Chris Edwards

Ok that makes sense, I hadn't thought of the ridges being from the factory cnc. I guess that would mean that the intake ports weren't touched?

XLR8-R

Most significant flow gains will come from the short turn radius and bowl area of the ports(which is what it looks like he did). Opening up the part of the port in the area still showing the cnc marks would increase port volume and possibly hurt velocity. What I see looks good, I am curious to the flow numbers. Please post numbers when you get them, but they may not mean much unless whoever flows them has also flowed some stock LS7 heads(to compare them with)...

Chris Edwards

Ok guys flow numbers are back.

Tested on a Superflow 600, 4.155" bore

Lift Intake Exhaust
.200" 163 118
.300" 244 174
.400" 309 218
.500" 353 237
.600" 378 248
.700" 364 254
.750" 364 261

There are a bunch of different unported LS7 casting flow figures floating around so I won't bother posting, but here are AHP's advertised numbers for their heads per this thread:

Lift Intake Exhaust
.200" 171.1 121.2
.300" 245.7 170.6
.400" 312.8 208.3
.500" 351.0 234.0
.600 374.1 242.8
.700" 390.1 254.0

Since these figures did not come from the same flow bench on the same day, I would say they are pretty damn close. I actually did not have the flowtests done to put AHP's work in question, I just didn't get a flowsheet in the box like I did with my TEA's so I was curious. Then today I stumbled upon that thread above which corroborates the numbers.

bada

I know a tuner, that uses a lot of BTR cams. And he has tuned numerous, C6 ZO6s. And he told me, that from the BTR stage 2, to the BTR stage 4 cam. He usually only sees, about 15 RWHP. From the 2 to the 4. And maybe 8 to 10 RWHP from the 2 to the 3. And he preferred, the stage 2 for the all-round drivability. And you are only giving up, maybe 15HP at the top end. Down low all three cams, had close to the same HP with the stage 2, making more low end torque.

fueledpassion

While I sort of agree, if we're talking about a street car that utilizes power under the curve rather than the 4-7K rpms, it matters to use a dyno to tell a story.

That said, I'd say u need a really awesome aftermarket head + medium cam + lots of compression (at least 12:1). E85 would make this even more attainable. In all honesty, I'd just do LSX and build a 502 which would easily get to that number.

American Heritage

Good thread with some good info.

We do not currently own a dyno. We used to rent time at a local dyno but that fell through about a year ago. Since then we have only been doing wideband 02 street tunes.
We are in the process of acquiring a dyno. Any dyno numbers you would have seen would have come from an independent source and either posted by the customer or provided to us to post.

The independent flow bench testing results you posted seem to be right in line with our test results. As you mentioned in your post different flow bench's will test different (same with dyno's). Also atmospheric conditions (temp, humidity, ect...) will have a bearing on results.

We do 100% hand porting. We do not run any sort of CNC program.
We have two main versions of our ported heads. One is a street/strip port and the other is a full race port. On our street/strip heads we do not touch the intake runners at all (we do short turn, long turn, boss, bowl and throat work but no intake runner work). We have found that just removing the factory CNC lines on the intake port greatly reduces velocity and lower end performance suffers as a result. This is why on our street/strip heads we dont touch the intake runners. On a street/strip head you want a high velocity intake runner that will give you plenty of down low power.
On our full race ports we completely remove the intake runner CNC lines. This helps produce a much larger flow number and more power at peak RPM's but would not be suitable or recommended for street use since the loss of intake runner velocity would equate to a slugish or doggy feeling down low.

I am sorry we did not include a flow sheet with your heads. We recently switched over from our old portflow analyzer software to the newest version of portflow analyzer software. During the switch over our computer generated end of our flow bench was down and we had to read the manometers and manually calculate the numbers. Our Portflow analyzer software is now back online so we can produce a printable flow sheet.

I am glad you had our heads independently tested. We have nothing to hide and are more than happy to have our work on public display, we are very proud of the power our cylinder heads produce.

If you ever have any questions please dont hesitate to give us a call
310-326-2399
or shoot us an email
HP@americanheritageperformance.com
http://www.americanheritageperformance.com/

Your ported FAST 102 will be back in the mail to you later this week.

Thank you again for your business.

0Cunningham Motorsports

ran into this thread. in a c5 (weight being the factor) all this motor needs is a 231 duration (intake) cam, something similar to our stage 2 or BTR's stage two cam. if it was my car id run a MSD intake manifold and a LS2/7 silver blade 90 mm tb. the 102 will gain minimal power (at the very topend if any) and if its a ls3 ETC motored NW102 (most are) introduces a bunch idle characteristic issues utilizing the OEM c5 computer. Its tunable , but i am going to hate you LMAO (joking). it wont make 600 wheel on my dyno but it will make a solid 550 rwhp with great average hp and tq. here is the link to a 2014 z28 that has our stage 2 cam , wcch stage 2 heads and a MSD intake, shows you the before and after comparo with the stock intake. https://www.facebook.com/permalink.p...39721579418404

Chris Edwards

I appreciate the post Ryne, especially about the NW t/b. I will reuse my LS2 t/b which has no idle issues at all. After all the car spends way more time at idle than it does at wot so why sacrifice sanity for ~5 rwhp. And the smaller cam will be used thanks for that tip as well.

I wonder if the MSD intake has any more issues with the C5 firewall than the Fast? I already have a port matched Fast 102 so I will stick with that for now. Call me crazy but I prefer the look of the Fast.

Are those aftermarket wheels on that Z28? I wonder if those and the 3.90 rear gear are skewing numbers by 10/10 or so? Either way I will be satisfied with 560/520 on 91.

fueledpassion

560/520 would pull harder down low than the peakier setups anyways. When it comes to street racing and braggin rights, I'd rather the loftier cammed Z's be playing catch up with me than to be the guy that has to wind up my motor to reel it in.

One thing u could do is put a big cam in it, run high compression, screw the port n polish and other fancy upgrades and get 3.90's out back. It'd feel like a torque monster even with only 500rwtq.

Chris Edwards

Have done similar on previous builds. Broad torque curve + low freeway revs =

0Cunningham Motorsports

stock wheels on that z28. most of the dyno difference would be in the air intake, as the 90 degree bend in the intake tract isnt great for power. the c5/c6 straight over the radiator design is superior in this regard.

Vito.A

If you are interested in a broad torque curve, take a look at the Katech Torquer 110 +4 camshaft. It is the torque king, over 400 ft lbs at 2000rpm!

Chris Edwards

Ryne I planned to use the Halltech CAI with the LS7 card style MAF. You recommended the C5 MAF for my LS2 and from a tuning standpoint it would make sense you would prefer that I reuse it on the LS7 motor. Any objections to running the Halltech cai / LS7 maf? I feel like I'm giving up 5rwhp here, 5rwhp there and they're going to add up to leaving some serious power on the table.

BillY2KFRC

Just to back up info Ryne provided, that is solid advice. Doug from ECS said the same thing to me when I wanted to do the NW 102 on my car. Not worth the idle/livability issues for 5hp on a C5, especially since I daily drive my car on nice days and sit in plenty of stop and go traffic, I'd want to kill myself, lol.

As for the FAST 102 vs. MSD, I've been watching this recently. I've seen a couple of posts where the MSD out performs the FAST (even ported) by ~15rwhp when swapped back-to-back. That's a pretty serious difference. And one magazine just gained 30rwhp over an LS7 intake on a cam-only C6Z. Nothing to sneeze at, intake sounds legit, but two concerns:

1. Will it fit a C5? Apparently it will with a little work. I have the 3/8" shorter Hinson motor mounts (which I HIGHLY recommend, no negative NVH like the solid Pfadt mounts which suck terribly on the street). See this post: https://www.corvetteforum.com/forums...ce-intake.html

2. I recently had my FAST 102 custom painted which wasn't cheap and looks very pretty now. So I hate to give it up, lol. But for 15rwhp, might be worth it. Not sure yet.

JoesC5

I know it's not the answer you are looking for, but, if it were me, I would take the stock LS7 block you have, put on a set of PRC265 heads(not milled) with a set of long tube headers, keep the stock cam and then just put a E-Force on top at 5.5 psi boost on the stock 11:1 CR.

You will have great low end torque and your 600rwhp and the car will drive absolutely great around town and will get great gas mileage.