SLR Throttle Body?

Has anyone tried the SLR bored throttle body? If so, did it give any performance improvements? Any reasons against installing it?

Thanks!

I called SLR a while back to order one and they don't recommend using it without thier cams. I guess that you would take in so much air, that the motor wouldn't know what to do with it...

Isn't air amount passing through the intake dictated by vacuum (on a N/A Xterra)?

It might have been a nice way to say buy the whole kit...

Seriously, it probably wouldn't affect much - as the cam specs (stock) are not great enough to generate enough flow demand. When the engineers design throttle bodies they calculate intake flow and determine the size that is the least restriction for the horsepower they desire. Too much throttle volume causes no benefit so they stop at the optimum.

It's like guys that put 700cfm (rated) carbs on stock 5.0 ford engines. The engine cannot make enough vacuum to flow 700, so you gain nothing. With the correct carb the vehicle runs better, has a better vacuum signal at part throttle and burns less fuel.

Though the X is EFI, the air flow dynamics are the same...the bigger throttle plate itself is probably only 5hp. With the better breathing of the cams, intake, ehxaust - if you were to do the thorttle body last you would probably see 20hp gain.

So, even if I have an intake and exhaust, it probably wouldn't do anything without cams...

Well, not as much as it could with cams...

You are probably a little further ahead than most, you have dual exhaust and an aftermarket intake. Still if you think about intake pulses and manifold loading your smallish valve lift and duration is hurting the most. It might give you a little boost, but nothing drastic. As it stands you have allieviated a couple of the many intake/exhaust restrictions.

Just as an FYI, a small block Ford that I am building started with a 400cfm 2Bbl carb stock - 160 Hp. Here is what I have changed to make 600cfm necessary:

Higher compression ratio - 8.6 to 9.2
Bigger valves - 1.5" int, 1.3"exh - 1.7", 1.5"
Full Port, polish, bowls and combustion chambers
Bigger cam (492 lift, 268 duration)
Headers (full-length) to dual 2.5" exhaust
Intake manifold (to accomodate) and 4Bbl carb.

As it stands finished ~250 hp.
If It were carb only ~ 180 hp.

Do it if you want (I have seen your truck with 35's - I am sure you need the power too), but I will make more of an effect if you can scrape together more clams and buy the cams too.

I wish it were the case, but I think you have the wrong guy!!

You're confusing Strom with Stormy. Stormy's got the 35" tires.

I guess that's what happens when you get addicted to the pipe....

Sorry Strom!

Anyone know the emissions laws in Texas regarding cams and such?

This page was updated 21/oct/2002...current, and regarding Texas emissions testing and guidelines.

They\'re cracking down!

Cracking down from where they are now probably means that they require you to use cats.

Seriously, though, are they just running an OBD-II test and then a tailpipe test to see if you pass. I would think that mild cams should pass. I have to look into this more...

Being originally from California, I never thought I would be able to use cams or anything that wasn't CARB certified.

Found something:

Ian, didn't you have your emissions tested pretty recently? What were your stats on this stuff? Does your X have the two cats setup or four cats?

Yes I did. I'm going from memory, but my readings were very low with the K&N intake and CALMINI exhaust.

I have 2000MY, non-coastal Xterra, so I only have the 2 cats.