what do you have now and how does it run with your cam?

 

Right now I am running N/A and I have the HSR and 58mm TB now, with AFR 195 Competition port heads, the Retro-fit Rollor XFi292, T-56 and 3:73's

This was out goofing around when we were tunning it
http://smg.photobucket.com/player.sw...fs=1&os=1&ap=1

I had the comp NX276 retro-rollor cam at first but I was fighting non stop just to get it to idle, it was fine uptop at WOT but I had to 2 foot it at stop lights, so I switched to the XFi292 and even though it is a bigger cam it held idle right away with no changes to the NX chip and was very easy for me to tune the daily driving in after, I still need to tune the PE tables for the track with the XFi292, sitting at 11.5:1 AFR at WOT but I just havent had time.

With the NX276 my best 1/4mile mph was 107, sofar my mph with the XFi292 is 114mph, I gotta get my AFR dialed in and see what I can get before compairing it to the FIRST. I think the XFi292 will be abit big for the FIRST set-up personaly.

I also have a Mini Ram comming in that I will also compair too, but setting all these up is gunna take a long time. I plan to get track times and dyno numbers. Eventualy I'll post up my results but dont count on it being anytime soon.

 

Car sounds good running through the gears. Reminds me of my 99' T/A. Sometime after the fuel injection is installed I'll start saving for the 6 speed conversion.

 

I replied in the other thread but i believe the XFI292 is way to big for a 350-355 motor. Theres guys using it on a 383-396 LT1's and its still pulling to over 6500rpm. Its a nice cam for those motors but nota good match for the first.

I still recommend the retrofit XE276HR by comp. Just like the 503, but on a 110lsa for more lope and peakier power curve. Its a good match for that motor i think

 

both the 503 and xe 276 cams are only listed for the later blocks. The closest is the XR276HR cam but the rpm range is more limited 1900 to 5600 instead of the 1800-5800 that the other 2 cams have. I would think it would sound different also.

Still concidering the the xfi 268 cam.

Honestly its either the 268 or the XR276.

 

I think the XR276 will give more lump but i think the XFi268 will be more efficient

 

Thats probly the cam i'm refering too. The retrofit cam in the XE lineup.

XR276 will do the same thing as the 503 regardless of what they rate the powerband for. That cam has abit more overlap than the 503 since its on a tighter lsa, so it may have a peaky powerband but it will produce more power at higher rpm than the 503. I think its your best bet

Other option is the XM276. Its the marine cam which is just the 503 cam. Same specs, same lift/durations, and 112 lsa.


The XFI is a tame sounding cam. Its 113 lsa and 218 duration doesnt lope much at all on a 355. But its a good cam and will make decent power, it just wont chop like you want
XR276 on a 110 will chop nicely and still be very driveable. Thats your cam

 

I think your right.

 

Here's a video of my car running....

Comp - XR276HR-12 cam

roller
.503/.510
224/230 @.050
112 LSA
108 ICA

http://www.youtube.com/watch?v=kfLWpAy0c1o

 

Nice clip, this is the cam I am going to go with. Thanks I'll save it in my favorites.

 

You'll like it :-)
Same cam here too with HSR. Idles about 750 nicely.
http://s124.photobucket.com/albums/p...trial_Park.flv

 

Interesting, sounds different in your car then the camaros. Sounds good when you hit the throttle. What does the car run in the quarter. My currant set up carburated is somewhere in the mid to low 13's.

 

The sound is because I run 1-5/8 LT headers with Pypes full 3" "x" pipe, true duals and chambered mufflers.
Would sound about the same as the Camaro if the mufflers were intended to reduce noise.
Never got any good runs in at the track with it. Just allot of noise :-)
Ran mid 14 on the street tires because I was spinning pretty much the whole 60 ft. then I short shifted into third which just killed my time.
Got a set of slicks I want to try this summer.
If I bring the idle down to below 700 it will lope really nice but i don't like the shaking from it. PITA to tune there also because the MAP keeps moving around.

 

I got mine to idle nice at roughly 800, and my map doesn't move that much at all. Pretty much stays in the same cell at idle till you touch the throttle. But, I've been tuning for several years.....

What cell or cells are in at idle or are you stuck in 4?

I've seen the map move quite a bit while a tune was stuck in cell 4 below 700......

 

im running the xr276 in my 305 and it runs great idles nice at about 900rpm and has good driveability

 

anybody have any idea what the difference in mileage might be between the xfi268 and the xr276 because I too had heard the argument that the xfi268 is going to be more "efficient".

 

Seat to seat duration will be better with the XFI268. I assume to overlap would also favor the XFI268 for "efficiency".

 

I agree with ORR. I personally do not like the 113 lsa of the XFI cam. In my opinion, I would rather tighten the lsa and run less duration. You don't need to pick a cam out of the book. Comp will custom grind a cam for just a little over the cost of an off the shelf. You may want to also look at the Lunati VooDoo line. I like the aggressive ramps coupled with good lift. The tighter lsa makes for a snappier throttle.

 

what do you guys think of the specs of this cam?
224-230, 538-541, 274-280, 112

 

Here's my 276HR-10. Mines a 110 lsa instead of a 112. It idles down to 750 about 25 seconds in.

http://www.youtube.com/watch?v=ZjzPtVme_T0

 

Whats this goin in? If you are suggesting this for the original poster then yes it wouldnt be a bad cam. Good lift numbers, I assume with 1.5 rockers? Looks like a 276hr cam with 1.6 rockers tho.

 

Its a custom grind comp cams xfi cam i bought from yenkost a while back. Ill be puttin it in my 355 SR setup. still shoppin for heads tho. Just wonderin what you guys thought about it....not sure what to expect for numbers or how it will run. lift is with 1.52rockers i think he told me. How much would lift bump up if i ran 1.6s and how much would it help performance?

 

Should work well in that motor. I love the idea of a 224/230 XFI grind and surprised comp doesnt offer it off the shelf. Run 1.6's if you can when you get good heads. Valve springs need to be stiff to handle those lobes. I like AFR's 195 heads with 8019 springs. Out of the box they seem to be the best deal going. I'm not sure what other companies are offering right now for spring choices, but before i didnt see a setup i really liked for XFI type cams

 

any idea what kind of power it might make with the 195afrs your talkin about? Im goin to do some porting on the SR aswell.

 

Similar XFI268 cam combos have done over 350whp. Depends on how ported you go with the SR