89formula350b2l

iTrader: (11)

I've looking around to see what i can do to defiantley get me in the 11.5X-11.7X range this year when the season starts again. My previous best was 12.89 @ 107 with a 2500 stall and 323 rear end. Well, I am getting a custom 3600 stall made and also upgrading the rear end with Motive 373's. I am thinking I will be in the 12.00-12.2x range maybe after upgrading those two.
So instead of doing the easy/cheap route of nitrous, I am wanting to keep it naturally aspirated. So i looked into a lil more cam and came up with this Lunati 54756.

• Duration @.050 IN/EX: 232/242
• Gross Valve Lift IN/EX: .510"/.525"
• Lobe Sep Angle / Intake Ctr Line: 110/106
• Valve Lash IN/EX: Hyd/Hyd
• RPM Range: 2000-6250

Would it be worth the cost of getting the cam and getting a re tune and upgrading the springs (or swapping back to 1.5 rockers)?

I also thought about the xfi280, but i dont know the specs on it?

1989GTATransAm

iTrader: (3)

Your heads will like higher lift. With EFI the XFI280 cam will be more friendly.

The XFI is 230/236 @ .050 and 280/288 advertised. RPM range is 2000 to 6000. LSA is 113. Lift .576/.570. ICL is probably 109. Again this cam will be easier to tune with EFI.

customblackbird

iTrader: (15)

im got the XFI280 for my 383 HSR, with patriot 195cc heads, the cam is a good cam and should give me 500hp and be able to tune with the EFI rather nicely.

the specs above are correct, the lift #'s are with 1.6rr.

Orr89RocZ

iTrader: (20)

becareful with xfi grinds...they are hard to control after 6000rpms. you WILL need solid spring pressure and more than likely its gonna be imperative that you run a beehive spring and titanium retainers. Lightweight is the key. I'd even run the 1.44" diameter big block beehive with 150-160lbs on the seat. open pressure in the higher 300's.

if you can control it, it will be fine. should make good power on the 383.

that lunati cam sounds like the GM847 cam but with less lift. should run good. else check out the comp cams 288hr which is 236/242. also a good cam.

you should be into the 11's with one of those grinds. just be sure to control valve float. a 236 duration cam or near that will want to rev to 6300-6500rpms.

customblackbird

iTrader: (15)

i had my springs upgraded on my patriots to dual spring, lightweight retainers, lift good for .670 hydraulic roller cam, im not sure the size of the springs or the seat pressure but i got the upgrade for my heads, i can tell u they are fat lil ***** lol. and im runnin 1.6full roller extruded rockers for less weight, i would like the Compcams chrome moly ones tho

89formula350b2l

iTrader: (11)

how much more power do you get from going 1.5 to 1.6 anyways?

customblackbird

iTrader: (15)

i kno on a stock 350tpi 1.6rr will give u 15hp.

the XFI280 or all the XFI idk becasue they rate the lift numbers with 1.6rr, so if u go to 1.5rr u will lose a good amount of lift of the cam and hurt flow. .567/.571 will be more like .537/.541

HiTech5

iTrader: (4)

The cam you list has too much exhaust duration over the intake. Also with that much duration and a 110 lsa, the idle and part throttle will be hard to tune due to the low vacuum pressure.

I ran 11.6@118 with my 383 including cats and street tires. I recommend a single pattern cam with your AFR heads.

236/236 @ .050 on a 112 lsa installed at 109 degrees. This cam would make power in the 3000-6500 range.

www.geocities.com/dzperf

Orr89RocZ

iTrader: (20)

alot of LT1 guys with ported LT1 castings that would put AFR flow numbers to shame have run large split pattern cams like cc306 and GM847 and put down very strong numbers. However i do think it would be best to keep split alittle tighter, around 6 degrees or so. Most custom grinds have some split in duration

HiTech5

iTrader: (4)

Orr - I've run both split and single pattern on heads with very high intake/exhaust ratios. I found that the single pattern really woke up the midrange of the motor without seeming to sacrifice top end. The split pattern tends to push the peak power to a higher rpm.

Orr89RocZ

iTrader: (20)

yeah thats what i've been seeing and why i am not running a CC306 grind

Chris Etemadi

Definitely need more lift to take advantage of those good heads. With a good I/E ratio AFRs have you shouldn't need that much split in duration. I was recommend a 234/238 .582/.590 on a 112 LSA by cam motion. I tried a few other places for recommendations, and they were all in that area.

89formula350b2l

iTrader: (11)

check this out

https://www.thirdgen.org/forums/tech...o-results.html

Orr89RocZ

iTrader: (20)

the big cams in that test that made 500 crank hp didnt rev as high as i expected. that could be due to valve float problems cuz a 240 degree cam should pull over 6000 in those 383's.

A good 500 hp cam would be something in the mid 230's intake duration with 4-6 degrees split and on a tighter 108-109 LSA. overlap will be in the low 70's which aint all that bad for such a big cam.

89formula350b2l

iTrader: (11)

right here

customblackbird

iTrader: (15)

so then my cams good! yay

89formula350b2l

iTrader: (11)

alright im gonna do the head LT into the single 3" Magnaflow exhaust I have on now and connect it with the Flowmaster y pipe collector. And maybe if I get antsy Ill do true duals. Until then, Longtubes, xr288 cam and maybe the true duals

Orr89RocZ

iTrader: (20)

that combo will rip man! get it tuned well and it will RIP!!

89formula350b2l

iTrader: (11)

Oh yes of course....I hope Jamy is up to the challenge. BTW I decided not to do the Commander 950. Jamy charges less than HALF the cost of the Commander 950 and since this will be the last change I do to the car (HAHAHAHA everybody says that), then the commander 950 would be a waste.
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I hope you dont mean Rest in Pieces like my car has been doing

Orr89RocZ

iTrader: (20)

yeah there is no reason the stock 89 MAF sensor setup shouldnt handle that combo. problem is tho i think fuel maxes out at 6400 with that ecm, and that cam will probly peak in the 6200-6400 range on a 383. so go over that with Jamy and see what he says. else convert to SD

89formula350b2l

iTrader: (11)

Already did when car was rebuilt with 383 kit

Orr89RocZ

iTrader: (20)

oh well your set!! good deal man cant wait to see it done

89formula350b2l

iTrader: (11)

Yeah well first thing is first, gotta get the performabuilt level 2 transmission and 373's in and get new times with those. If i come away from the track with a 11.99 slip, I'm sure I will have 11.5's in the bag with the xr288.