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I'm running a 246/258 .639" 113 degree bullet cam on my LSX 454 and made 744hp @ 6800rpm & 639tq at 5100 in the test cell. Brodix heads and Mast intake. No issue with idling and i'm using a Holley HP. I also using Hyd limited travel lifters,
Those ITB's in that test were too small if i remember rightly??
Here is a dyno sheet of my 419vs454, the 454 has a FAST 102 and mine has 55mm Kinsler ITBs on.
Those ITB's in that test were too small if i remember rightly??
Here is a dyno sheet of my 419vs454, the 454 has a FAST 102 and mine has 55mm Kinsler ITBs on.
I cannot make out anything from the graph. The colors are the same and which car is which?
There was something up with that test for sure. typically, on ITB, the midrange goes REALLY high in a 500-1000 rpm band where the runners and cam sort of work together perfectly, and then starts falling from there and carries well past peak.
I'm running a 246/258 .639" 113 degree bullet cam on my LSX 454 and made 744hp @ 6800rpm & 639tq at 5100 in the test cell. Brodix heads and Mast intake. No issue with idling and i'm using a Holley HP. I also using Hyd limited travel lifters,
That’s right around where I want to be for power and torque. You sir have one badass setup!
I’m thinking of somewhere in the 680+ wheel hp. 700 wheel is my main goal. But I would be happy with 680 - 690.
I wonder what I need to do to be able to get there.
…..Custom spec cams are a hit and miss based on my experience......
Custom cams are a hit when you spec the engine correctly and spec the cam to go with that!
I've seen a lot of talk about cam specs mut nothing regarding the following, for a start:
Compression Ratio
Valve Train (Rockers/Valves/Springs)
Head Specs (Intake/Exhaust flow and at what lift you hit peak flow)
Hot Rod Magazine Tested an ITB intake against other LS3-based intakes. The Speedmaster IR Downdraft, which is a $2k intake. I don't know the quality compared to Harrop or whatever. But there you go.
But, the Short Runner FAST made the same power and slightly less torque... Holley Hi-Ram beat it overall. While the Holley Sniper, Edelbrock Victor Jr. and Super Victor, and Edelbrock Crossram all were better in power and same in torque (with Crossram beating out even the long-runner FAST).
The new FAST XR/pTR made the most power and torque of anything. And the Edelbrock Pro-Flow XT was right there with it.
Point is, I just don't see this being a justifiable $4k or more upgrade. It is cool and may make tuning of a bigger cam easier. But if you use a newer PCM, tuning a big cam is much easier than the Gen III PCM with it's IAC garbage. But if you cut your cowl to fit the ITBs, you could run a Pro-Flow, Hi-Ram, a Super Victor, or the new FAST XR, and it would make more power. Especially with an LS7 head.
Dyno between a stock LS3 intake and the ITB...
These ITB's had a 2.00" (50.8mm) blade, no wonder they gave up on the top end...
That’s right around where I want to be for power and torque. You sir have one badass setup!
I’m thinking of somewhere in the 680+ wheel hp. 700 wheel is my main goal. But I would be happy with 680 - 690.
I wonder what I need to do to be able to get there.
I can send you the build sheet and the dyno numbers if you would like, wasn't cheap in the end but i'm happy.
The heads came from WCCH and i'm at 11.5:1 so I use pump gas and it was set at 28 degrees advanced on the last pull in the dyno. I didn't need to get the max out of it, i'm using it on the road course racing so getting full use out of the HP isn't viable until another corner comes up.....
That’s right around where I want to be for power and torque. You sir have one badass setup!
I’m thinking of somewhere in the 680+ wheel hp. 700 wheel is my main goal. But I would be happy with 680 - 690.
I wonder what I need to do to be able to get there.
FYI there is a guy who had Tony Mamo build him a 454 who has it up in the for sale section. IIRC he said 670hp at the wheels, asking $20K. There was a link kicking around in one of these big cube threads.
I have a 2008 Corvette Z06 with an LSX 454, RHS Pro Elite LS7 heads, ID1000 injectors, Fast 102 intake, Comp Shaft Mount Rockers, McLeod Dual RXT clutch.
Last time I got a custom spec cam I got a smaller than desired cam. 236/248 .634"/.634" 117+3 lsa. I went ahead, bought it and installed it. It runs great and strong especially after 4000 RPM till redline @7100. Idles great too. Not stock drivability but very minimal surge at low speeds.
I have plans to build a maxed out streetable NA setup.
What cam will gain me the most power for my setup?
I want a streetable car since all my races will be drag races from a roll to very high speeds.
I know and realize I wont have stock like idle nor drivability and I don’t care. I just want the most powerful streetable setup.
Custom spec cams are a hit and miss based on my experience. What do you guys recommend? Whether it be custom or off the shelf proven cams?
Cam will be a hydraulic roller cam not solid.
Your input is much appreciated.
My recommendation is a 248/262 114 LSA +3 camshaft for something driveable for your engine size or go one step further with a 252/266 112 LSA +3 with 35 degrees of overlap.
I have a 243 / 259 at .050 on a 114 (660 lift) in my 454 LS7 - it is very driveable with a stick in a Corvette with 3.42s. A heavier clutch helps with pooping around town. If you have an auto with a stall you got more options.
I have a 243 / 259 at .050 on a 114 (660 lift) in my 454 LS7 - it is very driveable with a stick in a Corvette with 3.42s. A heavier clutch helps with pooping around town. If you have an auto with a stall you got more options.
That's an ok spec for a 454 in a manual.
However if you had an auto the above spec would work better.
You would make more torque and hp and still have decent driveability
That's an ok spec for a 454 in a manual.
However if you had an auto the above spec would work better.
You would make more torque and hp and still have decent driveability
I agree the auto - has a little more leeway. Cam surging/bucking at sub 1,500 rpm while just diddling in traffic is not fun.
I agree the auto - has a little more leeway. Cam surging/bucking at sub 1,500 rpm while just diddling in traffic is not fun.
Agreed.
How cool would it be if somebody came up with a device that works like a stall converter on a manual?
If your engine was ever converted to an auto and was a weekender I would use the 252/266 112 LSA +3 and also utilise more lift to take advantage of that extra flow with the heads.
Not to highjack the thread but I do have a complete Harrop Hurricane ITB solution for the c6 z06. There also exists a thread on it here in the forum, but I’d have to dig up the link. Below is a pic of the current state...
I‘m actually gonna upgrade to an HPR 468 this winter along with a ZR1 transmission since mine couldn’t handle the torque anymore. I‘m also trying to figure out what cam size to go with for the big cubes and ITB. I have a custom grind 254/262 112 sitting in my room which was designed for the intake on a 427, but I do want to maintain drivability. Which btw, it is much better with an ITB, however you will still experience light surge since your MAP signal still has fluctuations on it which mess with your closed loop fueling. I am trying a mechanical „filter“ next week, to get rid of these fluctuations on the MAP sensor. Then it may drive like stock I hope. Currently I have a K501 cam, which is not ideal for this intake due to its long runners. You reach peak power around 6300 RPM and then it falls off relatively quickly. For a 454 or 468 with a 6500 RPM redline this may be ideal though.
looks badass... wonder if you'd be better off in open loop?
Thanks! Yea, I’ve considered open loop, but there are slight changes to fueling requirements with changing IAT and water temps etc. The IAT variations can be tuned out to an extent, but the rest is difficult. It would be awesome if one could set up open loop only for certain load situations. But this is whining about the last few percent.
01-21-2019, 07:29 AM
