Write-Up: Northstar Throttle Body Install

Should only need this mod if you go to a larger blower, or are flowing more than 11,500 MAFF, but here's a write-up:

http://www.davetech.net/car-northstar.htm

my friend is selling one for pretty cheap with all the stuff. do you think it would be a worthy mod? i dont think any other riv owners have installed a N* TB. would my 96 MAF (different than the 97+ IIRC) plug up to the LQ4 maf sensor? he has it set up for a 98 GTP MAF right now but he also has the LQ4 adapter. would i have to tune it to make it work? i (zzp) may be P&P my blower too, so it would help out more then.
TIA

ok a quick search pulled up some info from zzp website;
aparently i must reprogram my pcm for the different MAF but they have a table i can import. the guy that is selling it has a powertuner with the L67 open package. i guess my next question is will their new software tune a riv? any harm in trying?

I would be concerned as to whether or not there is any support for 96's. All i know of is 97's+ for all 3800's.

the gtp and regals changed in 97 thats why all the sites say 97 but as far as i know the 96 rivs will work too. it's still a s/c series 2 L67 with obdII pcm just a slightly different transmission.

You could just get an AFC 2.0 which scales the MAF. Ive got one, that I probably dont need since I have HPTUNERS. Otherwise, if he has an open l67 package, its worth a try.

Some members are using the northstar throttle bodies, but i've been reading around and some are saying it doesn't make much of a difference.. if any of you are using them, IS there an improvement? Would I have to go back to using a 4 inch intake tube to notice it? also is it the throttle body from the 4.0 N* or is it the 4.6, because I was searching around on car-part.com for used ones and I found some for about 60 bucks in my area off of 96 Devilles, but they use the 4.6, no sure if that would fit or not. If that does infact fit, I need a N* adapter plate, how much do those run?

I run the N* and it made a dramatic improvement in throttle response. I also run the Gen V so I don't know how much of an aprovement just the TB would be. I believe all N* TB are the same whether they come off the 4.0 or 4.5. If I am not mistaken the N* is 77mm compared to stock which is 75mm. You can find the adapter at ZZP but you need to midify the throttle linkage which is very easy.

Hmm.. my intake is 3.5 in. would I want to go up to a 4 in. again? Or would i be able to just use a coupler and have significant air flow with the 3.5?

I wass using a 4" intake but I think I'm going down to a 3-3.5" cause the N* housing seems a little smaller and it is a little easier to route in tighter spaces. Shouldn't hurt airflow that much.

hmm they have a cheaper N* adapter plate on zzp that's 50 bucks cheaper.. do you think it would matter? and would buying that throttle cable adjustment kit be worth it or is that something like you said is easy enough to do?

And I see an ls1 TB adapter on zzp, I haven't heard of anyone here running them, but I googled the specs on them and it's saying 80mm? zzp also says you may have to modify the ls1 tb though..

I wouldn't buy the bracket. When you get your TB, I will show you where to bend and cut. You can do it with a hacksaw and pair of pliers. PM 97rivman on the LSI TB. He is running one. I heard they require a lot more modifying than the N* because of the reverse linkage. 97rivman will know. Running 80mm TB will require porting the SC housing to make a difference. Think the SC input is 77mm.

gotcha gotcha

My opinion is you don't need a bigger throttle body until you can actually use the extra air. This means modifying other parts of the engine/exhaust for more flow + programming more fuel delivery to gain power. Generally, you only need a bigger throttle body after you have upgraded to a larger intake, cam or rockers, headers + exhaust, and want to run a smaller pulley. If you can do this with zero KR, a bigger TB then makes sense, as it becomes one of the limiting factors, and should increase flow on the intake side = some more air to mix in more fuel.

I wouldn't do it early on because the TB isn't the limiting factor until you free up air flow through and out of the engine. More on engine air flow:

https://rivperformance.editboard.com/series-ii-engine-transmission-f4/why-is-engine-air-flow-important-t194.htm

well i've decided on rockers, and i'll probably be going the downpipe path rather then headers. long term I want to ditch the gen 3, and pick up a gen 5. I'm just trying to figure out what I need to save for, and in what order.

Here in the next day or so, I will post what I did and what order I did them in. I will also post next to it exactly how much it cost me. I need to get it done for the insurance company anyways.. Not saying my setup would work for what you want to do, but it would give you an idea of what's available. Hopefully we can get some other members with different setups to contribute too.

Let us know what the insurance company does to you too.

So far you're the only one I know of who has told their insurance company about their mods.

One of the great things about driving a 300 hp, 10-year-old, 2-door coupe made by Buick: dirt cheap insurance. Maybe I should call up my agent and straighten this out.

The N* needs to be from a 2000+ to fit the common TB adapter plates for a N*.

There is a considerable difference in the N* TB over the stock one. The first thing is you need to run an external MAF in front of it. Performance wise, the tip in is significantly different. By tip in I mean how quickly you open the throttle plate. An L67 follows a normal curve, the N* starts curving and is then flat. This gives you gentle low end and then a feeling of YIIIIIPPPEEEEE around 25% throttle. Lastly it will flow more air if your motor can.

I agree with Aaron on this last part. Evaluate the mods you are doing and the order you do them in. You will spend around double modding if you follow an odd order.

Suspension and brakes
Transmission
Engine

http://www.zzperformance.com/grand_prix/products1.php?id=817&catid=113
This is the new option out there. Not cheap, but mechanically it is a drop in replacement. Need to tune for the '99maf but you will be doing maf tuning for any new TB.

But that won't bplt upu to a Gen V. Thats my gripe.

oldsman105 wrote:

But that won't bplt upu to a Gen V. Thats my gripe.

No way, didnt even notice. I learned about it from a thread on clubgp and some how I got the idea it was set up for both. Add another 75bucks to its cost. Much less attractive cost wise.

I wonder if there is enough meat on it that you could drill it out for a GenV. I am sure they would rather sell an adapter.

Ofcouse if you are a chump like me, you already have a the adaptor. Im running a '97 TB on a GenV.

W00t... Gen III FTW!!!

RhinoFLA wrote:

well i've decided on rockers, and i'll probably be going the downpipe path rather then headers. long term I want to ditch the gen 3, and pick up a gen 5. I'm just trying to figure out what I need to save for, and in what order.

if you wanna get the most out of a gen V (if you go that route), you really need full headers. the N* mod wont even be necessary unless you are pretty modded, gen v or not.
in other words, if you aint going all out, you probably wont ever needs to modify your throttle body.

The billet TB seems like a waste to me. For much less one could order the full N* kit.

There is plenty to gain from opening your intake and exhaust without modding to the max. B'ville owners (I'm sure Riv's too) notice a huge gain from opening the airbox from it's restrictions.

If you add rockers or a cam and have set your mind to a Gen V, you would automatically need headers. While doing the Gen V, why restrict it's intake?