Does this sound about right for a 408?
Does this sound about right for a 408? I had my TA retuned recently at Modern Muscle In Oswego, IL. We did a speed density tune this time.
Ive got a pretty decent setup I think.
Ported FAST 90/90 FTP 104mm lid
TFS 235cc heads
Custom cam 246/254 .646 duration on 113 LSA
kooks 1 7/8" LT headers and kooks ORY, cutout
Built t56
strange 12 bolt w/ 4.10 gears
315 M/T dr's
I was hoping for atleast 530-540 or even 550. This was done on a very hot and humid 95 degree day and on a mustang dyno. The shop told me that 4.10 gears was an automatic 10-15 hp loss on the dyno as well. My cam should be making power to 7200rpms but they said my intake was flow enough air past 6500. I asked what intake would flow that much and they went into saying how I would to drop a small fortune on a custom sheet metal intake which i thought was kind of BS. They said no fast intake setup is going to flow that high.
So with all the variables does this sound like my car is making the power it should? What intake would work better with my setup? I was thinking maybe a vic jr?
Ive got a pretty decent setup I think.
Ported FAST 90/90 FTP 104mm lid
TFS 235cc heads
Custom cam 246/254 .646 duration on 113 LSA
kooks 1 7/8" LT headers and kooks ORY, cutout
Built t56
strange 12 bolt w/ 4.10 gears
315 M/T dr's
I was hoping for atleast 530-540 or even 550. This was done on a very hot and humid 95 degree day and on a mustang dyno. The shop told me that 4.10 gears was an automatic 10-15 hp loss on the dyno as well. My cam should be making power to 7200rpms but they said my intake was flow enough air past 6500. I asked what intake would flow that much and they went into saying how I would to drop a small fortune on a custom sheet metal intake which i thought was kind of BS. They said no fast intake setup is going to flow that high.
So with all the variables does this sound like my car is making the power it should? What intake would work better with my setup? I was thinking maybe a vic jr?
508 on a properly calibrated Mustang dyno is nothing to sneeze at... Congrats on an awesome build. Get it to the track at let the real numbers tell the tale... 
As far as the intake goes, I've seen many Fast 90's go well into the high 500's. I'd look at valvetrain stability first since it seems your graph starts to flatline around 5500. This is typically where valve float rears its ugly head in the LS1 world.
Shane
As far as the intake goes, I've seen many Fast 90's go well into the high 500's. I'd look at valvetrain stability first since it seems your graph starts to flatline around 5500. This is typically where valve float rears its ugly head in the LS1 world.
Shane
Last edited by XtraCajunSS; Aug 11, 2010 at 01:46 PM.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Maybe not worth the money IMO. A ported FAST 90 is still a decent piece. I would look into something different like a Victor setup...or sheet metal, or a cam that would peak in the 6500 range. Or be happy with and go to the track!!
What about the victor jr. intake? I was told by the shop that no FAST intake setup would flow enough air to hit 7200 rpms. Not to mention the FAST intakes are very expensive.
LS1TECH Sponsor
Joined: Sep 2004
Posts: 274
Likes: 0
From: Houston
i think those numbers are right where they are supposed to be for a car with a 12 bolt. you dont see very many 408's get too far passed that without dyno tricks :-).
I picked up quiet a bit up top going from Kooks 1 7/8 to 1/78 stepped to 2 inch with 3.5 collectors...but youll definetely get more swapping the 90/90 for a 102/102..
If you have any problem at all it would be valve float in my opinion... but i dont see nothing wrong with those numbers.
I picked up quiet a bit up top going from Kooks 1 7/8 to 1/78 stepped to 2 inch with 3.5 collectors...but youll definetely get more swapping the 90/90 for a 102/102..
If you have any problem at all it would be valve float in my opinion... but i dont see nothing wrong with those numbers.
12 Second Club
iTrader: (13)
Joined: Feb 2005
Posts: 1,575
Likes: 1
From: Gateway International Raceway
Last edited by ExceSSive; Aug 12, 2010 at 09:55 PM.
I say its very close.. I have a 408 with tfs 215s and ported 95, under drive, and moser 9 with 4.11 gears. dyno posted! Im only running a 12.009 at 3800ft alt(kills me in el paso). with 1.7 60ft