LT1-LT4 Modifications 1993-97 Gen II Small Block V8

XFI cam vs. GM847

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Old Apr 3, 2007 | 02:50 PM
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Default XFI cam vs. GM847

ok so.... i'm about to upgrade my hotcam to something bigger. I have seachered the GM847 for awhile now, but I recently started researching the Thunder Racing Comp Cams XFI LT1 Camshaft, 242 / 248, .584 / .579 113 LSA.... and I was wondering what you guys have to say about it in comparison to the 847. Like how it performs, HP output, stuff like that.... anything will help.....
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Old Apr 3, 2007 | 05:24 PM
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what size motor???if it's a 355 i would get the 847.
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Old Apr 3, 2007 | 08:59 PM
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Either way both cams are made by great companys and u will see a gain with switching cams, i would call Thunder and and ask them for some insight on power numbers and driveablity. I've never seen Thunders XFI cam with a combo but the 847 and ur heads would be a nice combo.
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Old Apr 3, 2007 | 09:18 PM
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Originally Posted by raymond mckinney
Either way both cams are made by great companys and u will see a gain with switching cams, i would call Thunder and and ask them for some insight on power numbers and driveablity. I've never seen Thunders XFI cam with a combo but the 847 and ur heads would be a nice combo.

yeah thats pretty muchh what i was thinking.... i'm sure i would probably see around the same gains with both cams considering they're similar...
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Old Apr 3, 2007 | 09:19 PM
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Originally Posted by vanilla89
what size motor???if it's a 355 i would get the 847.

no... its still a 350ci.... but all forged internals...
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Old Apr 4, 2007 | 12:41 AM
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any head/valve train work????
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Old Apr 4, 2007 | 01:45 AM
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I have that XFI cam. I have ordered a custom ground cam from Bret Bauer. Needless to say I don't like the XFI cam much...
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Old Apr 4, 2007 | 02:34 AM
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I have the GM847 with my LE2 heads on a forged 355....it feels like you are using spray when this cam gets to 3K. LOVE IT. I turn to 6.8K ,pulls all the way with me
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Old Apr 4, 2007 | 04:11 AM
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I have the 468 XFI cam, feels pretty strong to me, but then again my previous cam was a 230/236. So who knows...feels good to me, plus I just smoked a 420 hp LT1 with a Bret Bauer cam...
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Old Apr 4, 2007 | 06:36 PM
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Originally Posted by siniSSter
I have the 468 XFI cam, feels pretty strong to me, but then again my previous cam was a 230/236. So who knows...feels good to me, plus I just smoked a 420 hp LT1 with a Bret Bauer cam...
what mods
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Old Apr 4, 2007 | 09:01 PM
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The XFI grinds get a lot of press but I have yet to see good RESULTS from them. Lots of guys pushing them some guys using them and every case I have seen has been mediocre to poor performance.
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Old Apr 4, 2007 | 09:13 PM
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^Agreed. Mine sucks. I can't wait to get a cam matched for my combo.

What is funny about a Bauer cam siniSSter?
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Old Apr 4, 2007 | 11:49 PM
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What is funny about a Bauer cam siniSSter?
Nothing funny about a Bauer cam, I'm actually considering getting one of his custom grinds (heard very great things about him). I just personally never like the low LSA he uses. Everyone seems talks bad about the XFI, but yet mine seems to be working great. The car I raced runs good and tunned to perfection, just that my setup is a home built LT1 383 with crappy heads and my car pulls his about a car. Hey fergy why do you say the cam sucks? Judging by your sig, I would presume you would be over 400 hp.

Last edited by siniSSter; Apr 4, 2007 at 11:54 PM.
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Old Apr 5, 2007 | 10:58 AM
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how low are his LSA. a guy I know I think he has a 107 LSA and wants to spray N2O....is that even safe (probably like a 100 or 125 shot)
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Old Apr 5, 2007 | 11:57 AM
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I think a 107 is way to tight to use spray, I'd say 112+ for anything over a 100 shot
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Old Apr 5, 2007 | 12:29 PM
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Originally Posted by DroppedM6Z
I have the GM847 with my LE2 heads on a forged 355....it feels like you are using spray when this cam gets to 3K. LOVE IT. I turn to 6.8K ,pulls all the way with me
I have a GM847 on my stock bottom end car with Combination Motorsports Stage 2 heads. I agree with the powerband... it feels peppy down low, and then goes INSANE above 3K.

Still gets 24mpg highway too
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Old Apr 5, 2007 | 01:25 PM
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The reason i believe the guys say the camshaft sucks is because of the CI of the motor they are running it in. Seems to me the 383's really wake up with that camshaft. I will give a write up on it as soon as i can get mine together and to the dyno. I ran a Linginfelter 219 219 525 525 on my 383 with homeported heads and SuperRam intake from Accel made 350 RWHP and over 400 ft lbs. Automatic 3200 stall 10 bolt. Did not rev past 5500 because my powerband was over. At 2500 there was 300 ftlbs of tq.
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Old Apr 5, 2007 | 01:50 PM
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You could be right, I have a 383 setup and the cam feels pretty strong on my car. I havn't had my car dyno tuned, but I feel it should put down over 420hp.
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Old Apr 5, 2007 | 02:24 PM
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Originally Posted by DroppedM6Z
I think a 107 is way to tight to use spray, I'd say 112+ for anything over a 100 shot

yeah the 847 is like 112 i'm pretty sure, and i was thinking of a 150-200 shot on top of it.....forged bottom end so why not right!!!!
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Old Apr 5, 2007 | 11:50 PM
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Nothing funny about a Bauer cam, I'm actually considering getting one of his custom grinds (heard very great things about him). I just personally never like the low LSA he uses. Everyone seems talks bad about the XFI, but yet mine seems to be working great. The car I raced runs good and tunned to perfection, just that my setup is a home built LT1 383 with crappy heads and my car pulls his about a car. Hey fergy why do you say the cam sucks? Judging by your sig, I would presume you would be over 400 hp.

It may not suck, it sucks for me though. I am still on stock cubes so I would have to make it rev to the moon to make peak power. We just cut it off at 6800 and it shifts at 6300. Comp recommended the 918 springs for it, and they were installed at the recommended installed height, and I still seem to be getting a little float. There is also probably room for better tuning, the car doesn't run good at part throttle and runs decent but not great at WOT. I dunno, the cam is just not good for my combo. I shouldn't have said the CAM itself sucks, because that is probably not the case. I know I picked the wrong cam for my combo, I didn't do my homework till after it was in the car and tuned.

edit: forgot quote
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