Shorter Runners for FAST Intake!!!
That's basically where I am. Not for most guys. And as KW said, nobody wants to call it the limited-market product it really is. I WANT to make peak power 7K+ and I have more power than room for rubber so I don't mind the low-end loss. I still think it(102, mid runners) can work well on a high-winding 6.0 with a relatively stout cam but I may not find out for a while.
Well I'm fully committed to the ITB setup so I sold off my mid-length 102 to my buddy Steve. He'll get it on a lot quicker than I will. Here is his build thread so we put him in the hot seat. 
https://ls1tech.com/forums/cadillac-...s3-done-2.html
https://ls1tech.com/forums/cadillac-...s3-done-2.html
Ha, no pressure. Thanks Chris. I'll be getting things put back together in the next couple of weeks. However it's be 30 degrees every morning, so winter time is just about set in here in Ohio. I'll post the results of my build, but it might not be until late March or early April....
Idk....i would love to see them at least tested on a stout bolt on set up. Most guys don't turn their stuff hard enough but with the right stuff a bolt on ls3 will run to 7300. Same goes for my ls6....but that's kinda off topic.
Made some good progress this weekend getting my motor back together. Also got the fast 102 with the high hp mid length runners Mercier sold me. The intake is a bit taller than stock as I had about 1/2 to 3/4 clearance between the stock ls3 intake and my fuel regulators pressure gauge. The fast was touching. Had to move the regulator over a bit to clear.
Teching In
Joined: Oct 2005
Posts: 15
Likes: 0
From: Ontario, NY ,USA
Made some good progress this weekend getting my motor back together. Also got the fast 102 with the high hp mid length runners Mercier sold me. The intake is a bit taller than stock as I had about 1/2 to 3/4 clearance between the stock ls3 intake and my fuel regulators pressure gauge. The fast was touching. Had to move the regulator over a bit to clear.
Attachment 558010
Attachment 558011
Attachment 558009
Attachment 558010
Attachment 558011
Attachment 558009
I am installing them on my 416 LS3 that now has a BER ported LS3 intake producing 650 engine HP at 6500 RPM. I should have the intake in a week or so.
The High HP runners look longer in your photos then the ones I see in photos from FAST.
Last edited by C6RAPTOR; Nov 21, 2016 at 12:36 PM.
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Originally Posted by C6RAPTOR
Keep us up on your progress. I also ordered a LSXR with High HP runners from WCCH . WCCH will be port matching the runners to my WCCH stage 3 heads and deburring the runners. In that subject , what does the inside surfaces of the runners look like as received?
I am installing them on my 416 LS3 that now has a BER ported LS3 intake producing 650 engine HP at 6500 RPM. I should have the intake in a week or so.
The High HP runners look longer in your photos then the ones I see in photos from FAST.
I am installing them on my 416 LS3 that now has a BER ported LS3 intake producing 650 engine HP at 6500 RPM. I should have the intake in a week or so.
The High HP runners look longer in your photos then the ones I see in photos from FAST.
Teching In
Joined: Oct 2005
Posts: 15
Likes: 0
From: Ontario, NY ,USA
The inside of the runners did have some burs where the plastic was joined together. I removed them with a small flat screwdriver. I didn't want them eventually breaking off and going into the motor. Other than the seam in the middle they were very smooth on the inside.
Attachment 558112
Attachment 558112
Would you mind sharing the details on your build?
This will be going on my 418ls3 with gmpp cnc ported heads, 11.4:1 compression. I'll be running a BTR stroker cam. I plan to shoot for 7200rpm on the dyno. I've set my valve train up to be light weight, using Johnson 2110 lifters, PSI 1511ML springs and titanium retainers.
I had previously tried a CamMotion low lash solid roller cam and stock ls3 intake. The setup worked well, but the solid setup was more than I wanted to deal with long term. So I'll see how my new setup does with the new cam and new intake. Should be interesting..
I had previously tried a CamMotion low lash solid roller cam and stock ls3 intake. The setup worked well, but the solid setup was more than I wanted to deal with long term. So I'll see how my new setup does with the new cam and new intake. Should be interesting.
. 
Is 7600-8000 safe with a 4.00 stroke though? I figured the springs could handle more as they use them on the Copo at close to 9000rpm. Just not sure on the rpm ability of the stroker setup. Callie's crank and rods, arp rod bolts, arp main studs, JE forged pistons.
If you get to digging there are plent sbe guys goin to 7500. Including 1 sbe ls7 getting spun to 8k. So i would think a built bottom 4" stroke could handle atleast 7500 if it's done right.
Good point here. I routinely forget that the LS7 stock is the longer stroke. It *does* have Ti rods though.
4.100" stroke in my C5Z goes to 7500 almost every day. 3000 miles in just the last few months here.
I am looking forward to some dyno numbers on this. I would really like to see if it can make more average power over a 2500rpm area.
I am looking forward to some dyno numbers on this. I would really like to see if it can make more average power over a 2500rpm area.
