ZO6Ted

I thought the TBSS was an LS2. Is it an LS2 intake or something else? If so, I understand that the LS6 is the better one to have (even with only a 78tb) other than a fast...but at a cost. I recall the LS2 being down about 5 or so horses on a stock motor. Just food for thought. Good luck!

hirdlej

iTrader: (31)

I have a theory as to what's going on with our setups (sickRED). You and I are very similar and should be making around 400 RWHP and 400-420RWTQ. If there are any intake or induction experts please chime in but here it goes.

In a nutshell, our motors are designed so well (no smartass comments please) that they're not getting the cfm of air required with each draw of the intake stroke. Bear with me here as I elaborate.......

You can have joe blow with a stock LQ4, TR224 cam and long tubes, a cold air intake and a tune with NOTHING ELSE DONE but with all other variables the same, he's going to make more power than us and here's why. (remember this is pure theory) When the intake valve opens immediatly after the exhaust stroke, and the piston is traveling downward, on a standard port the air doesn't "slip in" or "slide in" with as much acceleration with all the casting material left as it would if it's ported. The intake port charge is actually kind of stagnant momentarily before it's drawn into the cylinder thus moving less CFM and not potentially "robbing" or taking air from otherwise available intake runners (in the plenum area). With ported heads, and ones that flow exceptionally well, the demand for CFM increases so dramatically that all the cylinders are actually working AGAINST eachother in the higher RPM range and they're fighting over who gets more air. This causes almost a "static" or "cluttered" effect of the intake port pulses. FI guys never see problems like this as they force the air in to make it do what they want it to do. Remember, this is just theory but I think this is what you and I are looking at. I think with better intake manifolds we can attain our 400RWHP level along with even more torque if we plan this right. I don't know though if this can be done with a TBSS intake as after the 90mm opening it bottles down to a 78mm restriction, then opens up again. I don't know if this is gm engineering trying to create a venturi effect for more torque in a heavy truck of if this is an oversight.

BlackGMC

iTrader: (31)

Have yall looked at dyno charts over on tech? I am sure there are tons of similar setups over there, maybe they are your answer....

zippy

I've installed 2 of the TBSS intakes onto standard trucks and they seem to have picked up some power. We never did get any dyno numbers though. They come on the TB 5.3L, 6.0L, SSR 5.3L, 6.0L, and I believe it's the same intake as the NNBS cathedral port trucks come with.

Phantom

iTrader: (16)

if you gained 21rwhp with your cutout open, don't you think maybe your exhaust could be holding you back instead of your intake?

hirdlej

iTrader: (31)

Was this a clean and straight forward install when you did this? No splicing of wires? What'd you do about the drive by wire 90mm throttle body? I've heard there's a few throttle bodies one the blade tips forward and the other the blade backwards. If your TAC isn't compatible with the one you have, it won't open, is this true? Obviously I know the dr.x harness is needed.

TXsilverado

iTrader: (19)

im not guna get into all of the debates that may be going (havent read the entire thread) but i serously doubt that the truck intake manifold is restricting your 4.8. AP pulled the truck intake to damn near 7000 rpm.

the 6.0 intake and the 4.8 intake are the same...no need to call it a 4.8 intake. its just the truck intake. if your still stuck on the manifold being your restriction later down the road i may have a complete LS6 intake swap kit ready to sale in the next few months if weiand doesnt get their chit together.

take it to the track and run it to determine if its down on power. dont put all of your eggs into a dyno. dyno results tell me i should be shifting 66-6700 rpm...track results PROVE that im faster shifting 6900 rpm.

zippy

I think that once you get past 400FWHP or so you are restricted by the stock truck intake. It was designed around the airflow range of 300hp and using GM's 80% theory that puts the airflow peak at 375hp. Of course with raising efficiency you can make more power with the same airflow if you increase that. It will keep making more power, but power will fall off with a truck intake where it wouldn't with a car intake. I agree that calling it a 4.8L intake is pointless when it's just a truck intake, but so is the LS6 intake. It's actually just an 01' and up car intake and not specific to the LS6. I remember one of the guys going to the track and accidently moving his shift points down to 6000 from 6500 and ran about the same time as he did shifting higher. Think about this, how many with the first design truck intake have made over 380RWHP? The intakes for the Gen IV engines do flow alot better and of course were designed initially for more flow therefore they have more room to grow.

As for the intake installs, They looked mostly stock when done, but I don't remember all of the details. I believe we used the Corvette TB and a Dr. X harness. I don't remember if we used the L59 injectors or the marine injectors, but I remember injectors being an issue some how.

MGMC

iTrader: (46)

also what did you do with the vacum line since the tbss has the inline vs truck having the internal? i just got a 08'tbss manifold/rail/injectors/tb and will be doing this swap soon. so far i have gathered:
-drx harness
-try to re-use the truck fuel rail/injectors by drilling new holes on rail or using the tbss ones by splicing in the diffrent style connector.
-cap off fwd vacuum line and delete code/ or get the inline from another tbss.

TXsilverado

iTrader: (19)

sure but calling it ls6 intake differenciates it from the ls1 intake that looked almost identical. i am a little over 400 rwhp and so far i have seen zero gains from the ls6 intake manifold over the truck manifold.