LS1 cam to pass MOT plus mapping recommendation

[Buffy d]

Hi all, I've got an auto' LS1 Camaro and am looking to get a cam for it. I've done lots of research regarding overlap and understand that around 0º or less is the safest way to go regarding passing an MOT, but wanted to run my two frontrunners past some people in the know. I've narrowed it down to two from Texas Speed, the 224R (224/224 .600"/.600") on a 112LSA, or the 228R (228/228 .600"/.600") on a 114LSA, both of which will give me an overlap of 0º. I like the idea of the 228R but I'm worried it might be cutting it a bit close on the emissions front? Any advice much appreciated. Also, if anyone has any suggestions regarding someone in the south east who could map the car for the cam, as well as some other mods I have lined up, that would be brilliant. Thanks guys

P.s. I know it's not a Vauxhall/Holden but I figured this forum would be the best/busiest place to go for LS1 knowledge

[Phillphill]

I fitted a cam recently, and to be honest I am really not fussed about the emissions.
I know its potentially not the best way to go, but none of my second or track cars have ever sat through an emissions test!

[stevieturbo]

Buffy d said:

Hi all, I've got an auto' LS1 Camaro and am looking to get a cam for it. I've done lots of research regarding overlap and understand that around 0º or less is the safest way to go regarding passing an MOT, but wanted to run my two frontrunners past some people in the know. I've narrowed it down to two from Texas Speed, the 224R (224/224 .600"/.600") on a 112LSA, or the 228R (228/228 .600"/.600") on a 114LSA, both of which will give me an overlap of 0º. I like the idea of the 228R but I'm worried it might be cutting it a bit close on the emissions front? Any advice much appreciated. Also, if anyone has any suggestions regarding someone in the south east who could map the car for the cam, as well as some other mods I have lined up, that would be brilliant. Thanks guys

P.s. I know it's not a Vauxhall/Holden but I figured this forum would be the best/busiest place to go for LS1 knowledge

As a US import...exactly what emissions levels do you need to meet for the test ?

[ringram]

zero overlap in theory means both cams should be the same.
Though one will be more efficient at lower rpm than the other one due to valve events.
The lower duration in theory will have later exhaust and earlier intake etc.

Cats are going to be very important.

[Buffy d]

ringram said:

zero overlap in theory means both cams should be the same.
Though one will be more efficient at lower rpm than the other one due to valve events.
The lower duration in theory will have later exhaust and earlier intake etc.

Cats are going to be very important.

Yeah, I'm thinking the 228R as I'm already running a 3.73 rear end and will be get getting a 3600 stall torque converter, so getting into the power band quickly shouldn't be a problem. In terms of cats I was thinking something along the lines of high-flow 200 cell ones, would they be ok?

[ringram]

You want zero backpressure and maximum exhaust velocity, that is the correct answer.
What that means in terms of cat is for you to find out

112cfm per sq inch of exhaust and you need around 2.2cfm per bhp.

http://www.superchevy.com/how-to/exhaust/0505phr-e...

[MyM8V8]

I used a 224-232 114 lsa and without cats, was a pass on emissions for an import. This was on a 6.0L motor. You are auto therefore will need a good remap for off idle. I originally had problems with stalling out (not very nice or safe) and quite a few goes to get the map right for that.

Not sure you would need such a big stall convertor using 3,73's?? Presumeably you have 4L60E?

[Monaro5.7]

I have a 223/231 cam with 112 I think been that long since install. I also run 200 cell cats and I pass emissions every year.