Author Topic: Engine differences (Read 3763 times)

pbshow · « **on:** June 21, 2009, 03:21:57 PM »

Hi all,

I have a 1998 GT convertible with the 225hp motor. What changes in the motor did Ford do to the 1999 4.6 to get the extra 75 ponies? Cams, exhaust, computer....?
How can I get the extra 75 for my '98?

Thanks,

Show

Soaring · « **Reply #1 on:** June 21, 2009, 03:45:04 PM »

1996 to 1998 is the same for all SOHC Mustangs, you can install a 1999 to 2004 4.6 SOHC "PI" engine, which has better intake manifold, cylinder heads and cams....but you will have to change the front timing chain cover to your year and if you get a 99/00 you'll have to get a different flywheel to as your car, being a Romeo engine has a 6 bolt flywheel and 1999/2000 are Windsor engines and have a 8 bolt flywheel.... So, to answer your question, you will need to find a 99-04 4.6 engine if you want the extra 75 ponies.

pbshow · « **Reply #2 on:** June 23, 2009, 01:38:24 PM »

Will the 99-04 computer interface with the '98 chassis?

jethat · « **Reply #3 on:** June 23, 2009, 05:38:33 PM »

you can use the stock computer but it needs to be tune for the newer engine...

Blown2v · « **Reply #4 on:** August 20, 2009, 08:52:21 PM »

might as well just do a complete 4v swap lol

tazmanhawaii · « **Reply #5 on:** October 02, 2009, 01:27:37 AM »

You can also do the PI swap. Get the heads, cams and intake from a 2001-2004 motor and bolt them onto your 98 block. These were the parts the gave most of the power change to those motors. Being that you have the Romeo block, it is easier to find the 01-04 parts as they are also Romeo motors. Some good write ups can be found at the SN95 forums for these swaps. Either way, you keep your ECU and timing chain cover.