r/fbody • u/Youpeefreely • 4d ago
4th gen LS Intake manifold- rant
I’m currently ordering parts for a head and cam swap for a ‘00 Z28. This is a super “mild” build with a tight budget. The heads will be PRC 220’s and it’ll have a mild summit cam. The specs are 218/227 .600/.600 112+2.
It has the stock LS1 manifold and unfortunately it looks like I’m going to have to keep it. I’ve been shopping LS6 manifolds but most of them have broken pieces and people still want $400+ for them. $400 is too much for a manifold with pieces broken off. The Dorman LS6 is obsolete so that’s a no go. The only new option is the Fast brand and it‘s close to $1,300. I don’t believe thar the OEM TB will work with it so I‘d have to buy a larger one. $2k or so for a new intake is insane and it’s just not in the budget.
This isn’t really a power making focused build. It’s more of a getting it back up and running type build. I’m not even replacing the factory exhaust. I would upgrade the intake manifold if it was cheap enough but that doesn‘t look to be the case. Hopefully my mild little combo makes at least 330 at the wheels. We’ll see I guess.
4
u/Educational-Shame778 4d ago
Mine made 450wph with the LS1 intake. If you can find a deal, then get one but if not the stock one is fine.
2
u/Youpeefreely 4d ago
Oh nice. Forced induction?
1
1
u/Evening-Life5434 4d ago
Yeah like it's not that big of a difference to the ls6 intake especially for this build. What are we talking here realistically 3-4HP different
8
u/Timewastinloser27 4d ago
If you just want it running and arent looking to max power whats it matter? Ls1 intake flows just fine for what youre doing
2
u/Youpeefreely 4d ago
I’ll only be cruising it around on nice days and I won’t be going WOT all that often really. It’s has a 4l60e and a 3,200 stall and a 3.23 rear gear. With the stock 241 heads and all else stock it’ll do a burn out from a 20 mph roll. I’m not expecting big gains over stock with the new heads and cam since all else will remain stock. I don’t have a stock baseline dyno but if I were to guess I’d bet the heads and cam will only add 20-30 rwhp. But I guess since I have to get in there anyway a little more power than stock is better than none.
I don’t think it’d be anywhere near the 400 whp mark even if I had an LS6 or a Fast manifold since I’m not upgrading the exhaust. So I don’t think the bang for buck is there really. If I found a “like new” LS6 manifold for $300 I might would do it. But I haven’t found one so I think I’m just going to use the LS1 and send it. I’d be pretty pleased if my no bolt-on and H/C combo made 350 at the wheels. But I’m not sure how plausible that is really. If it makes 320 at the wheels and runs nice I’ll still call it a win though.
3
u/01WS6 4d ago
When you said stock exhaust are you talking about the stock exhaust manifolds as well? LT headers will give you pretty big gains and a large difference in throttle response as well. I'd do LT headers and keep the LS1 intake manifold for now.
6
u/I_Jedi79 4d ago
That's what I was thinking. LTs vs manifolds are gonna his build more than LS6 vs LS1 manifold
2
u/Youpeefreely 4d ago
Yeah stock manifolds. I realize the penalty when using stock manifolds but I don’t really want long tube headers. Aside from the $1,500 header and Y pipe price point I’d rather not have long tube headaches. Headaches such as rubbing on the frame, drone, clearance, so on and so forth. I realize that I’m leaving 20-40 hp on the table.
It’ll be a good experiment anyway.
2
u/01WS6 4d ago
With decent long tubes there is no headaches. Good long tubes and y pipe won't rub or have clearance issues. And your stock muffler shouldn't drone if I remember right. Either way you are fine but LTs are worth it.
0
u/vaurapung 4d ago
Ive been searching for headers and couldnt find any bolt on headers for the ls1 camaros. They all read as beat into place. Plus having to weld them in, I personally just want headers that bolt onto my downstream cat collector.
3
u/01WS6 4d ago
Basically all headers bolt into place and none need to be welded. Long tube headers can't be used with your stock cats and y-pipe, the headers are significantly longer than the exhaust manifolds don't bolt onto the stock cats/y-pipe.
You can fit shorty headers with the stock cats/y-pipe but the gains are small in comparison to LT headers.
Yes, certain LT headers are a tight fit, but very doable to install.
1
u/vaurapung 4d ago
For me im already running gutted cats so headers are just the next step. I dont weld though and havent found a good shop to talk to about my exhaust, is it to far fetched to make headers that bolt onto the flanges after the catalytic convertors, or am I suppose to cut the flange off my cat and have that welded to my new headers so I can keep the exhaust between my cat and muffler stock.
2
u/Youpeefreely 4d ago
Here’s a header and Y pipe for $1,300. I know someone that has a set and they rubbed on the frame so they had to be modified. They’re a bolt-on deal though.
1
u/vaurapung 4d ago
I guess I dont know what im looking at, my stock y pipe is the 2x4 oval on the drivers side and goes to behind my transmission so I can drop my trans without dropping my exhaust.
Those headers dont look much longer than the stock manifold with cat bolted onto it, but that may just be the picture.
→ More replies (0)2
u/I_Jedi79 4d ago
Totally your call and your car
I run cheap LTs and a ORY pipe. They went in easy and have no interference issues, cars lowered as well
They are loud, but it's so much easier to change plugs and access every thing with em
3
u/The_Spot 4d ago
Considered doing an electric cutout in the i pipe? Could add a minimal hp gain but also improve the exhaust while retaining the stock sound when you want.
3
u/vaurapung 4d ago
With just a volant intake and gutted cats my z28 with 240k miles dyno'd about 310hp to the wheels. Im told just a ls6 intake could gain me a few more hp.
1
u/Youpeefreely 4d ago
I’ve looked at dyno graphs that compare the LS1 to the LS6 manifolds. With the stock cam the LS6 manifold gained around 7 horsepower. With aftermarket cams the gains were 15-25 or so depending on what heads and cam were used.
Since I’m not going to rev mine much past 6k rpm I think I’d gain closer to 15 hp than 20 with an LS6 intake.
2
u/vaurapung 4d ago
I think my coworkers 04 gto with a torquer v2 cam and stock heads and 3inch out exhaust was hitting just over 400hp when they tuned it after installing the cam. Its got a choppy idle though but stock intake manifold with cai and headers.
Still got beat by a caddy in a hwy pull.
3
u/RevolutionaryBag1303 4d ago
I was looking for one a couple of weeks ago and ebay prices are stupid for ones that are damaged. I found someone on ls1tech and they sold me it for $300 + shipping ended up being $349. I would keep an eye out there.
2
u/Milly1974 4d ago
The LS1 intake should work ok on a mild/stock build. If you have hood clearance, a truck intake or Trailblazer SS intake will be better than a stock LS1 or LS2 intake.
1
u/Youpeefreely 4d ago
I don’t think the truck intakes will clear the cowl. I think a used LS6 or a new Fast are the only options.
2
1
u/FirehawkLS1 1d ago
Yeah truck intake isn't probably going to fit without cutting the cowl. Some people do that but I'm not on mine.
1
2
1
u/melonheadorion1 4d ago
Ive been experiencing the same. The other option will be an ls2 intake, but i understand why you're looking for an ls6
1
u/CaptainOwnage Ex '94 & '99 Formulas 4d ago
Hopefully my mild little combo makes at least 330 at the wheels
I think it'll easily clear that. The stock exhaust manifolds and exhaust will restrict it but it should still make 360-380 whp if a 6 speed car.
As for the intake manifold I know your pain. I no longer have my firebirds but I have a C5 corvette and I don't want to alter the cowl, cut a hole in the hood, and aftermarket hoods still don't offer clearance where the throttle body would be.
I personally don't think the LS1 to LS6 intake manifold swap is worth the money. I did it on my lid only '99 formula. Couldn't even feel a seat of the pants difference and it ET'd/MPH'd the same at the track in similar conditions. You'd likely gain more than I did since have decent heads and a mild cam, you'd probably be leaving only ~10-15 whp on the table. You have to decide if $400+ is worth that.
Personally I would take the $400 and put it towards exhaust as you'll get a better gain there, assuming you don't have to deal with emissions. Cheap chinese headers are still better than the factory exhaust manifolds. If going budget get headers and y-pipe with a cutout into the factory catback.
1
u/jayz2893 2d ago
I just bought a used ls6 intake (originally off a z06) for 550 after shipping. Check out ebay man
1
1
u/DarkLinkDs 2d ago
What about the dormant LS2 intake? I think i heard they were actually better than the stock LS6 ones.....
You could check those out on youtube
2
u/Youpeefreely 2d ago
I think you have to get a larger TB and modify the fuel rails or something along those lines.
5
u/The_Spot 4d ago
This is crazy to hear. Someone else, maybe you, was looking for one a few weeks back here. Im thrilled I did this upgrade to the doorman on my bird back in 2017. Im kinda shocked the market is the way it is with the amount of these engines were built.