hey guys ,


can i run a gm 847 on a 355 with NX?

 

local board member in my area is running a 355 with gm847 with t350 trans, and homemade ford 9"..........on motor he ran 11.5 @ 119........on a 175 shot he ran 10.6 @ 129.

btw, that is on a mail order tune!

 

My buddy is running a 355 with a GTP-6 cam, which I believe is identical to the 847. He's ran 11.4 on motor and 10.3 on a 150 shot.

Frank

 

seems to be a hard 'off the shelf' cam to beat!

 

I'm about to do the same thing.

I've just finished the rebuild, forged crank, h-beam rods, and forged floating pistons, GM 847 cam, home ported heads.

Getting ready for the 150 shot. I've already bought the kit, now I need to hook everything up.

I'll let everyone know what happens. (prob. be a couple weeks)

D Moss

 

Yeah as got hp said I was running the 847 with a 175 shot on my forged 355 and now have moved on to a 250 shot.The cam seems to like the spray fine.

 

n20ta2: i was thinking about going with that cam in my 355. what is the rpm band like on it and who did your tuning on it. thanks

 

What about a GM 847 with a 110 LSA in a 383?

 

I know if I had to do it again, I'd definetly get mine cut on a 110*. I've got a friend who has an old truck with a 3/4 race cam (248/248, .490 .490 lift, and 110*LSA) and that is the best sounding street car around here. He isn't the fastest by any means, but the sound......daymn.

Of course his is just a flat tappet where ours are roller, so we still wouldn't have quite as much overlap time (talking about fractions of a second here), but it still should be close.

D Moss

 

95firechicken n20ta2: i was thinking about going with that cam in my 355. what is the rpm band like on it and who did your tuning on it. thanks



My rpm band is good from about 2000 all the way up to 7000 rpms, no valve float and it doesn't slow down enroute to the 7000rpm mark. IT PULLS HARD.

I do have the M6, so if you have an auto with a stall, you don't have to worry about low rpm take off anyway, but mine is sweet. I have an idle set at 850 rpms (I like the chop) and starting off with the manual is not any different than normal.

Now I can't put it in first and let it idle in gear, but from 1000 rpms and climbing isn't any problem. The car doesn't like cracked throttle postitions at low rpms, but I don't drive 5 mph anyway. (it will chug like a tractor, but so would my XE224/230) I'm usually at WOT anyway.

D Moss

 

It pulls real hard up to 7000 rpm no problem it would spin higher but I like to stay on the conservative side.I had my tuning done by pcm for less.

 

I'm am the one that Frank (12secZ) is talking about. I have a gtp-6 cam which is very similar to the 847 235 242 .568 .592 112lsa lift with 1.6 rockers. I run the times in the sig and I shift my car at 6200rpms. It will make power up to 6800 but I do not like to rev mine that high as it doesn't run any faster and it is more stress on the engine parts. I have a 4500 NA 5300 on nitrous stall so my powerband is 5300-6200. However, my engine just stays at 6000 once I launch and slips the whole way down and climbs up to 6200 and then I shift---good converter keeps the engine in powerband.

Good Luck

Matt