nmp0098

So, I was pulling nearly a pound of vacuum at WOT and I had already ported my stock throttle body to the point of worthlessness. In fact, it started setting codes at idle and controllability was completely shot... lesson learned on how much and where to port a throttle body for a good idle. Anyway, I looked at LS2/3 throttle bodies and larger intake necks, but I started adding things up and it was getting close a FAST102. I then scored a Nick Williams 102mm throttle body for cheap, and the race was on. Several feet of tubing, a new coupler, a power steering pump, some catch cans, and a pack of JB weld later I had the intake mounted up.

The power steering pump is the biggest obstacle to the swap, so I had to notch the FAST 102 and move the power steering pump inlet to make clearance. I didn't actually take much area from the plenum and didn't have to touch the runner for cylinder 7 (2 in our cars) except for a little clearancing on the outside. I'm not sure how the guts of the aluminum-cased power steering pump will handle the excess heat from welding, so I started with JB Weld. The JB Weld is holding fine, but I plan to modify the original pump now that I made the replacement fit and do a better job of fixturing the inlet.

One thing that really surprised me was how much port matching I had to do to get the manifolds outlets to line up with the runners on the heads. I don't know how much is due to the reverse mounting, but that isn't supposed to make a difference (the heads themselves are switchable).

The car is nice and snappy with the new parts, and runs the new throttle body and everything else with no codes. The MAF tune for the 2008 Z06 formed a reasonable starting point for tuning and has the correct IAT tables.

Here's the job nearly done:


The stock and NW102 throttle bodies:


I got tricky and left the harness compatable with both throttle bodies:


When I went to the LS3 valley cover during my head swap and DOD delete, I accidently cut the OPSU bung at 30* instead of 15*, so I had a 60* angle which conveniently left room for the throttle neck.


Even so, I had to grind a good bit of the material in the throttle neck for clearance, so I backed it with a steel plate held on with JB Weld:


This is a test fit of the trouble area:


I even had to clearance the water pump manifold a little bit:


I was careful and found that the cylinder 7/2 runner didn't have to be modified other than removing the part that would screw into the support I removed. I'm attaching on my steel patch in this shot:


The power steering resevoir is just sitting there, and it's higher than it was, but everything did fit (including the PCV tube from the LS3 valley cover that I've been using since the head swap):


I used 4" aluminum piping (96mm ID) for inlet tract. I used an LS7 style slot MAF and a saxonpc.com airflow straightener in the pipe:


At the RPM's I spin the engine (plus the extra power) I get a lot of oil blow-by, so a pair of ebay cheapie catch cans got thrown into service:


And here is it mostly wrapped up. I'll shoot a final photo sometime soon:

91parkave

iTrader: (4)

holy ****!!!!!
I know its to late now but have you thought about using a toyota mr2 electric power steering pump? and btw how much did the MAF end up running? im assumig the z06 maf would be closest to our hi/lo maf table setup so it would be a copy paste affair and then maf tune from there right?

Sadden

Congratulations man. that looks ******* sick.

DavidGXP

iTrader: (14)

So here I am sitting with my girlfriend at red Robin waiting for food. She is pissed cause I am glued to my phone...
Holy mother of God Nate!!

higsy

Hoooolllyyyy shiz. Nice job, can't wait to hear it run. Is hood clearance an issue ?? Doesn't look like it from the pics

x11 nut

iTrader: (3)

It's purdy!

neilownz

Nice. I saw the new black fast lsx 92 manifold in a catalog the other day.

1CL3ANSUP3RSPORT

iTrader: (23)

Wow never thought I would see this,can't wait to see the results! Congrats

94ss06gxp

iTrader: (5)

didnt know you were still going with the gxp, that thing has to rip for being an ls4

MillerMonteSS

Damn... That looks good.

Brian396

iTrader: (3)

What a thing of beauty! Do you hear angels sing when you pop your hood?

supercatxr7

iTrader: (5)

How close is the bottom of the throttle body to the header crossover pipe? How much gap between the two?

nmp0098

Thanks guys! I still have to improve the way a couple things are mounted, and I plan to swap in a MIG'd power steering pump. I also can't get the rear header collector to downpipe connection to properly seal anymore, so I need to get in there and weld it up or something.

There's plenty of hood clearance. The FAST is barely taller than the LS6 at its highest point, and the fuel rail is basically a stock LS1/6 from a height standpoint. Plus, I'm not using the engine cover.

I think the 78/90/92 manifolds are basically the same runner design, but the 102 is revised for a bit more power. Plus, the 102 is actually cheaper than the 92 from what I saw.

Well, my header crossover is custom to clear the intake neck... the DT headers run higher than the stock manifolds. But, the pinch point is under the silicone coupler and I have over an inch of clearance between the bulge in the coupler and the header wrap.

Haha, my exhaust leak isn't that bad...

DavidGXP

iTrader: (14)

Keep up the good work. It has been a long time since I have gotten excited about a build. I can't wait for some dyno/track times. MPH will be a true indication of HP since I am sure you need a looser converter and more gear.

I have pondered the thought of using a LSXRT 102mm intake with a modified hood since Brian396 was trying to adapt a truck manifold to his GXP. The power steering pump has me a little concerned though.... I really wish GM used an electric pump!

Here is some good reading material:
http://www.enginelabs.com/engine/tec...ake-manifolds/

http://www.autotraderclassics.com/ca...ke-75465.xhtml

A few questions for you. Please examine the pictures

Is this bulge on the LSXRT much different then the LSXR?
LSXR



LSXRT


I would have to extend the wiring harness, and cut the hood, so I think I will stick with the LS6 intake and spray away. HMM...........

higsy

I have to agree David, I haven't been this excited since the Dt headers were first being discussed. Not many mods for this car but this one has got me thinking again. Damn u.I don't want to have to spend more money. My gxp is laid up till I get my TEP
Anyway great looking build. When u get it finished are you going to post any videos ? What are your expectations ?

fieroguru

iTrader: (1)

Looks great! curious as to how much it improves the upper RPM power.

91parkave

iTrader: (4)

@davidgxp GM did use electric pumps the g6's have them as well as the new camaros and other late model gm cars do. The easiest ive seen so far is to use the toyota mr2. if you search on ls1 tech you can find some of the retrofits and in our case i tink that will free up most of the room you will need to mount any intake manifold

nmp0098

Well, the power steering pump is iron, not aluminum. It always helps to check with a magnet before you get all worried about aluminum and how quickly it dissapates heat.

It's hard to say looking at the pictures, but it does appear to be similar. You can always make more room behind the manifold, but the critical part is clearing the pump. If you have parts laying around, you can measure on the LS6 manifold. If you look at your setup now, it just clears the pump. I wouldn't cut the hood for whatever you gain with an LSXrt over and LSXr, but go crazy with it if you want.

I'll get videos posted and all of the rest. I'm hoping that Milan is actually open the last weekend so I can run this year. I'm busy this weekend and I still have some odds and ends to tie up before I consider the car track ready. The exhaust leak needs to be cleared up before I can truly trust my O2 sensors. I ran 13.1 with stock heads, lifters and the LS6 intake manifold, so breaking into the 12s on street tires seems reasonable.

I think it helped everywhere, really. The runner length is still tuned for torque, but the extra plenum volume, larger throttle body, and port matching helps the top end. I won't even speculate on seat of the pants, because I drive my E350 cargo van when the car is down and everything feels fast after that.

Just an FYI for you, but I found evidence of float and PTV contact in all of the cylinders with DOD lifters. I haven't checked on your build thread in forever, but did you get that Fiero wrapped up yet?

Almost everything late model has electric power steering, but that's different than an electric pump for hydraulic power steering. Electric power steering uses an electric motor to provide assist, and saves gas because it's only a load when turning. However you look at it though, an electric power steering pump could be located anywhere to make room for a centrifugal supercharger.

DavidGXP

iTrader: (14)

Thanks for the updates!

fieroguru

iTrader: (1)

The Fiero is getting closer every day (now that I am actually back working on it). Have most of the wiring done, just need one last test fit to finish the harness and fuel/coolant plumbing, then it will be just the finishing touches.

Thanks for the heads up on the PTV issue. Guess I will take it easy and set the rev limiter to 6500 to start with, but depending on where the cam peaks with its current installed position, I might just have to bump it up.

Never have pulled the heads of an LS engine, so not sure if I could run a rev kit (springs between the bottom of the head and the outer housing of the lifter) to help keep them under control without further loading the internals of the lifter.