READ: my crazy intake idea

[dohcfiend]

i don't ever plan on attempting this. so it is more like a what would happen if i did this? your opinions.

recently i can across a cadi N* intake assy. and i was told it had 29lb injectors in it. so i was thinking about my lt-1 firebird but come to find out there is a good chance i was misinformed and in fact they are like 19's

so i am going to sell it soon to break even. What if some1 disconnected the tb neck on a 96-97 3.4 dohc intake, made an adapter plate, and bolted up the tb from the N* at that huge hole?

in theory what effects would it have on the engine?

[Lyle's GTP]

Well once you retuned the fuel to handle the increase of air flow. I'm sure you would have a signifigant increase in power. But to get all the benefits of this mod the heads and intake would surely have to be ported to allow for a controlled flow of air into the beast. Along with this you would also need to upgrade your exhaust as well.

Lyle

[dohcfiend]

wow .

perhaps i should keep the tb then and actually attempt it 1 day. or at least adapt it to the stock tb location.

i bet it would do wonders if it were boosted then(if properly tuned)?

btw does any1 know what size a set of injectors for a 99 northstar in psi?

[dykz34]

Well once you retuned the fuel to handle the increase of air flow. I'm sure you would have a signifigant increase in power. But to get all the benefits of this mod the heads and intake would surely have to be ported to allow for a controlled flow of air into the beast. Along with this you would also need to upgrade your exhaust as well.

Lyle

Ummm... why would you need to retune the car? The car has either a MAP or MAF sensor that will compensate....

I don't think you'd have to port the heads, either. These heads flow DAMN well for stock...

The only thing you would have to do if you put a 75mm TB on is port the intake arm or make a new one that is 75mm throughout (otherwise you'll just have a bottleneck in the system).

[dykz34]

Also, I don't know if you would even need an adapter plate for the Northstar TB.... I believe that the bolt holes on the 96/7 intake arm are a fairly common GM size. The only other thing that might not line up would be the IAC passage.

[dohcfiend]

well if all goes well i might just do a mock ^ to gather data for the future when i go through my stage 1 upgrade package and I have to pull the plenum.

if i could make it work would the larger tb and intake arm hurt tq or help it? i would guess hurt, isn't velocity what makes torque? o well too much torque is a bad thing anyway, shit starts to break with too much torque.

i like it when some1 pulls off the line and i come shooting past them(dashing their hopes) mu hu ha ha ha ha

i think dyk34 has a point too. these heads flow damn good. they have large valves too.

my guess would be a cam regrind, bigger injectors, and a computer chip reprogram to maximize such an upgrade (that is if u deleted the neck and bolted up the tb to that huge ass hole). well it might be something to kick around for u boost masters out there.

IMO yes, a retune but no on the heads and exhaust. keep in mind this is just my opinion and it is not meant to criticize any1 and any relevant replies to this thread are valued and appreciated by me. cause now in these brief hours it has went from what if to maybe i should try it(the less xtreme version) thanx to every1's input. who knows if any "real" gains come of this, it would be that much more sweet, plus northstar intake assemblies are going for cheap now. i won mine for a mere 25 bucks.

if i ever get ahold of an xtra tb neck i might attempt it and take it to the dyno for actual numbers instead of my opinion.

sorry for the eye stressing reply, but i am fucked up and psyched now.

[dohcfiend]

just from looking at my initial plan of action for the iac would be to cut the entire section out of a 3.4 dohc tb, close it down to 2 tubes, run 1 into the intake tube and the other in the egr hole in the spacer behind the tb. also i wonder if the earlier northstar tb's have iac already on them?

next question, can the stock tb and tb neck be bored to 75mm? if so there will be no point but i am pretty sure the N* can be taken further whereas the stocker might be maxed at 75mm.

[dykz34]

I don't know if you could get the entire throttle body arm that big... You could make a custom one though using 3" pipe. Or, like you said, you could try just bolting the TB to the plenum with an adapter flange.

[dohcfiend]

hey, i did a little research and the 96 and up N* tb's have the internal iac valve just like our cars.

[dykz34]

Cool, now all you gotta do is measure the distance from the bolt centers to see if it will bolt up to the stock flange...

[dohcfiend]

1 thing at a time.

[dykz34]

Do you have a dial caliper? If so... get goin!

[dohcfiend]

shit, i need a tb neck 1st. i sure as hell am not taking the one off of my car.

I am working on getting another tb with internal iac valve.

and what is a dial caliper?

[dykz34]

A dial caliper is a very accurate measuring device... here's one on eBay: http://cgi.ebay.com/ws/eBayISAPI.dll...844461896&rd=1

All you need to do is find the distance between the bottom holes, and then the height of top hole in relation to the bottom holes. (Plus, I'm sure it's safe to assume that the top hole is centered)

[dohcfiend]

damn dude, u are right. the hole in the n* tb is HUGE compared to the hole on the tb neck, but the hole in the plenum is between 75-77 mm. If i were to make a new neck that was 75mm all the way it would work. i was thinking about using some aluminum tubing like they have for those CAI kits and taking it to an exhaust shop and have it bent there so i can play around with the angles to get them as small as possible. unless the exhaust shop can't handle that diameter and then i guess i will have some1 heat it and manually bend it.

do u think it would work? also that machine shop i deal with all the welders are about worthless except for the guy that does all the aluminum welding, he is badass. also by using a different tb neck that way if it kills my torque too bad i can switch back. perhaps i can make the tube a little shorter than the stocker to compensate for the loss in velocity, what do u think?

my guestimation is it would hurt my torque but once this thing started revving it should show some gain hopefully