jda407

Hey folks,
New 968 Cab owner. Wondering about added horsepower options on these cars without turbo charging. Any easy, quick tricks to get some more hp's?? Are the chips that I'm seeing advertised really accurate in their hp increase? Are they worth the $'s? Do they affect the reliability and longevity of the 968 motor?

Like I already said...I'm new to the 968 and looking for options.

Thanks for any help.

RajDatta

Jim, depending on your budget, there is some power to be made. Chips seem to add approx 10-12hp and so does the airbox mod. After that it gets tricky and expensive. There are a few options with exhaust and headers. Then you can do mods like machined heads and cams. It all depends on your goal and budget.
What is it that you are trying to achieve and how do you plan to use your car?
Raj

jda407

Hey Raj,
Small forum to see your name again. Thanks for the response. It's my wife's car and she's coming out of a Z3 2.8 and before that a '99 996. Loves the 968 but would probably like a little more power - torque in the power band. Not looking to do major mods right now as it is her everyday driver and she's looking to keep it for a while. So it would be nice to give her a little bit of "umf" to keep her interest. Where can I find info. on the airbox mod? Did it on my 993 and enjoy the minor added hp and the great sound.
Thanks

jda407

Hey Raj,

Still trying to figure out some larger wheel combinations as our car came with 16's. I like the ones on your Cab but I'm getting mixed messages about putting 18's on a 968 Cab. Some say spacers needed, others say no. Some say "good luck" because you're going to have a rubbing problems, others say no. My wife really likes those Carrera III wheels you put on. She also loves the '02 lightweight 5 spokes (She had them on her '99 996). But I just need to figure out what all the specifics are before spending the money on new wheels.

Any additiona input??

whakiewes

Jim,

Our cars are up and down on power. I just rode in another 968 coupe with half of my miles, and it was a dog. I had no explanation. It didn't have chip/intake/exhaust of my car, but it was a complete dog. I think the key to these cars is to to get them back in shape (rebuild/clean carbon in head, freshen gaskets, etc) and see where you stand. I never dyno'ed my car when I got it, but the chip/airbox made a significant but feel. When I did my exhaust I lost a little butt feel, but my G-Meter says I am a bit faster. <$500 budget then basic maintaining, airbox mod/KN, chip should do you good. You will notice a difference in feel, sound, and gas mileage. You can find more information about the airbox mod at http://www.968forums.com/index.php?showtopic=2085 . I tried to find it on Club Stuttgart, but had no luck (just wanted a fair battle ). As for the chips, its personal preference. My Racer X chip was good, but I tweaked it a little with my motronic programmer to get it better. The RS Barn chips are probably the superior products at this time, but it may change by the end of next week as these cars go. Your options on chipping are Racer-X(Speed6), RS Barn, Promax, Autothority, and that is pretty much it. Prices are all about the same, sub $200 range.

If your budget is a little higher, headers and an exhaust are really worth your time. They not only make a rather boring engine stock much livelier (sp?) sounding, they do show gains. Our stock exhausts are incredibly restrictive, but they were built well. Wide open exhausts such as my 3" will see a definant loss in torque, the upper end pick up was nice. My car really shines from 4100 (variocam kick point) on. Below that its lothargic, but I like it that way for right now. RS Barn ( www.rsbarn.com ) offers header/exhaust kits, as well as chips. Pete would probably work you out a good complete stage 2 or whatever chip, intake, exhaust, header kit for a decent price.

I am unsure what your wife wants, but I definantly am faster than Z3 2.8's, and have pulled on a 3.6 996 on several occasions. Our cars are decievingly fast. 2900lbs and 200-210rwhp puts it at or above US E36 M3's, way faster than S2000's, and about even with the standard 911 range. Boxster, even early S's don't stand too much.

Wes

Edit - As to wheels, the concern isn't spacing or diameters. All mechanical problems are same as the coupe. What people say is that the structural integrity that is removed from the cab makes 18" wheels really harsh. To each their own. I have 18" Champion RG5's and I love them (although I would sell them for the right money ). My ride changed a bit from the 16's, but on a daily basis my car becomes less streetable, so I gave up on caring. The key is finding lightweight quality wheels. What will kill your power feeling is big heavy 18" wheels. I shopped for ever before I went to 18's, and thought at first I wasn't going to like them. Now I love them, and I don't think 17's would do it for me.

SpeedBump

Well those two seem to have covered it for you. There are a lot of people running 18s with the 968 some with spacers some without, I believe it is the offset of the wheel that determines the need for the spacers. I also recall some talk about changes in suspension geometry with the 18s but I could be suffering from sometimers on that one.

Definitely get everything into good shape and then chip it and drill the air box.

Oh and link to the airbox mod

http://www.968engineering.com/pdfs/airboxmods.pdf

RajDatta

I think as White said, best thing to do is to make sure your car is in good tune 1st. You could be leaving a lot of power on the table if the car is not in tip top mechanical shape. Bigger wheels might make the car "look" fast but they in reality will slow it down from the additional weight, especially unsprung weight which wil effect the braking and handling as well. This is only important if you like to push the car a bit and are trying to get every bit of advantage as possible. In my case, looks are just as important. The 16's tend to look dated. Also, having 18's on a coupe and 18's on a cabriolet is totally different worlds. The cabriolet will be a much harsher ride and you will really feel the chassis flex when you hit the bumps.
The wheels fit without any rubbing and this is when my cabriolet is lowered. The 1st 20 hp will be a few hundred bucks, the next 20hp would be a few thousand bucks. Its dimishing returns after chip and airbox. Also, most of these mods might give you more hp but as far as torque, I am not aware of many mods that actually increase torque or lower it in the rev range. Our cars make max torque at a heady 4500rpm, an area which a lot of our cars barely see in daily driving.
Regards.
Raj

SpeedBump

The RSBarn actually does increase Torque as well as HP which apparently was a bit of surprise for those involved in the development. My cars pull much stronger down low now (butt dyno ).

RajDatta

White, I won't say its not possible but dyno charts would be nice to prove that is actually what is happening.
Just to give you an example. The Yamaha V-Max was famous for its V-boost. Something of a kick that was felt in the mid range and everyone thought it was unbelievable. When they dynoed the V-Max, they saw a big dip in torque and then the torque curve recovered. So essentially what people were feeling was not really an increase in torque, but more that the engine was no longer losing torque.
Its just an example and my point is that a lot of times what we "feel" might be quite different from what is actually happening.
Regards.
Raj

SpeedBump

I saw so many dynos I don't remember which mods went with which but I'm pretty sure with the airbox, chip and exhaust both went up.

It's really not that important for me either way as with most of the chips drivability is improved which is what most of the street driven cars need.

Damian in NJ

I'm very happy with my Promax chip.

RajDatta

I might start out with the Promax chip again this time along with Dave's airbox mod. Should be the cheapest hp upgrade out there.
Eventually I plan to upgrade the head and other bit and pieces to get 280hp. Atleast that is the current target, hopefully I will surpass it within the next year.
Raj

Jason Judd

Eventually I plan to upgrade the head and other bit and pieces to get 280hp.
____________________

Raj,

That's 280 rwhp out of the N/A engine?...great head work!

Why the heck did I turbo-charge mine, if you can get those numbers...****.

Jason

RajDatta

Jason, its not that simple. It will be a bunch of things. The largest gains will be from headwork. I expect Jon Milledge head mods to get me to 255hp without any other mods. From that, getting an extra 25hp shouldn't be that hard. Between dyno tuning, mods to intake system and exhaust and cams, I should be able to squeeze an extra 25hp.
This is all theory though but I hope to back it up. I will start by making sure I have a baseline before we get started. I will do some dyno runs soon so we know where we are starting.
BTW, 280hp and possibly 230-240 lbs/ft of torque is not the same as 380 lbs/ft of torque to the rear wheels .
Regards.
Raj

Jason Judd

Ah yes...that wonderful drug called....TORQUE!!

Forgot about that.

Still, that's going to be very nice!

Jason