Moderate Performance Upgrades.

Hello All. I hope to pick your brains again.
1988 S4 Auto US spec 74k
Since my overheat issue has been solved by you all. I can start to put some energy and money toward making a few performance upgrades.
The only upgrade I have made has been a RMB which does work very well and the car sounds very nice. What are your feeling on things like ECU chips? There seem to be some dramatic claims out there. Installing X pipes. And changing out the air intake setup. I have seen a few products specifically a thing called a Blackbird twin air intake system. Actually any idea's that the community may have will be strongly considered and most likely undertaken right away. My goal is to make this lovely car the best it can be. I am very open minded.
Thank you guys in advance!

Robert

Not sure any of the intake systems have proven to increase HP, but they may have and I just have not seen the dyno runs.

The X-pipe CERTAINLY produces HP and Tq gains! You might want to drop the RMB though as some say the car will be REALLY LOUD with that set up and as an '88 in TN I suspect you can dump the cats! Though the car will smell different and not in a good way w/o them. Some have put the factory rear muffler section back on and report that is just the right amount of sound for them w/ an X and no cats. The RMB change out on an '88 makes those cars sound just about PERFECT IMHO!

I'll let you know how my '95 sounds with X, high flow cats, and the Constantine (BSRC) RMB on it soon! I hope it will be back tomorrow. Of course the 89 and up cars all have the BIG resonators so they don't sound very loud at all with just the RMB change for instance (I MUCH, MUCH prefer my '88 to my '92 w/ RMB).

You can add a rising rate fuel pressure regulator as well as 35# Ford fuel injectors (at least I think I go the injector info correct...someone who has done it and knows more will jump in)...

Lets see, leave the stock air filter in place, it is better than a K&N...

You could put more aggressive cams in the car but they are pretty expensive and then you are really talking about some serious work as well...though you don't have to pull the engine or the heads, but it is still a big job.

I can't think of anything else...Oh, the biggest performance gain as far as acceleration is concerned would be to change to a later transmission with a shorter final drive ratio than the 2.20:1 in the '87-'89 S4's. I have a '90 trans in my '88 car now and holy crap is that car quick!

Unfortunately, James, converters are a requirement in Davidson Co. After all, it is Al Gore country around here.

Austin, didn't even think of that, but Al Gore needs you guys to NOT pollute so he can fly his VERY DIRTY jet all around the world puking out all sorts of nastiness high into the atmosphere! Not to mention light his 22,000 sq. ft. mansion!

Robert, the first thing you do to improve performance is to open up the exhaust so that the engine can exhale.
When you do this then it can take a bigger breath and the power happens.

The first thing I did was remove my cats and replaced it with a straight pipe.
By doing this I removed exhaust restriction and gained some power.

If your area requires you to keep the cats for emissions then you can still get a X-pipe and performance cats except it will cost more to get those horses. 20 - 25 hp
here is a link from the vender Roger (928rus)
forums.rennlist.com/rennforums/928-forum...ght=performance+cats

The next upgrade would be performance tuning or chips. I am not sure who has the best bang for the buck.

Brad

I would completely stay away from the chips for your car. They'll be Autothority or the respective knockoffs. They add fuel, and really don't do anything else. I really don't think you need an adjustable fuel pressure regulator, the S4 unit works fine in even boosted applications. More fuel does not make more power. Your stock injectors should be fine also, unless they are all clogged, or you're planning on maxing out the stockers (supercharger).

If I had an Auto S4 I would do the EIS (I think that's what the "blackbird" is) that you're referring too. Roger sells something like that, and an x-pipe. Then take your car and have it sharktuned by someone who knows what they're doing. I would hazard a guess it would be pretty noticeable.

Other than Cam work like James said, you could throw on a supercharger. Both will require sharktuning as well.

Just my $.02, I'm not an expert by any means. But, so long as your car is RUNNING like it came from the factory, the exhaust/intake/tuning should bump a little in the fun factor. The supercharger would make it an ENTIRELY different car.