foxtrot

Ok I just bought my 1998 GT only to learn maybe I should have got a 99 or newer with the better heads. So on to what I am asking for:

Ok maybe too much has been written about this already (maybe that’s why I am confused). The parts suppliers/makers claims appear to be bogus or under certain non real world conditions that are not up front. I have read many reviews about getting more performance from the 4.6 that basically say don’t bother unless you change heads use non hypereutectic pistons and add a blower.

So I am looking to you guys to find the “REAL” scoop to find the best bang for the buck (<$500) to add some ponies under the hood and maybe even gain some MPG I don’t care if its louder as the stock exhaust is relatively quiet for me.

devinsteen

YOur 98 GT is just fine You are correct about hp claims...usually they refer to Fly wheel hp. We care about Rear wheel HP. That is how much you actually put to the ground. The PI head/ intake swap is the best mod for your 98gt. But there are many other bolt-ons that will give you better perfromance and hp.
1. I would say to start with gears. The 2.73's on our 98's blow ***!! Go with 3.73's (daily diver) or possibly 4.10's. YOu could get gears and have them installed for 500 or less.
2. Exhaust is a must The stock set-up is restricive. Look into getting some headers($300-400), a mid-pipe ($170-200) and a cat-back ($300-400).

This will get you started in the right direction. Hope it helps

mdvaldosta

definately gears & exhaust

foxtrot

Gears I know I will feel and exaust I will hear so good ideas.

What will gearing down do to my MPG? I have a 40 mi commute one way so I would like to push perf in the same direction as MPG. I think the exaust might give me all that but headders alone and an exuast system will probably not do much in terms of HP/TQ.

What about reduction pulley's ? Can anyone tell they have em?

I will not even ask about MAS changes or Cold air as all of it sounds like good marketing and a waste of my hard earned cash.

Bring on some more stuff guys what about a chip alone? Wil that do anything. If so which one?

foxtrot

feel the grear change.....I meant

Cedarkill

Hey, the gears will only hurt you're mpg if you drive a lot of highway or constantly drive with a heavy foot, haha. Now, I don't have gears in my car, but for daily driving on a 30mph or 40mph your mpg shouldn't get hurt. I mean, if you normally cruise in 3rd on a 30mph road, you'll have to cruise in 4th with the gears to keep your rpm's low and your mpg shouldn't change much at all, right? This is a stretch, but in theory i guess, haha, thegears should help your mpg if you drive a lot of stop and go because a 3.73 gear ratio is a lot easier for the engine to get turning rather than a 2.73 ratio. But if your car seesa a lot of highway driving, then yea, the gears will cost you some extra bucks in gas. As far as underdrives, I'll let you know this week, mine are coming, haha. They won't make a dramatic difference of course, but I was sold on them because they're such an inexpensive and easy to install mod. I'm getting steeda underdrives and a timing adjuster. I read the underdrives in conjunction with the timer advanced to around 13 or 14 degrees is good for 10rwhp, and 25 ft/lbs of torque, on a dyno. that was on a PI stang tho, but you get the idea, I'll let you know how they work out.

deesgt

Can you explain the timing advance thing. You are'nt referring to ignition timing are you? Cuz i thought 94-98 Gt's ignition timing was not adjustable.

Cedarkill

Yep, you're right, the timing is fixed. From what I gather and have read, the timing is set at 10 degrees BTDC stock, and uses a magnetic sensor which is placed in the front of the crank case to monitor this and what not. Now, Steeda makes a timing adjuster, actually they have two models, but what they do is take that sensor out of the crank case and mount it aligned with your crank pully/dampener via a specially made bracket included in the kit. Then a plate is attached to the crank pully which the sensor reads from and is adjustable rotationally to advance or retard the timing. Check out the Steeda site, they do a much better job explaining than I do, haha, but it seems like an easy install and simple concept. In general, like with distributor engines, advancing timing is an easy way to tweek some more power, but obviously you can only advance it so much. I mean, advancing a 4.6 to say 14 degrees will require 93 octane, from what i'm told. I have my adjuster and underdrives coming in the mail, I'll leave a post at the end of the week when I have them on and how they work out.

Acer2428

let me know if you have to pull the crank bolt to install the TA adjuster.

deesgt

Ditto on the crank bolt info. I know it's torqued pretty darn good