-Rudy-

Can't tune with the SAFC.

We've discussed this.

WhiteSCXJ8

sooo easy hmmmm.... Grip lets see your XJ build pics then.... ?

auburn_XJ

Turbo activates at the tip of your power band and the 4.0 is at 2000ish rpm correct me if I'm wrong, and the super is at initial shift to get you to peak power so, u got quicker power of a super, or stronger short term of a Turbo, I'd leave it stock though, my 2¢

-Rudy-

The turbo will kick in depending on exhaust flow and the size of the turbo itself. Some will spool faster by design, such as the ball-bearing models. The bigger the turbo, the longer it takes to spool in most cases, however there are exceptions to the rule.

A turbo will usually hit full boost, then push power until you get towards the top at which point the design comes into play and will either keep pulling or sputter off. Generally, if you want fast spool, you will use a turbo that usually won't pull all the way to redline. This may or may not be a bad thing. The dyno graphs usually look like the typical but then jump through the roof once the turbo spools.

Superchargers are usually RPM dependent. Meaning the higher you rev, the higher you're boosting. If you don't rev, you don't boost. This depends on what kind and the design also. Centrifugal superchargers (vortechs) are this kind of supercharger and when you look at the power-curve it looks just like a stock motor with more power due to the design and nature of the blower.

ClaytonXJ

I know right. Guess if I had some money laying around it would be fun to do. In a 2wd 2 door. You could make it pretty light. Chop the top. Forged stroker, decent size turbo, about 20 lbs, standalone, meth, built AW4 with a converter, 8.8 rear, slicks. Be cool to make 500 to the tires and cruise it around with no doors.

leecarr

Only thing I was thinking is will the rest of the drive train handle the extra gaff? With that extra power there you know you're going to use it.

Boostwerks.com

Don't worry. I've managed to develop a thick skin for haterweb bashing. Everyone has an opinion and has the deep desire to share it even if they have no meat to back it up.

We went with a log design for several reasons...

1. Durability. When you develop a product to last, this is going to be your first concern. With the fact that even the best aftermarket 4.0L headers have a nasty habit of cracking, we wanted the manifold to be bullet proof and last as long as the rig.

2. Repeatability. We could make a tubular manifold that locates it in a different location, but the most available room is under the manifold.

3. Power output. If you have ever seen the flow numbers of the 4.0L head, you will realize you don't need the top end advantages that a tubular manifold and well built collector can offer. Sure if your looking for that last 10hp for your 4.0L drag car, a tubular should be in your sights. However, for a mild street setup a pressure log manifold is perfectly fine. The 4.0L is a low compression, low overlap, low RPM engine. Simply put, the advantages of a log manifold simply outweigh the negligable gains that would be realized by going to a tubular design.

We are one of the few who have actually turbocharged this engine so don't take our "opinion" lightly. Keep in mind, we make plenty of tubular manifolds and would have built one for our rig if we felt it was the best way to go.

Our 320whp 1900lb Time Attack CRX:

CobraMarty

Boostwerks-
Is there a turbo with an internal wastegate that will fit in the location when using your log manifold? Sure there will be a comprimise, but really looking for a manifold that can use an internal wastegate turbo. Thanks.

Boostwerks.com

As far as an OEM turbo, I have no idea but I'm sure there is something out there that would work.

I would reccomend an internal gate Garrett T3/T4 with a cosworth style turbine housing from ATP turbo. They have a clockable WG bracket that would allow you to get the compressor housing and actuator where it needs to be. My only other concern is that internal gate turbos typically have a longer turbine outlet, which may reduce your ability to fit the downpipe. There isn't much room between the turbo and the firewall, but by going to an external gate and 3" V band outlet turbo, we we're able to fit a full 3" mandrel bend downpipe. If however, you are dead set on going with an internal gate, we can build you a manifold without the external flange with a discount as well.

http://www.atpturbo.com/mm5/merchant...egory_Code=TBN

Pics of our setup...





Hugs tight to the block but doesn't touch




Recirculated dumptube




Heat control








Enjoi

Boostwerks.com

Everyone likes a video...

8lbs of boost, 33"s, stock 3.55 gears, stock aw4...

jblack'00xj

Hey man, if thats a vid link, idt it worked.

I'll help ya out though,
http://www.naxja.org/forum/showthrea...031285&page=10

Page 10 fellas, if you dont want to read through the amazing thread!

Well done my friend. I feel that once taxes come back and I recover from the holidays, you and I will be in touch.

CobraMarty

I see you use the Brown Dog motor mounts, maybe they can make a mount that bolts to the engine and moves the mount forward 3" so there is more room for the intake tube so you don't need to use that accordion intake hose and move the turbo forward an inch or so to give more clearance for the downtube.

http://browndogindustries.com/s2572-...cketspair.aspx