What about resizing the pre-cat?

[Hegg]

So, as I was thinking about the pre-cat "mod" where you take it and hollow it out, and because I'd also like to get the PECO 2.25" system, I was wondering if it's reasonable to enlarge the pre-cat exit diameter to 2.25 as well?

Since my dad's a machinist and has the equipment to do it, would it make sense to enlarge it? Or would that just weaken the pre-cat or something?

[Dave M]

I forget what the pre-cat looked like and am not sure there was enough material to take another .25" out of. You wouldn't want to create a weak spot for cracks to develop in the system. That said, it sure would be an easy way do adapt to the 2.25" system if you can mate up the flanges.

[Doug]

hey, let the machinist bore it out and put some weld on the outside to reinforce it and it could perhaps be done. should it break then you just make a replacement pipe like the stiffy for it. Or just get a stiffy in the first place?

[Enright]

Hegg,

Having messed about at great length in that particular area (see my contribution to the Stiffy thread) I'm sure that you would be fine to enlarge the hole to 2.25".
After all, it's only 0.125" bigger in diameter, and there's easily enough material in the mating flange to do it.

But it's a bugger to get off, and if you're going to do it, then you absolutely MUST take advantage of the opportunity to port the wastegate on the turbo. You're going to have one of the free-est flowing systems around and are almost guaranteed to get boost creep if you don't.

[Hegg]

Alright, now I feel like I'm getting in over my head! Like I've said, I'm new to exhaust, and especially to turbo, so I don't know what to do as far as the wastegate goes. Where is it, how do I port it, does it need to come off, etc?

But please realize, I REALLY appreciate the suggestions! I'd love to have a free-flowing system, and would like it even more if the PECO system was available for the catalyst cars!

Is there a good guide on porting the wastegate (or even what the wastegate does)?

[Doug]

Is there a good guide on porting the wastegate (or even what the wastegate does)?

you're in luck as there is a recent thread with help and pictures on this. This is something your "machinist" can also easily do for you! The problem is deciding who is the fool to be the one to get the part off the Elan to do it!!

[Enright]

Well put Doug! Heat will almost certainly be required.
If you're not sure, get the mechanic to do it and just pay the money.
Sheared bolts aint fun.

Hang on a moment and I'll find and post a link to the thread...

[Hegg]

Yeah, as far as getting parts of goes..... it's hard.

We had it up at the shop today and spent 30 minutes just trying to get the heat shield off the pre-cat, with no luck. Try again later I suppose.

And I just ordered my new windshield - ouch, thems are s'pensive.

[Enright]

My guess is that you're just going to have to put up with sheared heatshield bolts and then drill them out later. You can't heat them up and it's almost impossible to get penetrating oil into them.

Doc Fizzix managed it without knackering any, but he's just too sodding talented for his own good!

Anyway, look from where I get involved on this page and you'll see how it went for me.

[Hegg]

Oh, the bolts came off slick as a whistle. There's just no way to get the heat shield out of the car because there's not enough clearance! The anti-roll bar and stuff are all in the way.

[Enright]

Eh? It comes off in about 4 or 5 pieces. You must have missed a bolt or two. As one part comes off, it reveals more bolts to remove the next.

The lower one does need a bit of wiggling to get it past stuff like the anti-roll bar, but it shouldn't be a problem.

Put it this way, it's nothing compared to trying to get the pre-cat past the A/C compressor which is a real git!

Oh, and I really suggest NOT running the car without any of the heatshields - they really are there for a reason. I've heard horror stories of melted bonnets, and you especially don't want to fry A/C pipes.

[Hegg]

Ok, I see what you're saying -- I just had the lower piece unbolted and was hoping I could get it around stuff.

Yeah, I don't think I'll drive without it though!

Thanks for the advice once again.

[Enright]

Nope, if I remember rightly you need to start from the top and then the front and side, and work your way downwards.

Ooer missus!