I currently have an xr275hr cam waiting to go in my 99z28. Should I have went with the larger xr281hr? I plan on running this cam with comp cams 1.82 high ratio rockers. I primarily drive the car on the street, it is at the dragstrip 3-4 times a summer. Mods I plan on doing with the cam: Fast 102mm intake and TB, CNC ported LS6 head with 5 angle valvejob and Dual springs, ARP rod bolts(for spinning around 7k rpm), Fast Fuel rails and bosch green giant injectors, and walbro fuel pump. Rear end is a 9" with 4.11 gears. Thanks in advance for your advice.


Eric

 

I could also go with the XER273HR, seems to be the same as the xr281 but with a 114 LSA instead of 112.

 

Most likely aren't familiar with comps cam specs right of hand. Can you list the specs of the cams in question so we can see them in this thread?

 

XER273HR
http://www.compcams.com/Company/CC/c...csid=1092&sb=2
XR275HR
http://www.compcams.com/Company/CC/c...csid=1090&sb=2
XR281HR
http://www.compcams.com/Company/CC/c...csid=1091&sb=2

I really like the first one due to the fast it is nitrous and blower friendly but what do you think? will it be to large of a cam with the 1.8 ratio rockers?

 

Do you already have the rockers? Most cams are designed to be only ran on 1.7s.

 

No I have not ordered the rockers yet. would i be better off with the 1.72s?

 

just use your stock rockers,maybe upgrade the the trunnion bearings.if you can find a used 92mm fast you can use your stock fuel rail.get a 92mm TB if you get the 102mm intake.what converter will you use?

 

I have a 6-speed. The car is not a daily driver, but it does spend most of its time on the street, track 3-4 times a year. not sure which cam will benefit me the most. obviously looking for the most streetable HP. Thanks

 

eh i'de look at somebody else's cams. ie: TSP, TR, SI, vengeance, cam motion, etc. not really a fan of the comp house grinds.

but if you went with one of those i'de say the XE-R 224/230, even then i'de still look at a bigger cam for what you are doing.

 

yeah I think im going with the xer, never know when I might come across a nice blower. and this is the only cam thats blower friendly.

 

Good advice right here. As far as the cams...

XER273HR
224/230 .581/.588 114 (That is .622/.630 lift with 1.82 rockers btw). "RPM range 2000 - 7000."

XR275HR
222/224 .566/.568 112 "RPM range 1800 - 6800"

XR281HR
228/230 .571/.573 112 "RPM range 2200 - 7200"

Where do you actually want to make power, and are you going to stay NA or go with a supercharger? I don't know that I would get any of these for a primarily street driven car.

 

I like the possibility of s/c or nitrous in the future. So none of those cams are DD friendly?

 

If it was me, I would pick XER273HR

 

Not exactly what I meant. There are other cams out there with different lobes and specs that may make more power in the RPM range you see on a daily basis with more DCR, etc...