tuning question

[dhen]

Hi everyone,

My engine is getting rebuilt and I'm not sure what, if anything, I should do about my tuning. My engine will be the same as before, but will have a 4-port euro head on it.

My engine was stock and I was running 10 psi boost before I spun a bearing because I lost all oil pressure. Someone had adjusted the tuning and when the engine would first start up, soot would come out of the exhaust pipe until the engine warmed up a little. I don't know if this was condensation in the pipe or running rich, but it would run fine afterward.

Does this sound like I will need a rechip? If so, does anyone know someone who could do this? I was also thinking about doing the exhaust cam trick, but that would be later if ever.

By the way, I saw this on eBay. Would there be any benefit for me? I plan on running about 10 psi of boost.

http://cgi.ebay.com/ebaymotors...A1318

Thanks,

Darian

[sjbsuperman1425]

from what i've heard, the eBay ships are fail..check out the eBay thread, there MIGHT be something in there about them..

i dont think a 4-port head would make much a difference tuning wise, but i'd probably set your timing to stock and then see if you are still having soot out of the exhaust..

[dhen]

from what i've heard, the eBay ships are fail..check out the eBay thread, there MIGHT be something in there about them..

Sorry, didn't seethat. There's lots of info there. It seems that the cheap eBay chips are copies of established maps, so you're taking a chance that the copy was done right.

Any other ideas are welcome...

Thanks,

Darian

[Buddyworm]

CA's like to run rich on startup. I think they just overkilled the startup enrichment, which would explain why pulling the fuel pump fuse after priming the lines can get your car started.

My engine will shoot soot onto the pavement for a few minutes before things start to warm up. Otherwise it just hovers around stoich and burbles happily away.

That said, I highly doubt you need a retune. The different flow characteristics from the 4 port head aren't going to change things enough to make the stock maps unuseable. You won't be able to notice a difference, plus, when you start upgrading things like your turbo, getting the car tuned will optimize everything for the different head anyway.

[dhen]

CA's like to run rich on startup. I think they just overkilled the startup enrichment, which would explain why pulling the fuel pump fuse after priming the lines can get your car started.

My engine will shoot soot onto the pavement for a few minutes before things start to warm up. Otherwise it just hovers around stoich and burbles happily away.

Thanks, that's exactly what my engine would do. I guess this is normal?

That said, I highly doubt you need a retune. The different flow characteristics from the 4 port head aren't going to change things enough to make the stock maps unuseable. You won't be able to notice a difference, plus, when you start upgrading things like your turbo, getting the car tuned will optimize everything for the different head anyway.

I suppose you're right. I was more worried about the soot. I don't want to kill a new engine.

[Buddyworm]

It'll be fine. Soot's not gonna kill the engine. You'll start fouling plugs like mad before even have to worry about cylinder-wash.

Little bit of a rich condition on startup is a lot better than way too lean anywhere.

[dhen]

Thanks. I guess I have to keep watching my spark plugs then.

Darian