JASON99FRC

OK I just upgraded my LS2 427 from LS6 / Fast 90 top end to LS7 CNC HEADS, PORTED LS7 INTAKE, BIG CAM 251/267 .660 and it made great power on the first pull (564 RWHP) but the KPA reading was dropping to 95. Removed the green filter from the Vararam and stuck the fan right @ the air scoops and power jumped to 570 and KPA only dropped to 97. I also run twin QTP cutuots which were only open to ~ 25%. I will re-dyno tomorrow to see if the exhaust restriction was causing any of the problem.
but If I add a 100mm MAF must I ditch the Vararam VRB2 and buy an air intake system specific for a 100mm MAF?

Hopefully someone here has been through this.

RogerT

Please! Tell us more about the 100mm MAF. Application? Source?
Can it be used on other LS engines? Thanks.

Roger T : )

JASON99FRC

Roger,
There are ~ 5 different mfg's of these large mafs - Texas speed, Ligenfelter, SNL performance, Abaco, ???
Only needed if your maxing out your current MAF. Minimum 525 RWHP

ArKay99

Jason, I'm using a PowerMax 100mm MAF with a VaraRam 2B with Green filter. I also got in the mouth section of the VaraRam where it couples to the scoops with a razor knife and cut out some of the foam coupling stuff. I think it helped a bit. I'm also using a Haltech airbridge because it mates up well with the MAF as I have the MAF up at the 90mm throttle body.

JASON99FRC

ArKay99,
Appreciate the info

WKMCD

My 403/L92 build is pulling Kpa's back to 92.

I changed things out a little a week ago. I got a PowrMAF 100mm that I'll put on when the FAST 102 for the heads comes out hopefully in April.

It should breat a little better now.

gojo

Here's my 100mm setup.

BrianAgar

I am so glad I found this thread. I just purchased a Vararam VRB2 system and I was wondering if I needed to upgrade my stock MAF. I will be adding Flowmaster (or Magaflow) system with long tube headers. Should I upgrade my MAF to achieve highest performance or wait for my future engine rebuild? As soon as my LS1 dies, I will be upgrading the entire engine (Heads, Cam, fuel rails, injectors, etc.), but for now what do the Senior Corvette Techies recommend?

HardcoreABN

my MAF suggestion: Spectre 4" tube with GM card style MAF bung already welded on, then add a LS7 MAF. Total cost is like $50-$60.

BrianAgar

If I understand correctly, you're suggesting I add something like the tube in the attached photo? I assume it would be installed behind the Vararam system before the new C7 (100mm) MAF, which is attached to the manifold? Is this what you have shown in your photo?

HardcoreABN

You would not need 2 different MAF sensors. What I have is very similar, but with a lot better welds. I am mounting my MAF at the throttle body. It WILL need a tune though, as the MAF tables for the LS7 MAF are very different than any C5 MAF.

BrianAgar

Thank you Hardcore. Great info.

HardcoreABN

People are paying $100-$200+ for a MAF that they can put together for around $50 new that is just as well built and far easier to maintain. When I get mine back together I will post up some pics.

C5 Pete

$50??? I don't see how you can do it for that cheap.

I've got this available if someone's looking.

http://forums.corvetteforum.com/c5-p...-for-sale.html

BrianAgar

After adding the intake and your suggestions, should I install a cooler thermostat?

HardcoreABN

Housing = Spectre 9705 $17.95 from Amazon
LS7 MAF = GM 15865791 $45.00 Ebay.

So about $63. My bad.

BrianAgar

Talk about making it easy; thanks for posting the link.

HardcoreABN

Here it is with the MAF in it

BrianAgar

I just bought one and I am looking for the LS7 MAF. Thanks for the picture. What do you think about the Thermostat? Should I go cooler?

HardcoreABN

Any tuner worth anything can put a LS7 MAF table in it during a tune, so it really doesn't get any easier than that.