TBSS intake vs stock
 

searched lots of threads, couldnt find what i wanted to know...

my motor is not making the power i thought it should, and the only major restriction i can think of is my stock 4.8 intake manifold on it.

i thought all the truck manifolds were the same, but after seeing a stock lq9 mani, it looked much bigger than mine, and the TBSS mani looked larger as well, looked like they would flow a bit more than mine.

i was looking at a TBSS mani as an upgrade, just not sure if its worth the trouble of doing, and i'm also not sure if my throttle body would bolt up without some sort of adapter plate?

whats your thoughts on this?

my motor peaked fairly low on the dyno, around 5500 if i remember right, which seemed fairly low. cam is around a 232 duration on a 112, heads are patriot cnc'd and i think they are 317 castings...

will the TBSS mani solve my problems?

I can confirm the LQ9 intake and 4.8 intake is the same I had them side by side and I'm using the 4.8 intake on my 6.0 no problems. I've read the tbss intake is a good gain over our intakes on the top end while still keeping good low torque,

the differance is newer stuff is 4 bolt 90mm TB
old is 78mm 3 bolt TB

IMO the itake itself is only as good as the hole letting air in...getting a intake that uses the larger throttlebody wil have to let more air in.

did you dyno with the cut out open-might lose some power there?

i did both, gained 21 or so rwhp with it open.

i guess it wouldnt do me much good without a 90mm TB then. i mean, if i go with a TBSS intake and then adapt it right back down to a 78mm, i would be pissing in the wind right?

correct. but you could get a 90mm t-body to go with it. dr x makes an adapter to keep the dbw.

www dot torquerush dot com. the adapter is probably the most expensive part of the swap. it is pretty easy. if you go for it be sure to use the car style throttle body.

By the time you convert to the TBSS intake my god you have damn near $800 in everything. You could damn neat put a FAST 90 setup on it

:stupid: thats what i was thinking. If you are gonna go through all the trouble to switch it out might as well just spend a little more cash and get something that you know is going to perform better. Unless of course you dont have the extra cash then you can only do what you can do. just my .02.

i tend to agree. i wasnt aware it wasnt a plug and play app... havent researched it as thorough as i should have yet, just brainstorming on it...

it seems that adapter was over $200, and the $150-200 for the intake/TB....

damnit, i hate that lsx parts are so freekin expensive. my old SB 350 days make me really feel like companies are ripping us.. parts were soooo much cheaper!

looks like i may not go this route.

you can get the TBSS intake from gmpartsdirect for around 150 shipped and around 165 shipped for the TBSS 90mm DBW TB, and then the dr x adaptor for around 200. I have a TBSS intake already and need to get the TB and adaptor to swap onto my 2003 5.3.

You will see some gains, but may be better off with something like the new weiand composite intake and 90MM TB, you will still need the adaptor, but that intake i think will give you more power and tq for the money spent versus the TBSS intake, unless you want to keep it stock looking. Could also send the TBSS intake and TB to ls2portworks.com and have them ported for even more gains across the board, i plan to do this for mine.

i was just looking at a TBSS manifold/tb/fuel rail setup for $150 shipped... seemed like a pretty good deal, but would still need the adapter.

if i did it, i would probably port it myself and sand/paint the mani also.. being my engine covers probably wouldnt fit it.

dyno's dont mean nothing!

Are you sure it is not something other than the intake that is restricting power? have you checked everything else?

are the truck injectors the same as the tbss?

I am going to revoke my statement from earlier - I am going to be upgrading to a TBSS intake as well with my setup. My ported heads are demanding more than the intake can supply. I found a new TBSS intake complete with fuel rails, injectors and TB for $230 shipped. Another $200 or so in a Dr. X harness and I should be able to do this for around $500 or less. Still better than cutting brackets, relocating pulleys, etc. :nod: Now, keep in mind some will tell you the 90mm hole bottlenecks down to 78mm, then opens back up into a 90mm opening. Some will say this is restrictive, I think it's intelligent design at work and GM is trying to produce a venturi effect that will enhance torque everywhere but still give you good flow up top. For the price I'm getting it at, if I don't like the setup, I can sell it all for what I'll have stuck into it. If I understand everything correctly the intake is a direct drop on except for one vacuum line and the TB adaptor. I wonder if a TBSS intake cover will work under the hood.......

i think you and i are in the same boat here man.

my exhaust isnt making my power suffer, neither is yours. the tunes are close enough... i am almost positive it would have to be my stock 4.8 intake.. and your stock intake as well. i dyno'd cutouts open and closed... still wasnt happy with the power levels..

+1, I agree. Say could you send me a link to your results as well?

link sent ;)

may we figure this out :chug:

I'm just having a hard time believing that your intake is restricting you, especially at only 5200 rpm. There are plenty of accounts of the truck intake pulling well into the 6000's

same intake, same dyno, my 4.8 peaked at +6000.... i think around 6200 or so ?

this motor peaked way lower, but has more volume, better flowing heads and a much bigger cam..

i not know?

well, I am very interested to see your results! If I had to change I'd go with the ls6 intake myself, simply for the aesthetics!

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!

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.

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....

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.

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

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.

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.

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.

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.

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.

Your motor is smaller too though. 20CID at higher RPM's may be enough to tip the scales. What heads are you running along with cam?

i believe he has patriot LS6 heads and 226/226 112LSA,

i am with rgvsierra, take it to the track and dial it in there, i believe alot of people get hooked on dyno #'s,:confused:

here is my dyno with the truck intake and ran a best of 12.4's, power stayed up there all the way to 7250rpm where my rev limiter is set at, thats why its hard for me to swap to a LS6 intake cause i dont think it will help any?

this is on a 05 LQ4, with stock heads, 226/226 112

http://i87.photobucket.com/albums/k1...002/APDYNO.jpg

Damn!!! That is one good running truck.... Look at that TQ curve....

ok now that anselmo posted the 6.0 on stock heads pulling to 7k, and my smaller motor with the same exact cam and P&P heads only pulls to 6500 before it plumits...

Do yall use the same tuner? Just tryin to rule that out....

same one...

Cool, that rules out the tuner...

same tuner, same gears, same converter, same cam,

the only real difference is our CI and heads.

I think what we're seeing here is a trend that when the efficiency of the intake port is increased, we're actually cutting our own throats because no longer is the truck intake manifold "tuned" to the proper flow range in which the heads and cam are working. Plenum size needs to increase along with intake runner volume to maintain and keep up with the new flow intake. I would have been better off I think had I left the 243 heads alone. Now that I fubared the heads by having them ported I am going to consider porting the truck intake or upgrading to a TBSS intake, whatever is more efficiently priced.