Well i case you haven't figured it out i plan on dropping in the LS4 into my 85 Fiero GT and raise a little hell with the local import movement. If you guys have any requests for pics let me know and i'll see about getting them. Well enjoy !

Complete engine
https://ls1tech.com/forums/attachmen...hmentid=&stc=1

The front with all accesories removed
https://ls1tech.com/forums/attachmen...hmentid=&stc=1

The bottleneck in the intake manifold
https://ls1tech.com/forums/attachmen...hmentid=&stc=1

 

What is the deal with the intake manifold pic. . . .can you give me a little more bearing to what I am looking at??

 

What a shitty design intake! Looks like there's alot of improvement there.

 

I measured the throttle body and it measured around 76mm in case you guys didn't know. The intake manifold seems to have a resriction in it right behind the TB. The DoD oil pressure switch seems to occupy some room that might make an LS1/LS6/F.A.S.T. intake swap impossible . Unless of course you machined down the boss re-threaded it and attached a 90* elbow to attach the switch and make some room.

 

That pic is of the intake manifold directly behind the throtlle body. Pretty much a short runner that dumps into the main portion of the intake manifold.

 

Well this may be a silly assumption, but if i found out some way to remove that restriction plate i could say jump 20-30 hp easy because of the large amount of extra air i could suck in.

 

Eddie it isn't really a plate it's the shape of the neck from the throttle body to the main chamber of the manifold. It tapers down like a cone.

 

Some engineer probably placed that in the intake for a good reason... probably to do alot with resonance and noise cancelation in the intake. Or something to do with the 45 degree air intake setup prior to the T-body that it needs that there to make sure all the cylinders get equal air flow. Beingthe fact its cone shaped porbably has more impact on increasing velocity, which owuld boost torque at low speeds.

Anyone ever see one of the RJS power plates for grand nationals?? its this plate that goes under the dog house of the intake and looks like a HUGE restrictor, but it redirects and guides airflow equally to all cylinders, they get like a 25-30 hp increase from that part alone!

If you can get ahold of the "how to build hi-po LS1/LS6 engines" book they havea whole chapter about the intake manifold design. and how important certain parts of it are like the 3 upright pilars in the intake etc...

 

needless to say, i won't be doing a cam install.

eff that noise

 

Fiero, did you yank the cam at all to see if they use different lobe shapes with smaller base circles on the DOD cylinders?

My fear is with a bigger cam that it would work fine, till the DOD hit... because it uses the two piece lifters and they essentially collapse and the outer body moves up and down while the center stay stationary. What happens if you increase lift then... The way i figure it, it would bottom out the inner, stationary portion of the lifter and would contact the outter body when the lobe comes up to the tip of its lift point and opening the valves and negating the DOD....

Until i know specs on how much travel there is on the inside of the lifter, i dont think im gonna try a cam anytime soon either. Yeah the lifter its self can handle .595" lift, but can it deal with that when its collapsed for DOD mode is what im worried about.

Looks like those 1.8 ratio rockers and good springs/pushrods are going to be the only realistic way to slightly increase lift/duration... Not 50hp's worth like a cam would...

Unles you could shut the DOD off is the only way... Then the question... quicker car that cant get traction and drives through trannies and crappy MPG and is a nightmare to install the cam... or pretty quick car with rockers and bolt ons, with Ok mileage...

 

same here, to me, it seems rockers are lookin really good right now. aside from that, im not going to pull the whole front half of the motor apart to do a cam.

 

Lol yeah... among having to drop the entire k member/ motor down some to get the cam to come out under the frame rail too! Ive helped do cam's in L67 supercharged 3.8's in these W bodies, and they get lucky by only having to drop one side of the K member... not so sure the LS4 would be so willing, being its longer than the 3.8 and would tilt into the frame rail before dropping far enough.

Or you could just punch a hole in the body/fenderwell to slide the cam out through bwahahahahah ive heard of people doing that on L67 W bodies!

Getting that crank pulley off and water pump look to be quite the **** show!

Swapping plugs wasnt as bad as i thought, just kneeling on the rad support doing blind work to change the plugs, had to bend the tranny dipstick tube out of the way to get at #8 clearly though with a socket.

Anyway... back on topic

 

the plugs are easy, the wires are a bitch.

yea, i don't see myself doing the cam, unless i have a spare motor laying around

 

I wanted to cam mine to get rid of the DoD, but after reading a few of you posts, I'll prob just drive and enjoy my car, and dump the extra $$$ in the Camaro.

Thanks for the pics!

 

Lol im just the opposite end of that spectrum now... Im done modding the camaro... got my low 10s out of it, now ive got this dumb idea to make my daily driver a mini version of the camaro lol

I really gotta woody to do a GN or a supercharged L67 3.8 GTP build now to... ugghhh this car **** is a disease!

 

I'll drink to that!!!

We wouldn't be car guys if we didn't wrench on everything we had, right? (I'd self-implode if I owned a minivan). Missed my opportunity on a GN in the early '90s when I had an '85 MCSS. The wife wanted a car like it, but only with a 6-cyl. She shot it down 'cause she didn't want a black car. LOL!

 

should have found a t-type



fiero, do you plan on using the stock intake manfiold? if not, i'll take it off your hands, im really curious to do some numbers testing on it. there is a bottle neck somewhere in this car, be it intake, exhaust, or cam. i know it's not the heads, nor is it the bottom end.

why do i think this?
well the truck 5.3 is pushing more power then us. {321 vs 303}

there has got to be a bottle neck somewhere in it

 

Truth! T-Types were really scarce back then, friend's Dad had a blue one ... sweet!

 

im sure one of these years we'll figure something out. or i might end up doing it.

it seems people in the gxp world are too chicken to do anything, and people on here seem more apt to do something, then sit around and wait for someone {IE ME} to do something, so they can go off and copy it.

dunno, just my simple observation

 

Second that!

Was going to get a Granetelli Motorsports MAF like on my Z28SS, but another thread said something about you'd need programming and they were ineffective.

I programmed and MAF'd the Z at the same time, which combined caused the Z to pick the nose up on launch as well as down shiffting / accelerating out of corners. I actually had a smile the first time I took it out, as it produced an outstanding SOP feel along with the front end lift. Thought it was money well spent.

Z has great intake set-up. Used the SLP stainless cold intake box that rams air from the front of the AC into the lid (direct charge) - the W-Body intakes from a small opening behind the headlight. A cleaner flow should help that out, like the old LT1 / Mustang CAI that pulled from the bottom of the front fender.

I don't know anything about the MCSS cross-over pipe ... my Z has dual cat LGM 3" Y-Pipe feeding 3" GMMG chambered. MCSS's Magnaflow mufflers are a clean flow through design, but have 2.5" pipes (which are way better than the stock 1 3/4" pipes).

I also have a 160* stat in the Z, but I read somewhere that the LS2 / LS4's don't take any advantage of them.