CANROC85

I just wanted to share my recent dyno results and maybe show the difference the new exhaust made.I had an SLP sysytem 1 3/4 header dual cat system, it was good enough to put 415 hrsp @5600 and 441 ftlbs @4200 to the wheels so was unsure how much more I could expect. It was peaking only at 5600 so I was hopeful the exhaust was holding the engine back.The new exhaust is a stainless works LT 1 3/4 with 2.5 collectors and 2.5 y pipe attached to the 4 in mufflex system ending in the Magna Flow race muffler.The results are I think impressive 463 hrsp @ 5900 and 464 ftlbs @ 4200. I still trying to figure out the posting of the dyno sheet.Dyno jet file not accepted file. The graphs will show the gains from 3000 all the way up.

antoine

That's dam good

LB9GTA

iTrader: (1)

I made 377rwhp with my 280xfi (flat tappet tho)

What brand of dyno?

What are you getting for et's?

Good work!

CANROC85

Dynojet the graph shows my before and after the exhaust work both done on the same Dyno.

CANROC85

Thanks

CANROC85

Last year did one trip to drag strip et was 12.54 some pretty poor launches and 115 mph. That was before I did the first dyno which the first run was 380 to the wheels so hopeful for some good mph this year but et will probably still stink.

paul_huryk

Very good numbers... Should pickup 4 or 5 mph next time you have it at the track.

Orr89RocZ

iTrader: (20)

Whats the engine combo? Thats the most i ever seen from a 280xfi. Most setups seem to crap out around 400-420whp and no more. And a 50 hp gain with just exhaust mods is incredible. I had a even bigger cam than the xfi with afr 195's and ported holley stealth ram and could only make 400whp but trapped 119 in hot august air in pa.

CANROC85

Thanks I hope to break into 120's.

CANROC85

Its a 385 afr 195 comps (1095), rpm airgap, prosystems carb, xfi 280, crowler roller rockers 1.6, eagle forged crank,mahle pistons, Thats about it with the new exhaust stainless works longtube 2.5 collector to 2.5 y to a 3 in then the mufflex 4 in ending in the magnaflow race muffler.
The best part is how drive able it is 15-16 inches of vacuum at 800 rpm and with the t56 it will give 30 imperial mpg on the highway.
Where you running an auto tranny?

Orr89RocZ

iTrader: (20)

I was running an auto 700r4 with converter locked on dyno. Very hot day and hot motor but i dont see much more to be gained. I honestly would never expect your combo to make that much power. Love to see track times. That thing is on par with my buddys old 406 solid roller car that trapped 127-128 with 6 spd, 460's whp

CANROC85

I figured that the 3 inch section must be causing some back pressure at that power level. 3 inches only flows 812 cfm 540hsp would be 1188 cfm (2.2 cfm/hsp) just not sure how much it would be.Car weighs in at about 3670 lbs so pretty sure mph likely to only be 123 ish.

CANROC85

I also wondered what you think about a custom cam similar to the xfi 280 but getting the lift up just over 600 maybe 610?

Orr89RocZ

iTrader: (20)

If you wanted more rpm, perhaps a ported manifold or a vic jr. A different LSA would likely work well too. The XFI lift is pretty good where its at, but .600 or so in the intake lobe will help give abit more rpm and power up top. It will hang on alittle longer but the intake is designed to peak around that 6000 rpm range.

Either way its making darn good power for the combo. Like I said, most i've seen posted anywhere with that duration/lift/lobe series. Job well done.

CANROC85

Orr I was wondering what you think of running 1.7 roller rockers as the gentleman suggested on speed talk ?

Orr89RocZ

iTrader: (20)

I think it would help if you can keep the valves in control. May need to shim the springs a touch for more pressure on the seat. I turned a 230 .603" lobe with 1.6 rockers to 7k rpm with 8019 springs shimmed a tad to i think 1.775-1.78" install height which gave 165-170lbs on seat. Its a good bit of pressure but it worked. That was with ls7 lifters

What lifters you using? If gm type may want to consider morel link bar stuff. Its build better to handle more spring pressure and made stronger out of a tool steel body. Supposively worth 10-20 hp on mosy aggressive high rpm stuff.

CANROC85

I have comp retro t bar lifters 853-16.
Might be worth a try.

CANROC85

Orr, Mike Jones specked a cam how do you think it would work?
Part# HR73389-74365-110
284/288 @.006"
234/240 @.050"
.389"/.365" Lobe Lift
110 LSA
My HP estimates are always on the low side, but I show 495hp, and 452ft/lbs
I asked him if that is flywheel or rearwheel horsepower but doesn't seem to want to respond. If another 30 hsp then worth the bother.It seems cam guys always want to keep things close to their shoulder. If rear wheel then not worried about price, anyway I trust your opinion thks John

rsmith085

iTrader: (1)

Quite impressive! I'm thinking about building a 350 with that cam or doing a 5.3/6.0. I love the LS stuff but then again I love the fact a sbc bolts right in. Might want to go up on the jetting, according to the dyno graph your running a bit lean.

Orr89RocZ

iTrader: (20)

Jones knows his cams and that one looks good. But is it worth 30 hp more? I dont know. I wouldnt think so but i also would never expect your combo to make what it did. That cam has a bunch more lift and abit more duration so its gonna pull alittle higher and get more power out of the heads. Just not sure how much but it should definately be an increase. To be honest i would have expected abit more duration out of a cam designed to make 500 whp. Also maybe 3" collectors and ported vic jr single plane could help. More rpm is more hp

TPI-Formula350-

I'm late in seeing this post, great numbers! What intake are you running? I have a very similar setup but I made 467HP/517TQ at the flywheel. I haven't had a chance to put it on a chassie dyno since I got it running decent, hopefully this Spring.

edit..see you posted it has a carb.

CANROC85

Thanks the intake is an rpm air gap.

IROCZ1989

iTrader: (1)

I made 428hp and 480ftlbs on my tahoes 383 with a single plane and a 268xfi cam. Those numbers are with vortec afr heads and 9.7-1 compression. I just switched to the stainless works headers on my 355 and I was equally impressed with canroc85s gains. One of the deciding factors of my decision to switch.

David 91RS/Z28

Long tubes are the way to go! Track times improved a half sec on my setup. I had swapped from the SLP Tri-Y to the Hooker LT's. Power improved in the whole rpm range! It was night and day!

David 91RS/Z28

Nice numbers too!

z 28 jari

iTrader: (1)

Just curious,how much do you improve(I have also tri-y's..)

David 91RS/Z28

I don't have any before or after dyno times, but as I mentioned above times dropped right at a half sec.

IROCZ1989

iTrader: (1)

Dave, I know yours is a 383, my camaros a 355. Im just trying to hit high 11s. This combo ran a low 12 without the long tubes with a 5 speed. Ive lightened up the car, aftermarket ecu, built 700 with vig 2800 stall. Epping NH is a fast track. Im very confident the car will break 11s on motor. After doing a ton of reserch, I finally bit the bullet on the stainless works units, from pics here and from sw recommendations the 3 inch collectors are a tight fit. Like I said the deciding factor was canroc85s dyno sheet, its even on Hawks website. Heard to many times about how the shorties are just as good, I think its unfounded only because at the time the only full length was super comps, and they fit like crap compared to the SW longtubes. Night and day difference in fit and quality. How much did you gain mph wise Dave? Same weight, gears, and tire size? Would like to see roundabout hp calculations. Take care.

bdiroc

sorry to bring this back up so late ,you said you had slp 1 3/4 headers and dual cat, but what was your cat back setup before the change?

I would think the catback had to be way to small and caused most of the loss not the front side of the exhaust