Having been very happy with my 2Bular GT3 exhaust and de-cat I’ve decided to take the plunge with Jim’s latest 2Bular 4-1 manifold creation. He’s made the new design shorter, lighter and has eased the bend angles so there is more clearance from boot area. Jim and many owners have already seen decent gains on his previous design so I’m expecting to see some decent figures.
It will be booked in at Essex Autosport shortly for a baseline dyno, fitting, custom map and then post dyno. My current GT3/decat setup sounds amazing so can’t wait to hear what this sounds like (also hoping for more flames)
Will keep you posted, until then please drool over these photos:
When you fit the manifold you have to remove the heat shielding from it, this seemed the best way of putting the shielding back, I really didn’t want to set the car on fire
For a mid-engined install, it has an incredible amount of space around the exhaust/cyl head area. Far more than say, a Honda or Duratec conversion. I understand the concerns but I have more customers running with no coating/wrapping on the 4-1 than i do with.
As has been noted, I’m bringing out a Titanium version of this 4-1. Normally, I wouldn’t consider it. If anything, it would be in Inconel - far more reliable. I brought this design even further away from the boot/trunk area precisely because I don’t want a Ti 4-1 customer thinking he has to cover it up with anything. If you’re worried about heat build-up in the engine/exhaust bay, get rid of the Cat - if you don’t want to do that, at least get rid of the heat-shielding behind the rear grilles. This will help extraction.
Jim, going back to your inconel comments. I have heard differing things about it. Yes its light, yes it deals with heat well and doesn’t expand as much as stainless etc. But I have heard it also work hardens at a very fast rate and this can lead to cracks and all sorts of dramas after many heat cycles. What are your thoughts.
I’m with Jim on this, save your pennies on the heat wrap or coating whilst at the same time binning the restrictive Cat and grills at the back.
Do this and you’ll save money, save weight (my Cat and grills weighed soo much) plus get the cooling you’re after.
I know what you mean about Jim’s manifolds…you almost want to hang it on the wall rather than get it grubby hanging off the side of your engine. I remember when mine was shiney and gorgeous.
Heh Sean, well as usual - it all depends! I see posts on other forums stating that Inconel headers on an F1 car only last 3 or 4 (or whatever) races. Given those stresses, they may be correct! I would suggest if you choose a suitable wall-thickness - say 0.8mm-1mm - (still lighter than st/st)and pay heed to its working environment, an Inconel manifold would be fine on the 2zz-ge installs. If you’ve heard of work-hardening, there may be too much engine/transmission movement which will stress any manifold. I believe the McLaren F1 V-12 manifolds were 0.8mm Inconel? Has there been problems with them - be good if anyone knows.
Titanium has the bling factor in the automotive world and demand for exhausts in this material is increasing. It is extremely tough, as well as being light of course.
I should point out, my last job in the oil industry before starting this business full-time was a 12"dia Titanium drain line for an off-shore laundry.
