Currently have Flowtech 11116FLT headers. I'm looking to replace them with something else. I was thinking about getting the stock manifolds available for my car, but I'm concerned about the loss in performance. How much performance loss is it (approximately) to go with the stock manifolds vs some kind of headers. I'm thinking it might be worth getting rid of the spaghetti mess that are headers and go with a nice clean look and make some more room. Of course I still want the car to be fast!

I appreciate any input. Thank you!!

 

Hard to speculate without knowing the rest of the combo. To grossly generalize, you'd possibly be looking at a 10% reduction of power on the top end going from shorties to stock manifolds.

 

The worst part of flotec is the Y pipe make a new one

 

I'm not worried about the y-pipe. The one I have now I made myself. Eventually, the exhaust will get done professionally, including the y-pipe.

 

Read about what vinny R did here: https://www.thirdgen.org/forums/tpi/...ml#post6337072

 

I'm not sure if it's the beer that I'm drinking right now or what, but I'm not sure what Vinny did. So, did he keep the original manifolds? Can someone decipher what he did? Maybe Vinny can chime in. Sorry peeps, but it's Friday and this is my day to drink up!

 

I can agree that reading to find out about manifolds was futile. I don’t have the attention span.

 

I'd think with the 383 you'd be giving up more power than you'd like. Those manifolds are pretty restrictive and the factory type Y pipe is pretty bad too, unless your setup would be the dual cat exhaust. I'd stay with headers and good free flowing pipes.

 

Yeah, I'm going to agree with you. Headers it is.

 

The nice thing about manifolds is the car was designed for them. you got places to park your spark plugs, spark plug wires and can generally have better access for maintenance. they are also less likely to leak or cause heat problems. but if you want power, headers it is.

 

Headers will ALWAYS out-flow manifolds, and help the engine produce more power. Personally, I don't wanna deal with them in my thirdgen, and since I'm not going racing, I don't have to. My H.O. exhaust system will be just fine...

 

Outside of things like tri-y headers, various collector shapes (DeLaval noises...)... HP is just proportionate to flow, to the crossectional area. If a manifold's most restrictive part is the same as a header they will likely make very close to the same HP. Most of the cheaper headers that people run have smaller tubes than the ports in the manifolds and only a slightly larger collector than the outlet of the HP manifolds, so they should make similar peak horsepower and should even run similar times at the track.

The reason that people comment on how much more power they seem to have with headers, even shorty headers is that what the longer tubes do give you is better midrange/torque peak tuning. In essence, the peak of the graph is the same, but the area under the graph is greater with headers, so driving them around it feels like you have more power because you have more torque available at points outside of the HP peak. This also make for a significant increase in MPG.

Have you worked on both? Spark plugs are no picnic with either, but they are substantially easier with most headers. I can do all 8 with the typical 1-5/8" tube headers on a car in 10-20minutes with only minor cussing (I have a pass through socket set that has some combination of parts that lets me get ALL 8 out with headers, where with manifolds you typically end up using all sorts of combinations of sockets and wrenches, the heat sheilds are always in the way.... With manifolds it takes me that long to figure out how to touch the back plugs, especially 5 and 7 on the driver's side with manifolds.

 

wasn't referring to spark plugs. was referring to other items, i.e. the starter, and other items that don't make your car go any faster, but sure are nice to have. Factory manifolds also have a nice little gadget where you can secure your spark plug wires. also a nice feature. not knocking headers, just contrasting them.

 

Spark plugs are EASY in these cars IF you get rid of the A.I.R. system.
Now back to our regularly scheduled program...

 

Not an option for everyone.

 

I know. It was kind of a "tongue-in-cheek" comment...

 

I'm Running Hedman Long tubes, they sound good and aren't that loud really, i've heard much louder, but i think they will sound pretty good with and exhaust system

 

I've always found all the extra brackets and crap annoying, with manifolds, of course, I installed my first set of headers on one of these cars in 1991, I've had a while to figure out how to make all this stuff work and easier to work around 😉

That somewhat depends on how big your hands are. I find them next to impossible on the driver's side what the air tubes installed, and no matter what you do with manifolds they're not as easy as with most headers with 1-1/2 and 1-5/8" primary tubes.

The way things are going there's a good chance that it won't be an option for anyone soon. Look into the RPM act and support SEMA.

If it wasn't for the transmission fitment weirdness (and honestly I haven't looked to see how bad it really is), I would argue that the headman long tubes should be the best deal on moderate builds and if you care about MPG and midrange on a v8 car. The Headman "shorties" (not really shorties, more like 3/4 length headers) are probably the second best.

 

My plugs are easier to get to with my Hooker shorties. I have fought a lil slight leak since I put them on in Feb though they can be frustrating, need to go on and take one off and put my new gasket on.

 

Good to know about those Hedman long tube headers. I've kept the ones I have, but when it's time, I'll definitely look into those. Thanks!

 

the hooker and headman "shorties" (again, they're longer than most shorties), are both decent designs, the only real difference between the 2 is the collectors exit at slightly different angles so the y-pipe has to be different. Both have fairly thin flanges and to prevent leaks make sure you use a good gasket (give it a coat of copper coat if it makes you feel better), and then snug down all the bolts a little at a time so they are pulled evenly to the flange. On the collector end, well I hate 3 bolt collectors and I cut them off and weld on v-bands.



This was probably the 3rd or 4th time this pair of headman ones were blasted and re-coated, 4th car they've been in.



Adding a v-band flange to this one.



Modified y-pipe I made for this set. It looks kind of rough but that's mostly because the high temp paint is still wet in places giving things all sorts of different textures/colors.