Ls3 NA Build For My Focus
03-10-2018, 11:07 PM
#1
Ls3 NA Build For My Focus So I put my new LS3 focus on the dyno today and i am a little disappointed in my numbers.
I believe the lack of power might be from the cam shaft. I am thinking of ordering another cam on monday
this is my current set up.
ls3 block
JE +10 dome pistons
Eagle H Beams
Trick Flow 255 heads
Comp 297LRR Cam
Sheet Metal Intake
2 inch Headers
The low down low torque numbers are from the high stall
Also this dyno run i rolled into the throttle slowly bc of tire spin on the dyno but i started the sample too soon.
Any insight on the camshaft would be helpfull
https://ls1tech.com/forums/conversio...ord-focus.html
I believe the lack of power might be from the cam shaft. I am thinking of ordering another cam on monday
this is my current set up.
ls3 block
JE +10 dome pistons
Eagle H Beams
Trick Flow 255 heads
Comp 297LRR Cam
Sheet Metal Intake
2 inch Headers
The low down low torque numbers are from the high stall
Also this dyno run i rolled into the throttle slowly bc of tire spin on the dyno but i started the sample too soon.
Any insight on the camshaft would be helpfull
https://ls1tech.com/forums/conversio...ord-focus.html
Last edited by topspeed1; 03-11-2018 at 10:32 AM.
03-11-2018, 03:55 AM
#2
TECH Veteran
That cam is way too big for a stock cube motor. A cam with over 240 duration does best in stroker applications that' over 400 cubic inches.
03-11-2018, 08:30 AM
#3
As you can see in the dyno chart my power is already falling off at 7500 rpms
03-11-2018, 09:39 AM
#4
If it were mine, revving over 7500 rpm, I wouldn't be messing around with a HR valvetrain, short travel or not. That dyno curve says to me your valvetrain is out of control.
What TC are you running? I've run a 4400 8" and still had very strong torque numbers down around 4000 rpm. Just my opinion, but your low torque numbers are probably due equally to both the cam size and high stall effect.
What TC are you running? I've run a 4400 8" and still had very strong torque numbers down around 4000 rpm. Just my opinion, but your low torque numbers are probably due equally to both the cam size and high stall effect.
03-11-2018, 10:31 AM
#5
If it were mine, revving over 7500 rpm, I wouldn't be messing around with a HR valvetrain, short travel or not. That dyno curve says to me your valvetrain is out of control.
What TC are you running? I've run a 4400 8" and still had very strong torque numbers down around 4000 rpm. Just my opinion, but your low torque numbers are probably due equally to both the cam size and high stall effect.
What TC are you running? I've run a 4400 8" and still had very strong torque numbers down around 4000 rpm. Just my opinion, but your low torque numbers are probably due equally to both the cam size and high stall effect.
was specifically makes you say my valve train is out of control? just curious
thanks for the help
03-12-2018, 12:10 AM
#7
The high stall converter is an aggravating factor, but it's not the primary cause. You'd have the same pathetic torque numbers even if you had a stock converter.
Otherwise.....550 HP to the wheels ain't nothing to sneeze at for a stock displacement LS3.....but you pay for it with the lack of torque.
KW
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03-12-2018, 02:44 AM
#8
Man, people don't read.
Did you do any runs out to 8k to see how hard it drops off? Are the heads box stock? Heavy valves? Also, use sae correction factor and set the smoothing to 5. The numbers might be lower but they'll be legit and the run will look better. 600 to the tire with a stock cube deal through an auto seems like an awful tall order. Seems to run pretty hard to me.
Did you do any runs out to 8k to see how hard it drops off? Are the heads box stock? Heavy valves? Also, use sae correction factor and set the smoothing to 5. The numbers might be lower but they'll be legit and the run will look better. 600 to the tire with a stock cube deal through an auto seems like an awful tall order. Seems to run pretty hard to me.
03-12-2018, 08:34 AM
#11
The low RPM torque numbers is because you have too much cam for the displacement and the sheet-metal that you're running. And if your static compression ratio is below 12:1.....then you can add that as an issue, as well.
The high stall converter is an aggravating factor, but it's not the primary cause. You'd have the same pathetic torque numbers even if you had a stock converter.
Otherwise.....550 HP to the wheels ain't nothing to sneeze at for a stock displacement LS3.....but you pay for it with the lack of torque.
KW
The high stall converter is an aggravating factor, but it's not the primary cause. You'd have the same pathetic torque numbers even if you had a stock converter.
Otherwise.....550 HP to the wheels ain't nothing to sneeze at for a stock displacement LS3.....but you pay for it with the lack of torque.
KW
Compression Ratio is 12.7:1
Running on e85
03-12-2018, 08:38 AM
#12
Man, people don't read.
Did you do any runs out to 8k to see how hard it drops off? Are the heads box stock? Heavy valves? Also, use sae correction factor and set the smoothing to 5. The numbers might be lower but they'll be legit and the run will look better. 600 to the tire with a stock cube deal through an auto seems like an awful tall order. Seems to run pretty hard to me.
Did you do any runs out to 8k to see how hard it drops off? Are the heads box stock? Heavy valves? Also, use sae correction factor and set the smoothing to 5. The numbers might be lower but they'll be legit and the run will look better. 600 to the tire with a stock cube deal through an auto seems like an awful tall order. Seems to run pretty hard to me.
The heads are trick flow 255 with TEA hollow intake valves.
I had hoped with so much duration and a sheet metal intake power would pull strong until 8000+
03-12-2018, 08:42 AM
#13
Well, it sounds like you have everything under control then.
Just bolt on some slicks for your next dyno pull.
.."I had hoped with so much duration and a sheet metal intake power would pull strong until 8000+"
It will, IF your valvetrain can take it
Just bolt on some slicks for your next dyno pull.
.."I had hoped with so much duration and a sheet metal intake power would pull strong until 8000+"
It will, IF your valvetrain can take it
03-12-2018, 09:11 AM
#16
Cam isn't "too big" if you are looking for power north of 7500RPM. Looks like valvetrain issues. Has a hard time getting past 6500rpm, hangs up there for a bit, then barely climbs from there to 7500. It takes a lot more than a big cam and a nice intake to get to 8k RPMs.
What are your complete valvetrain specs? 7500+ is a lot of RPM for any HR cam. That combo wants a solid roller with proper valvetrain to be honest, but if you can stabilize the valvetrain you will make more power up to 7500. I would guess you have at least 25rwhp left in that valvetrain...which still won't be your 600rwhp through a stalled auto...that seems like a very lofty goal for a hydraulic roller stock cube LS3, even with killer parts. 575rwhp NA through a big stall is very impressive though...
FWIW, my 383 is roughly the same cubes as an LS3 and was spec'd a larger cam than that - but it is a solid roller cam along with beasts of a valvespring, quality shaftmounts, and massive pushrods. Not the stuff you usually see on street cars, since the spring pressures you need to keep an SR cam that aggressive happy make routine checkups important. It seems you are trying to get away from that with an HR, but you can't have your cake and eat it too...sacrifices will have to be made if you want an NA 7500-8000 rpm 600rwhp stalled auto.
What are your complete valvetrain specs? 7500+ is a lot of RPM for any HR cam. That combo wants a solid roller with proper valvetrain to be honest, but if you can stabilize the valvetrain you will make more power up to 7500. I would guess you have at least 25rwhp left in that valvetrain...which still won't be your 600rwhp through a stalled auto...that seems like a very lofty goal for a hydraulic roller stock cube LS3, even with killer parts. 575rwhp NA through a big stall is very impressive though...
FWIW, my 383 is roughly the same cubes as an LS3 and was spec'd a larger cam than that - but it is a solid roller cam along with beasts of a valvespring, quality shaftmounts, and massive pushrods. Not the stuff you usually see on street cars, since the spring pressures you need to keep an SR cam that aggressive happy make routine checkups important. It seems you are trying to get away from that with an HR, but you can't have your cake and eat it too...sacrifices will have to be made if you want an NA 7500-8000 rpm 600rwhp stalled auto.
Last edited by Puck; 03-12-2018 at 09:27 AM.
03-12-2018, 09:17 AM
#17
That dyno clearly points to valvetrain issues IMO. You have PLENTY of motor for that cam.
03-12-2018, 09:25 AM
#19
Everything about your combo screams solid roller. An HR can work with the right valvetrain specs, which we still haven't gotten from you, but no matter what an HR will leave power on the table at the RPM range your motor wants to be in.
That dyno clearly points to valvetrain issues IMO. You have PLENTY of motor for that cam.
That dyno clearly points to valvetrain issues IMO. You have PLENTY of motor for that cam.
3/8 pushrods
The dual valve springs that came with the trickflow heads
TEA hollow intake valves
Stock rockers with trunion upgrades