Thread: Aftermarket TD5 exhaust manifolds

Must ask them what these specs are...not provided with the gear when it arrived, nor is it on their website. I'll post back here for future reference.

Are the bolt/stud holes in TD5 manifold all the same or are they staggered?

e.g. a 4BD1T uses M10 studs (or bolts) for all manifold fixings, but the centre holes are ~10.5 mm and they get larger as they go out - meaning the end ones are 12-13 mm.
http://i124.photobucket.com/albums/p...psdf741196.jpg


This means that the manifold can expand and contract without breaking things or leaking...

I contacted JE Engineering today, their response "The process we use is to re-face (flatten out) the original manifold and then fit to the head using a genuine gasket and our stud/spacer set. Our stud and spacer kit allows the manifold to expand and contract with each cycle therefore reducing the potential to warp the manifold. We have had lots of success with this simple kit".


Still don't get it really, how can a spacer allow anything to expand and contract if its done up tight? Doesn't sound like they de-web or coat the manifolds.

Originally Posted by Islandnomad

I contacted JE Engineering today, their response "The process we use is to re-face (flatten out) the original manifold and then fit to the head using a genuine gasket and our stud/spacer set. Our stud and spacer kit allows the manifold to expand and contract with each cycle therefore reducing the potential to warp the manifold. We have had lots of success with this simple kit".


Still don't get it really, how can a spacer allow anything to expand and contract if its done up tight? Doesn't sound like they de-web or coat the manifolds.

"Done up tight" may not be done up right. Tight enough to allow expansion and contraction?

The spacer will have different thermal properties for expansion...
Just as the alloy head and cast manifold do.

Originally Posted by Tombie

The spacer will have different thermal properties for expansion...
Just as the alloy head and cast manifold do.

Coefficients of thermal expansion

Product Coefficient (10-6 m/m K) *)

Aluminum 22.2
Cast Iron Gray 10.8
Iron, forged 11.3
Steel 12.0
Steel Stainless Austenitic (304) 17.3
Steel Stainless Austenitic (310) 14.4
Steel Stainless Austenitic (316) 16.0
Steel Stainless Ferritic (410) 9.9

I'm soon getting DPL a to put a bigger turbo and sports manifold in my D2 will see how that goes

Until JE Engineering come back to me with their suggested torque, I found this reference from a UK site:

M6 would be from 4.1Nm to 19.1Nm, M8 would be from 9.8Nm to 46.1Nm. Assuming 8.8, then it would be 10.9Nm or 26.1Nm. (M10 would be 55Nm)

I don't have the studs with me to measure what they are. IIRC they're M8.

And also that RAVE/Workshop manual notes that stock exhaust manifold studs are tightened to 25Nm.

I'd be keen to hear how that DPL manifold looks too.