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dan, about the decat downpipe & straight through centre section we were talking about lastnight on msn...

the downpipe i will be sending you is from a 1.3 spi. is there any differences between the bore of the pipework for a 1.3 spi & a GT?

reason i ask is... im putting a GT engine in a 1.3 spi body & want to know if the current spi exhaust is of a smaller bore diameter.

another question is... what is the largest size bore pipework suitable for use with a GT engine? i understand this could mean changing the entire exhaust system to suit (so be it if needed).

i dont know the current bore diameter of my existing 1.3 spi exhaust, sorry

i want something meaty & thst will flow well when i add ahot cam, & possibly dump the injection & opt for some twin 40's or similar (just an idea @ the moment).

ps. i'm sending 2 downpipes for 2 decat pipes plz (one for a friend with a 1.3 spi genesis).

cheers

The GT and SPI CL downpipes are identical, so there's no problems there. From the CAT back a standard GT has a slightly larger bore exhaust system than a standard CL - I can't tell you the sizes off the top of my head though, sorry.

On a GT I wouldn't go any larger than 2" (stock G40 exhaust is 1" 3/4 ish if memory serves, and you don't gain a great deal from just an exhaust on a stock G40) so 2" should be plenty for even the most highly tuned GT.

Whats your g40 exhaust diametor andy?

I gotta get a new zorst sick of mine dragging along on the floor..i want 12" round pipe with a 50" tailpipe..ya know nothing too barry

The downpipe has been modded so the single pipe part is now 2" diameter, the system is 2.25" with a mildly Barry 2.5" straight-cut tailpipe.

Like Andy said, the downpipe pipework is the same size on them.

It changes from the downpipe join of the centre section, i think (depending on what system) a standard CL one is 1 5/8" and standard GT is 1 3/4". All this can vary between different brands of pattern exhausts, so I can't tell if your backbox will accpet the 1 3/4" middle section.

I do a 1 3/4" as standard with the option of 2" for a GT, which may be worthwhile if you are highly tuning it. You will need to change the backbox to accept the 2" pipework. Having said that 1 3/4" should be fine really.

amstrange1 wrote:The downpipe has been modded so the single pipe part is now 2" diameter, the system is 2.25" with a mildly Barry 2.5" straight-cut tailpipe.

Mildly barry?

Not barry, just Andy thinks anything that looks other than stock or hidden is !

Hey Gareth, You still havent sorted me some pictures out yet

Tis mildly Barry as it's blantantly not OEM... Lol. Wasn't stealth enough to escape attention from the filth. If I could've had a CL peashooter on there without restricting power I would've done, trust me! Gone a little bit OEM crazy, hence the RAs being for sale - steelies are required.

I have just aquired a stainless steel backbox off a mk1 golf...how much *guestimate* would it cost to have it fitted to my car..inc straight through pipe from decat? would need new hangers making *on the car* too.

Would probably cost about the same as a whole system really. As it's just the same amount of work (maybe more) to get it to fit. Plus it's not gonne be as good as one specifically made for yours.

I've edited the name of the thread so that MK3 owners know what it's about, rather than thinking it's just an FAO post.

It will help them find info if they were searching

Hope you don't mind!

Good idea toxxin

i don't mind @ all

i didn't know it would develop into a good disscusion