I think its about time I looked towards waking my car up a bit after being stock for the last couple of years. I have a 1995 LT1 M6.

My problem is that I live in the UK and have no idea what kind of emission output comes from having each grade of the popular cams. I'll give details of the annual UK MOT test emission requirements here along with my results with a stock car:

Emissions at idle:
CO output no more than 0.30% (I got 0.27%)

Emissions at fast idle (2500-3000rpm):
CO output no more than 0.20% (I got 0.00% last time)
HC level output no more than 200 ppm (I got 5 ppm)
Lambda must be between 0.97 and 1.03 (I got 1.01)

I hope some of you can relate to this standard of testing, and recommend what kind of limits I can go to with duration and LCA.

My personal requirements are a bit of lope (enough to sound like a V8 should and not the fast hum of the stock cam). I use my car daily and spend most of my time between 1000-2000rpm so would need at least the stock torque at that engine speed, I never use the redline so I don't need a high rpm cam, the only racing I do is on the street from a roll. I would also like a decent amount of power over what I have now. The best sound clip I have heard so far is a 230/236 through an Edelbrock muffler, the cc306 clips all sound too vicious to me, and I need subtlety because I don't intend on telling my insurance company about this. If they want to inspect the car at any point I can wind up the idle on a mild cam to hide the lope.

I am currently running bascally stock and stock heads (unported) and stock gears. My mods to date are a 160 degree thermostat and CAI, and for the time being, no muffler just open pipe!

If I went ahead with a cam, I will compliment it with most probably the Mac headers and cat, roller rockers, springs etc, I may or may not put the stock muffler back on and run the ORP or a cut out when its not near testing time, failing that I might just keep the open pipe.

After searching through all the previous cam topics I have narrowed it down to a 218/224-112, 224/230-112, 305 or the Hotcam. I not sure about the LCA Vs emissions what with the overlap.

I hope you can forgive the long post but I don't want to waste my money on a cam that will fail the emissions test and require a top end unbuild and rebuild just to pass.

I must also ask is a tune absolutely necessary, its a lot of hassle for me being in the UK and I think for that reason Madz28 don't want to know me!

 

I know those are all emission friendly cams so I doubt you will have a problem.

Alittle off topic here but what do you guys pay for gas there these days?
I was just wondering cause I know it is crazzy high and that car must kill you wallet.

 

It averages around here at 93 pence/litre thats about $1.60 per litre. So around $8 per gallon.

Yes it does kill my wallet, I get about 22mpg and $40 worth lasts me about 100 miles.

And also yes I guess the cam will make matters worse!