Thinking about long tubes, fast intake and tune. About how much gain can I expect with all three ( `98, auto. ) Or is there a better intake? Thanks

 

If that's all you plan on doing, you may be disappointed with the FAST intake (comparing $$ per horsepower).

 

The FAST would be a good complimenting part later, but if those are your only mods there are better places to spend the money you would spend on the FAST. Do you have a cold air intake yet (Honker, Vararam, etc.)?

 

came with a Vortex. Thought a fast 90/90 would go with long tubes.....no?

 

FAST 90/90 is better suited for when the motor is breathing better. For the cost of the FAST, you can pretty much do a cam and the $$/hp from a cam is much cheaper. Other option if you don't want to go into the motor would be gears. You can pick up a set of used 3.42's which would go good with your auto for about the same price as the FAST. Not any more hp, but it will definitely sit you back in the seat more

 

With your setup a LS6 intake & porting your stock TB would be the best. The FAST is the best performer that we have found with a heads/cam car, but your stock heads/cam are to restrictive to make the FAST work. Your engine needs every component to work together in the most efficient way possible, and if you are staying w/your stock heads the long tubes, LS6, CAI & a good tune will give you about as much gain as possible as far as HP. Now add a lower geared rear & if an A4 a good 3400-3600 stall convertor & you will be amazed.

 

How much gain we talking here with just long tubes, LS6 and Ported Throttle Body, CAI and a good tune ? What is the stock rwhp for a 345 C5 A4 ? I heard it's a 22% loss ... so that would be in the 260's on the dyno ? Another was 279 for a stock C5 A4 345 HP

 

Bone stock we see 270-280 range w/A4 C5's.....expect around 20-30 (under promise, over deliver) rwhp gain w/those mods.....but the results at the track can be as much as a full second reduction in ET with the proper tune & the CAI working at speed. Now a good TC will drop you .5 sec ET as well.

 

to prevent large amounts of disappointment please skip the fast intake. While it's a high volume intake and superior to OEM intakes avail for the LS1/2/6. Your intake isn't really a restricting point...

Get a used LS6 intake off a member who is getting a fast intake... The LS6 intake will still produce a gain and at a fraction of the cost. Also the Fast intakes have a nasty rep. for fitment issues. All the work and money invested for not much gain and possible "leak" issues to deal with would make you wanna beat your head into a wall...

New fast intakes run about $900

Just my .02.. i'd toss your current CAI into the trash and get a VARARAM intake (380ish new from forum vendor) and a cam... deciding on a cam is a whole other thread. Get yourself well educated on picking a cam right for you before you make the purchase. YOu will also want to replace rods and springs while your in there..

WIth a 228 cam, LS6 intake, Vararam, LT's on my 98m6 i make 370 at the wheels. I was 380 last year with corsas but now i have z06 ti's. my best time is a 12.4 at 118mph. my 60's are forever stuck at 2.0 on street tires. My clutch is the limiting factory. Old worn out clutch made a 1.85 run but stuck to the floor afterwards. I'd say the car is good for very very low 12's possibly even a high 11 sec pass at my fairly high altitude.