I have a 88 GTU and i have a mid pipe instead of the cat , and a K&N intake.
What sould i do next?

 

loaded question, what to you want the car to be? Drift? Drag? autoX? daily driver? or just wicked fast?

I suspect you would be better off doing some reading and searching. You will find many options.

 

Im taking it that its your dailt driver/weekend "racer." Id suggest next mod would be something like suspension. Racing beat has a nice package: springs, bars, and struts.

 

Yeah id like to make it my DD/ Weekend racer. Other than suspension what else to get some more power out of a N/A with out boosting or NOS?

 

dude, i had that exact same setup once! I found good mufflers gave a noticeable power boost... and then i bridgeported it :-D
One thing to consider is your wheels and tires. A friend of mine has an rx with 18's and 275/25 18's on the back so he can get traction. I'm pretty sure he can't do a burnout LoL (and he has the hookups for cheap tires) but its almost as nice to NOT second gear scratch as it is cool TO second gear scratch :-D
I'd go with 245/40 17's if you can afford um, otherwise 225/40 17's.

 

I wouldnt worry about upgrading your tires/rims untill you start having problems with traction.

 

Oh i forgot to mention i have the 3rd gen wheels and potenzas on it. looks and handels sweetly.

 

Im still leaning towards suspension. It will make it feel tons faster. Quicker off the line, etc.

 

Alright Ill have to gather some money up then. unless anyone has any ideas for some cheap HP?