Thread: 3.9 V8i intake manifold

This is a Thor manifold (with gas injection fitted).
http://www.aulro.com/afvb/attachment...injection1.jpg

Thats the lower part of a thor - not much good without the rest though.

It seems like a lot of work changing manifolds to be left with the same throttle body
I would just fit one of these and be done with it


TI028 Carbon fibre plenum 71mm - £495.00 : ACT Performance Products Ltd, - your source for TVR upgrades, components and performance accessories.

I sometimes get boondoggled how threads about increasing low down power get hijacked into threads about increasing horsepower when it is quite obvious that the manifolds shown are for high end power in sports cars not low end torque in 4WDs.

The manifold shown in jakeslouw post is NOT a thor. The manifold shown by bee utey IS a Thor.

They are completely different to the old breadbox manifold and have a different throttle body.

BTW , if you have an enormous throttle body , then they become more difficult to drive off road. Even my Thor is very sensitive to small throttle movements.
Regards Philip A

Originally Posted by 400HPONGAS

You never know Hardchina , you might want to see the worth of $200 plus set of plugs . As for your tuned length mythology , every manifold ever made is a Tuned length , the more you tune it , the less the Torque spread . its all a compromise in the Long run . Helmholz theory is fine is you want a 500RPM power band .Pray tell , when you changed the manifold did you change the Throttle body and Plenum design as well ?

Mate I just swapped the whole lot from a 4.6 - didn't change the plenum or throttle body designs. I reckon the BMW engineers know more about it than i do.

500 rpm power band.... nope - are you just making stuff up now?
That might be the figure on paper where they are doing their thing 100% but my pants tell me they work well right through the rev range required for a daily driver.


$200 set of plugs, ??? i just use the cheap ones @ $25 a set

What manifold to you recomend for the 3.5? and will it give me peak torque at cruising revs (~2600 - 3000rpm)?

So , Hardchina , you didnt change just the inlet manifold , infact you probably changed the Throttle body , the Plenum and possibly the injectors as well , so which parts made what difference ? You honestly think any BMW engineer would have anything to do with that motor ? What this 4.6 ?
The final version, used in the Range Rover, produced 222 hp (166 kW) at 4750 rpm and 300 ft·lbf (407 N·m) at 2600 rpm.

Now what manifold would I use ? A edelbrock or Offenhauser single plain 4 barrel with 1000cfm progressive throttle body on it ,Something Like this , but thats a 600CFM Quad throttle body for Straight LPG

HAHAHAHA!
apples and oranges mate, for starters that is a holden v8, minimum capacity 4.9/5.0L, in (who would have thought) a holden!!!
single plane manifold, yeah perfect for driveability and bringing the torque band lower, nice one!

in hardchina's case the plenum made the difference, due to longer intake runners, it is a proven method of shifting the torque band, similar thing done from factory in the EL falcon, people swap the intake from them onto earlier 6's and also find a torque band shift lower in the rev range

Originally Posted by 400HPONGAS

So , Hardchina , you didnt change just the inlet manifold , infact you probably changed the Throttle body , the Plenum and possibly the injectors as well , so which parts made what difference ? You honestly think any BMW engineer would have anything to do with that motor ? What this 4.6 ?
The final version, used in the Range Rover, produced 222 hp (166 kW) at 4750 rpm and 300 ft·lbf (407 N·m) at 2600 rpm.

Now what manifold would I use ? A edelbrock or Offenhauser single plain 4 barrel with 1000cfm progressive throttle body on it ,Something Like this , but thats a 600CFM Quad throttle body for Straight LPG

Cool, 300ftlb at 2600 rpm - I'd be happy with that. Pretty much what i need and want. Max torque at hwy cruise = max drivability and max economy.

Changed up from the standard 3.5 carb manifold to the Thor. only change with the gas side is a Ford EF / EL? mixer from the wreckers.

Straight gas before, straight gas now.