rr placement

[Chris and Alana]

hi guys. I recently fitted a nur spec r and first decat and Im overboosting to 18 psi. I have a 2" rr but can I put it in the first joint from the blitz back box? thats the joint on the bit of pipe from the back box. or does it have to be further back. thanks. Also is it ok to have a rr fitted when the second cat is still in and does a rr change the sound of the exhaust. I know theres alot of questions but I need this sorted. Thanks for the help guys

[Chris and Alana]

anyone :( Im off work today and have all the bits to put the rr in but im just not sure about the above.

[squiffy]

i had my rr inbetween the decats mate

[Chris and Alana]

I know the most common place to put it is just after the second cat or decat but does it matter where it goes? a restriction is a restriction isnt it . . . . . and I thought the further away from the engine the better so I thought I would put it in the next joint back (between the back box and the mid section of the blitz exhaust) plus I didnt want it just after the second cat as it may cause more heat build up within the cat itself..... oh im confused. all I want to do is bring my boost down to about 1 - 1.1 bar without stupid EGT's :(

[merckx]

I've put mine after the second decat .

But any location will do. :)

[Chris and Alana]

right iv just fitted my 2" rr but when I got under the car evey exhaust joint I payed someone to do was leaking so I had to undo them all a paste them up and put them all back together, wot a pain in the arse but there all gas tight now :) anyway I still have my second cat in and I had runaway boost, it kept rising to 18 psi then fuel cut occured but now I have my rr in aswel it has brought the boost down to a stready 13psi (0.9 bar) in every gear which is good, but its a little low now:( I want about 14.5 psi (1bar) I think I need to file some of the rr away to make a bigger hole but does anyone know by how much?

[Flip]

Trial and error - take the ring out, file a bit off, put it back in, see what peak boost is. Rinse and repeat as necessary.

Alternative is to get a nice boost controller in there to sort it out for you, that is the best way, it'll will give you a much more reliable and scientific approach!

[Ric]

My RR is 2.1 2.2 " Internal diameter and is giving 1.0bar with the 2nd cat in.

[Lewis]

agreed, I think a boost controller is the order of the day here, you will be hitting higher boost levels due to the cold weather, once summer comes along you may find your boost levels a fair bit lower. Go with a BC and you can up it when required.

[Flip]

Trouble with going to 2.1" diameter is that might put you over! Each engine boosts differently, there are people on here with no RR in there not getting above 1 bar!

Definately boost controller, you get a few on the for sale area for between £100-£150... Or spend £400 on the i-color coz its really cool! That's got more features/options than an S-class Merc!

[Soonto"HAS"soop]

So what's so wrong with 18Psi then? OK, it's probably a little high if you still have the 2nd cat in place, but it isn't anything overly bad though. I used to run my twins with no cats at 18 Psi all the time, they lasted fine.

[Chris and Alana]

So what's so wrong with 18Psi then? OK, it's probably a little high if you still have the 2nd cat in place, but it isn't anything overly bad though. I used to run my twins with no cats at 18 Psi all the time, they lasted fine.

because it wasnt steady it was creeping up to that boost and would go further if fuel cut didnt happen. the rr is keeping a nice steady boost level.

So can I just buy a EBC and up the boost? will the EGT's be ok with the second cat in and a rr and then turning the boost up to say 1.1 bar?