Performance Chip Sets - Worthwhile?
>I'm thinking about a performance chip for my 88 S4 A/T. What are the
>advantages / disadvantages?
Biggest advantage is it makes it just a little easier to humble those C-5 Corvettes in my GT, the only disadvantage I can find is that I drive my GT even harder than before (if you call that a disadvantage) ;-)
Seriously, before I go into this I must tell you in all fairness that I have recently started to sell Autothority Chips through my company "928 Specialists", so you can take my feedback however you like. I will say however that I used to be very "anti-chip" like a lot of other people and still am if all I see is 1 or 2 chip sets offered by any Chip Set maker for a 928. Also of note the reason I am now selling Autothority Chip Sets is because of my personal experience described below.
I recently installed a set of Autothority Chips in one of my 89 GTs in an effort to test them before selling them to my fellow 928 owners. After plugging in the chips I fired the GT up and immediately the engine felt different, the throttle response felt much crisper and the engine felt stronger just sitting in the garage "blipping" the throttle. Out of the garage and on the road my next pleasant surprise was an noticeable increase in mid-range power and drive-ability. I own both an 89S4 and 89GT (actually 2 of each) and one thing I have always noticed about the GT was that it lacked a little of the mid-range torque that I had come to know and love in my S4 5-speed due to the fact that the GT's torque peak is at 4100rpm vs the S4's 3200rpm. The first thing I noticed on my first test drive was that this in now changed, the GT now felt as strong or stronger than the S4 in the mid-range!! For example, when at a steady cruise of 80mph (3100rpm) in my S4 I could always just press on the gas and have plenty of torque for passing quickly in 5th gear because at this rpm I was actually in the main torque peak on the S4, however doing the same in my GT was always noticeably less (until it reached around 3900 and up). The main word here is WAS, now the GT feels stronger at that same test than the S4 ever did. This alone makes the chips worth it to me. Since the GT already screams on the top end, the results there were not as noticeable as in the mid-range, but still very obvious to me.
Also of note is the fact that the GT is already pretty "tweaked" at the factory on the top end from Porsche. This is also evident in Autothority's HP claims, the GT actually shows the least amount of HP gain when compared to the S4, 30hp gain for the S4 and 24hp gain for the GT. This quite frankly furthers my confidence in Autothority's claims due to the fact that it is inline with the actual differences in the HP of the GT and the S4 from the factory (S4 316hp, GT 326 hp). A lot of other chip makers out there claim the same gain for both types and even say to use the same chip set in an S4 or a GT, hence my previous lack of faith in Chip Sets since I am so aware of the many differences in the 2 engine types.
To "double-check" my enthusiasm of these results I drove around in my GT with 2 sets of engine computers (one set with the original stock chips the other set with the Autothority Chips) so I could "Hot Swap" the brains in just a couple of minutes to get a true "A - B" comparison. The differences were the same as I originally perceived and just as obvious every time I switched back and forth between the brains.
>How is fuel consumption affected?
Don't know, don't care, however since the engine seems to be operating more efficiently I would suspect that if I tried to take it easy and keep a steady cruise it would be the same or maybe a little better. This, I have always found very hard to do in a strong running 928 especially with the sound of an RMB in the background. However, maybe I can find a doctor to prescribe me with some Valium or Prozac which might better aid me to keep a steady "non-warp" speed in the GT.
>Do they actually give the increase in horsepower advertised?
I plan on doing some independent dyno testing to see, the only reason I am doing this is just to give everyone else some feedback. From the drivers seat it is very obvious that the chips work and quite frankly I personally could care less about what the dyno says. Remember a dyno can show a lot of things on paper and is great for documenting changes and upgrades for product development, but in the final analysis I go by what I feel on the street which is where I drive, not on a dyno.
>At what point does the extra horsepower come in?
In my experience throughout the powerband with the peak obviously in the upper range. However on a GT expect more noticeable differences in the mid-range as described above.
>Which chip is most preferred?
IMHO, Autothority seems to be the most knowledgeable when it comes to Porsches and have developed the widest range of chip set offerings for the 928. With my ever closer relationship with Autothority I see even more offerings for the 928 in the future. I could probably sell any brand of chip I chose, but I chose Autothority for many reasons, results, widest range of Chip Sets for 928s, great Customer Service and what I feel will be a company that will work with us to develop even better Chips for our stock and modified 928s in the future.
>Is it really worth getting one?
I am ordering a second set for my 89 S4 , and will be getting a third set for my other 89GT when it is finished going through it's extensive metamorphosis. In other words I say YES. Also keep in mind that Autothority Chips come with a 30-day money back guarantee, "Try them and if you don't like them you can return them for a full refund"
One last note, do not expect the result to be like bolting on a Turbo or Supercharger. However if you are "in tune" with how your 928 feels and performs you will notice the difference and nothing else out there can give you the results you will see for the amount of money and ease of installation.
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