Is the stock compression different in 99-00 stangs and 01-04 stangs. Ive heard a lot of talk about this but never a clear cut answer.

 

yes the romeo engines have slightly higher compression

 

The only "concrete" proof I have seen of this was a printout from a ford website that stated it was slightly different.

However, what I saw had the newer cars with higher compression, but the same dish piston, same rod/crank stroke, and a LARGER combustion chamber, which would mean the exact opposite.

My vote goes to someone at ford screwing and making a typo, and it never got fixed in the data. In any case, the compression is so close that neither car will show any real differences on the dyno.

 

I know the romeo engines are 9.4 compression as I have one and just finished building it. I was told by my tuner that the windsors have 9.0 compression. I'm not sure how true that is.

 

surely it cannot be that big of a difference... you would be seeing fairly signficant differences on the dyno, not to mention pretty different tunes etc.

 

I think my tuner told me that so I wouldn't fuss at him. I have 9.4 compression now and wanted to run 16 lbs of boost. He said that was too much for pump gas so I left it at 11 lbs. A couple of months later a friend of mine was getting his car tuned and my tuner slipped up and told me he just got done tuning another gt that had a stock motor, which is 9.4 compression, that made 16 lbs of boost. I asked him if it was on pump gas and he said yes. I said well mine has the same compression as his and that's when he told me the Windsors had 9.0 compression so it was ok to run that much boost on it. WTF?

 

see ben, you dont know everything....

 

No. I just act like i do! lol. But still no clear cut answer [:@]

 

Yes there is a difference. 99-00 had 18.10 cc dish pistons and 01-04 had 15.80 cc dish pistons. So the above statement from the guys tuner is somewhat true but the ratios are a little lower