RPM2 Manifold for AU3 XR8

[inventiv]

G'day, I'm thinking of getting one of these for the AU3 XR8. Apparently quite good gains are to be had. The manifold is off right now so I thought I'd take the plunge.

Here is a link to the manifold:
http://www.summitracing.com/int/part...view/make/ford

And the spacer I'll get to avoid heat soak:
http://www.summitracing.com/int/part...view/make/ford

Can someone with experience with these please clarify the following:

1. It fits on a 220 XR8 Windsor, correct? lol

2. Besides the spacer and manifold, is there anything else required?

3. Edelbrock is recommending also getting their 70mm throttle body - is it necessary? Big gains over our stock tb?

4. There's an adapter for these manifolds but I'm unsure if it's required:
http://www.summitracing.com/int/part...illocation=int
Any thoughts?

5. Will it fit under the stock bonnet? Looks taller than stock? If not will the fiberglass bulge bonnet fit it?

Looking for advice from anyone who has experience with these.

Cheers

[BOTTLEDUP]

First up are there any other mods to your AU3 (I'm presuming its a 220kw)?

The RPM2 is an excellent manifold if you are chasing a bit more top end power, but it will come at the expense of power & torque below 4500rpm.

If your engine is stock I'd question whether the change is justified, but to answer your questions:

1) Part number of the manifold you want is EDL-7123. On our Falcons the upper intake bolts on the other way around to US engines, so the writing will be upside down.
2) I would not recommend the 0.500" spacer, I believe you will have bonnet clearave issues. Use the 3/8" spacer from Trickflow if you feel you must run one, I have one on my engine and I'm not convinced that it does anything to reduce heatsoak.
3) If you have a 220kw XR8 you will already have a 70mm throttlebody, identifiable by the Tickford logo etched into the front face. Use this TB over any aftermarket options out there.
4) You do not need that adaptor, is it a Mustang part.
5) I doubt it will fit with a 0.500" spacer. You could run a fibreglass bonnet to gain more clearance or lose the spacer.

Hope this is of some assistance!

[inventiv]

Thanks for the feedback, that's a great help.

The car has several mods and is currently getting the top-end rebuilt so I thought it's a good time for this.

Wonder if I can get that writing ground off then, so that it's not weird looking.

Looks like the spacer may be a waste of money then. Why do you feel that the spacer isn't helping? Haven't noticed any difference?

[MrEL]

We looked at putting my old RPM II on a mates motor when we were doing his engine change on his TE50.
Not a hope in hell that it will clear the bonnet and his is the Fairmont style bonnet which is a bit flatter giving a bit more clearance.

[inventiv]

So won't clear an XR8 bonnet then?

[inventiv]

I'm having a bit of a rethink here...

The stock AU3 220 XR8 intake is a GT40 intake manifold right?

Judging by these results, it's actually ideal for what I want - low-end grunt:

http://www.mustangandfords.com/how-t...manifold-test/

Looks like the RPM2 manifold is only really useful at sky-high rpm. I'm not after that, looking for street driven usable power.

Can someone confirm if the XR8 220's have a GT40 manifold?

[Sox]

No AU's had a GT40 inlet.
All AU V8's have the Explorer inlet, which also has very good power down low and mid range.

[BOTTLEDUP]

As Sox has said, the true GT40 intake is the tubular upper used on the EL GT. The AU V8 got the Explorer manifold, and the 220kw had some minor port matching and a clean up to suit the larger 70mm throttlebody.

It remains the best manifold option for anyone chasing torque & throttle response up to 4500-5000rpm.

[inventiv]

Ah ok, well I'll save the pennies then. I want it to be good down low as it's a street car only.

[Bossxr8]

If you want to improve it, the Explorer lower manifold's respond very well to porting.

[inventiv]

Is there a lot to do when porting these?

[Bossxr8]

Most of the work is in straightening the front and back runners. There are porting guides available for these, but it needs to be properly, not just hogged out and bigger is better.