badgta

iTrader: (4)

just read a reply at ls1 tech were a guy said he ran the xfi 292 on his stock shortblock which was dyno tuned, he made 385rwhp, but he said he ordered an ai cam with a mail order tune and ran the same at the track, im going to see if he had the dyno sheets to compare to crackys and stuff.

think that custom xfi cam is the way huh?

Orr89RocZ

iTrader: (20)

Anything over 230 degrees is starting to get big for a stock shortblock or even a built 355. I like the smaller duration but tight lsa cams like ai's 226 234 cam. Custom 224 230 xfi on a 109 110 lsa would be interesting. Should peak in the 6200 range.

Any of the xfi lobes really need strong springs tho to see the rpms the cams are capable of. I would run 160 lbs on the seat

VincentZ28

iTrader: (2)

From what I've seen from the Dyno, a 268xfi peaks at 5800 and holds it to 6100. My 280xfi peak at 5950 and holes to 6200. So my guess the 292xfi should peak at 6200 and hold it to 6500. So to me Comp Cams are right on the money with their cams.

badgta

iTrader: (4)

well man i have been searching a load of sites for people who have that cam on a 350, everyone says oh no way too big, the 7000rpm deal comes in, and no one can back it up with a dyno sheet...

i was thinking about my buddie bluegrassz whos cam is a custom xe-282-hr12 cam, he is at 12.01 with factory suspension, a few little tweaks and he's in the 11 sec range.

im getting to the point, if i could find a cam that idles like a xfi 292 and can make 400whp in the 355 i am going to build, i could careless about the specs, as long as i could shift at 6500 where i want.

i am getting to the point to where i think it's an impossible goal, might just send it back to comp and trade in for the custom xfi cam i was thinking or a xe-288-hr10 one.

then again i went to the ai site and was impressed with some of the numbers a few guys had with factory bottomend lt1's, 430rwhp really peaked my interest.

RedGut86

Ok, I've gotta ask you guys. You talk about putting these cams in that make peak HP at 6500 RPM, right. But to maximize accelerative force, that means you should really be shifting around 7000-7200 RPM (since even past the power peak you'll have more torque multiplication occurring due to the taller gear. 1st > 2nd > 3rd etc)

So badgta, you say you want to shift at 6500 RPM, then I wouldn't think you would want the 292xfi cam. Let's say it makes peak power at 6800 RPM. You are gonna wanna shift WAY beyond 6500 and if you are shifting at 6500 you are loosing all of that power.

To shift at 6500 RPM you probably want to make peak power at 5800-6000 RPM or so. Then you can use the greatest torque under the curve for acceleration rather than accelerating to the peak and shifting there.

This of course can vary based on your transmission gear ratios but I'm just curious how you are planning on things. Maybe I just do things in a crazy way...

badgta

iTrader: (4)

well the car is setup for 1/8 mile, heres the specs

350 or 355 4 bolt 1pc seal block
4340 eagle crank
4340 eagle h beam rods
probe p2256 2v relief pistons
pro products or equlalient sfi balancer 6"
kevco racing oil pan
melling m55a oil pump with kevco pickup
arp oil pump shaft rod
arp main bolts
cloyes true double roller timing chain with -2* or +2* adjustibility
trickflow 1pc pushrods
comp pro magnum roller rockers
procomp tall centerbolt valve covers
afr eliminator 1038 195cc heads out of the box
gm factory roller lifters
stealthram intake gasket matched to a 1205 gasket, cleaned up basically
bbk 58mm tb
ford racing 30lb inectors
granatelli walbro 255lph pump
will be a tpi 7730 speed density setup
hedman cheap lontubes until i get the supercharger or turbo
true duals using the drews crossmember, h pipe with the small flowmaster race mufflers

t56 transmission
moser 9" with strage center section 31 spline moser axles
4.56 yukon gears
detroit trutrac diff
lakewood lower control arms
lakewood adj panhard bar
eibach sportline springs
new shocks struts all around
hotchkis subframe connectors

summit draglite wheels skinnes up front
15x8 rears with a 10" mickey thompson et street tire 26.1 diamater

mainly a 90% street vehicle cruise machine, 2 time a year trip to the track,
i want 400whp so bad i can taste it, but i am thinking it's just not a possibility, atleast
with the rpm limit of the valvesprings, i just hate to take apart brand new afrs out of the box when i might be able to find a cam that can produce what i am looking for, afr says the spring in the 1038s can handle 600 lift, but i will be running 1.5 rockers, around 550 lift max.

any other questions let me know. any help is appreciated, orr has helped me understand alot, but i would love to find some more dyno results to look at, time slips too.

thanks1

adam

Orr89RocZ

iTrader: (20)

i just noticed the 1038 heads are listed as 75cc chambers. Is this correct? I think that is going to make your goal even harder to achieve because compression will be very very low with those heads.

badgta

iTrader: (4)

correct, puts me at 9.2:1 i believe with the .015" felpro gasket, wanted it in that range for the future boost

http://cgi.ebay.com/ebaymotors/Chevy...item2c5332de71

i used this calculator here : http://www.rbracing-rsr.com/compstaticcalc.html

bore : 4
stroke : 3.48
gasket thickness: .015
deck height : .025
piston volume : 4
chamber cc : 75

Orr89RocZ

iTrader: (20)

i'd be nervous about the .015" gaskets, especially for boost. I dont think you'll see 400whp on 9.2 to 1 comp. You would need to spin it up for sure. Build for boost or build for n/a power, its hard to make that much power on low compression motor built for boost unless its larger cubic inches.

badgta

iTrader: (4)

well i was looking into the turbo deal, actually looking at yours to be exact, surley a 9psi engine even with 9.2:1 can make 500whp on boost? thats the ultimate goal, 10.5x's on 93, what ya think?

i mean, i can always have the block decked, and say run a felpro 1003 or equvilant? thats why it's crucial for me to discuss everything, and know exactly what i need, measure twice cut once deal, i always like the bbs single turbo headers, might get their kit, if i still can.

Orr89RocZ

iTrader: (20)

You can start a new thread on it but yeah, 500 on boost is nothing Should easily do that. I just like a thicker head gasket since you need a strong seal since chamber pressures get high under boost.

badgta

iTrader: (4)

thats kind of why i wanted the xfi line like the guy has here in his dyno, the 113* lsa would be more inline with boost, rather than say the xe-288-10 with a 110 lsa. but then again your running a 109* lsa with your setup correct?

could or would the xe-288-hr10 be a better choice and reach the ultimate 500whp with the turbo on down the road?

Orr89RocZ

iTrader: (20)

112 on the turbo, single pattern cam. 383 had the big split tight 109 lsa cam. If you go turbo i'd go smaller on the cam with a slightly wider LSA. 112-113 is ok

RedGut86

If you are really going to put a turbo on it. Don't sweat the 400rwhp goal NA. Set your blown power goal and build for that. Otherwise you'll just be buying parts x2 when you put the turbo on.

Back on topic.

Vincent, did you make it out to the track? How did it run? Also, do you have the dyno sheets in numbers? (100 or 500 RPM increments or something like that.)

whitez406

iTrader: (5)

im gonna pull this from the dead but regarding someones curiousity to xfi292 combo. my buddy and i built a 355 for his 94z28 and combo was stock crank and rods mahle pistons balanced rotating assembly 12.1 (yes 12.1) xfi 292 cam fully ported stock heads ferrea 2.02/1.60 valves ported lt4 intake and twin 58mm tb with electric pump and tuned the car made 426whp and just shy of 450wtq the car was a blast to drive. 6 speed thru 12 bolt

Dyno Don

iTrader: (7)

Just a little update to this thread....
Several of us have exceded the 400 HP to the rear wheels now and Allen's car exceded the 11.6 ET at the track.

Orr89RocZ

iTrader: (20)

That torque number is insane for a LT intake car...almost hard to believe thats how good that number is. Most LT1's i've ever seen that made over 400whp do not make more torque than HP.

What was the hp peak rpm?

88BlackZ-51

iTrader: (2)

450rwtq from a 355? wasnt sure if that was a type'o or not......