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Thinking about a future project. I have (wife's) a 99 A4 coupe with CAI, LS6 intake, 1 3/4 headers, high flow catted X pipe, TIs and ECS mail order tune. If I have the stock heads worked, will I need the LS6 injectors or will stock injectors be okay still?
Thinking about a future project. I have (wife's) a 99 A4 coupe with CAI, LS6 intake, 1 3/4 headers, high flow catted X pipe, TIs and ECS mail order tune. If I have the stock heads worked, will I need the LS6 injectors or will stock injectors be okay still?
You shouldn't need an upgrade unless you do a cam. But you can have your duty cycle checked out if you're worried about it. If it's up high at 90% or or close, change them out. But 80 to 85% or lower isn't a cause for worry.
If I have the heads ported and polished and put on an 01 or newer MAF ( I have read they are bigger than the 99 MAF) I will need a tune also, won't I? But if I don't need the Z06 injectors I have, I guess there is no point in swapping them.
Did a little research into the MAF. The 01 and up are 85mm and I believe the 97 - 2000 are 78mm. I don't understand how having a larger TB than MAF could help since the MAF is going to be the limiting factor. That said, it seems as if in my car, that is not heavily moded, changing to a larger MAF is simply a waste of effort. Got stock heads at a really good price so, when I have the funds I will get them ported and polished and swap them out with the 70K mile heads. Not expecting anything noticable in seat of the pants responce, just feeding my illness.
P&P makes a big difference when cammed. You can also mill them down to bump up compression. I think stock is around 62cc. TFS makes 58cc heads for the LS engines. You'd be safe to take them to around 60cc and still be able to run power adders if desired in the future. Whatever you do though, when you replace the heads, definitely put in LS7 lifters and LS2 lifter trays. That way if you do a cam in the future, the heads won't have to come back off to replace those important parts.
Did a little research into the MAF. The 01 and up are 85mm and I believe the 97 - 2000 are 78mm. I don't understand how having a larger TB than MAF could help since the MAF is going to be the limiting factor. That said, it seems as if in my car, that is not heavily moded, changing to a larger MAF is simply a waste of effort. Got stock heads at a really good price so, when I have the funds I will get them ported and polished and swap them out with the 70K mile heads. Not expecting anything noticable in seat of the pants responce, just feeding my illness.
What stock heads did you pick up? I would not put money into having them ported unless they are Ls6 243 heads. A good porting job will often cost about as much as a set of aftermarket heads. I have over $2000 in my porting job on my Ls6 243 heads.