Xu9J4 Throttle Fit Xu9J2 Manifold?

[sonic_az 0]

Hi, does anyone know if the mi16 throttle can fit my xu9j2 manifold and am I going to get any improvement by fitting it? :P

[Anthony 1,000]

It should fit (it does fit the other way around) but I strongly suspect you won't see any performance improvement on a standard-ish XU9J2 engine. Also, most XU9J4 throttle bodies are worn these days (although XU9J2 ones are probably no better)

[sonic_az 0]

kool, any suggestion what kind of mods that can make a different when I fit the mi 16 throttle? :D

[DrSarty 90 1 Cars]

I doubt you'll get any noticeable difference in just changing a single throttle body; unless it's just changing a bad one for a good one.

 

Might get a different noise, and 'feel' faster, but otherwise not an exercise to yield anything noticeable IMO.

 

A different (read: bigger) throttle body would need to work in conjunction with any or all of the following:

> new cam(s)*

> new exhaust system (with or without new manifold, but more with a new manifold)

> new injectors*

> forced induction or other major engine mods, (pistons, displacement etc)*

 

* on 3 of the above would most likely also need a mappable ECU and tuning.

 

The best summary is, a simple/cheap/easy modification is not going to give you much, i.e., the amount of change or improvement will be directly proportional to the amount of money you spend.

 

Routes to changes or improvements that'll make a noticeable, real-world difference are:

~ stay 8valve, change exhaust - perhaps up to 10bhp gain (air filter and body changes might add a little more)

~ stay 8valve, follow route for throttle bodies (circa £1,500 minimum) - perhaps up to 20-50bhp gain

~ stay 8valve, go forced induction (super or turbo charge) - perhaps up to 100bhp gain

~ go 16v - perhaps 30-50bhp gain

~ go 16v with throttle bodies or forced induction - perhaps up to 100-200bhp gain

....all with associated costs from £300 to £3,000 plus.

 

And a final word is that like gaining top speed, it gets more expensive, more difficult to get more and more.

Edited October 13, 2014 by DrSarty