Luis de Prat

I'm asking about chips in general, and own a 951 myself. Thanks!

NZ951

Oh my bad, I thought you were asking about your friends 968 only...

Is your car coded 951? I would have thought 952... Or is it another given its a cab?

Luis de Prat

AFAIK, you're the one with a 952 (Right Hand Drive version).

I've heard some people call the turbo cab a 953, but the factory never had such an internal designation. The S2 cab was a 941, however.

So you wouldn't hesitate to chip a stock '91 951? I'm really concerned about blowing the HG. This thing roars pretty good when I get on the pedal, but one of those bad RS6s pulled away from me recently and it got me thinking!

Rich Sandor

Luis: The horror stories you hear about guys blowing headgaskets are cars running 20+psi at the track doing lap after lap at redline.

15psi w/ chips really is a mild (on the engine) upgrade that yields an unbelieveable gain in HP.

But chips alone won't do ****. you really need to up the boost a little bit. trust us..

do a search and see how many cases of blown HG's you can find and see what boost they were running and if it was at the street or track. (and whether or not it was caused by coolant/cooling problems or something else other than boost..)

Evan70

I've seen 952 used a few times on the net to designate the 944 Turbo S (or 89+ 951s).

One thing to remember when talking about chips/ECM reprograms whether it be a Porsche or any other car, the manufacturer has to set up the car to be able to run on 87 octane gas. Sure they specifiy 91 or higher on the 951s, but you know there are people out there that will run them on the cheapest gas they can find. Also, there are many owners out ther who don't do the recommended maintenance, which the factory also takes into account when designing the computer tune. When you start dealing with chips/ECM reprogramming, the tuners will take into account that they are dealing with an enthusiast who will actually run premium (91-93 octane) gas, and who keeps their car in a good state of tune.. This allows them to optimize the timing, and in the case of the 951s to raise the boost limit in relative safety. Of course, all of the chip/ECM tuners have a disclaimer somewhere that if you blow up your engine it's not their fault. Anyway, I've had chips/ECM reprogramming done on just about every performance car I've owned. In some cases it didn't gain much (maybe 10HP on a 300HP car), but in some cases (especially Turbos) it can make a huge difference. Right now I've got a set of Autothority Stage II chips sitting on my shelf, but I'm actually planning on selling them and going with Vitesse chips instead. Not because I think their is really anything wrong with the Autothority chips, but because I've heard great things about the Vitesse chips running a little better and providing a little more power.

NZ951

952 is def the RHD 944 Turbo. I thought your cab would have been.

If you are happy with the performance then let it be. If not, then make sure the mods you do will be inline with any future modifications you may have in mind. If it is tuned well, more boost is fine. I didnt want to run over 15 psi with the stock HG, so I put a WFHG in. Some say 15 psi is the limit of the stock HG, some say they run more and have no issues. On your car, a chip and some boost may be an easy way for another 30 odd HP and a bigger smile and not too much to worry about problems wise...

Peckster

Not all. I was getting spikes maybe to 17/18, but that was the LBE, ] not the chips. I think APE is safer than Guru, they run richer.

theedge

No there is no major concern. Make sure everything else is in good shape, new plugs, etc.

Chips take an hour to install and will make a HUGE difference. For better results, add in better boost control. That can vary from $60 for an LBE, to hundreds for an electronic boost controller. If you want to continue, then a new wastegate is another good thing to consider. Those three things will make it feel like a whole new car, and its hard to see them thus keeping the stock appearance that you want.

Two points of caution tho, research the chips, APE chips arent ""happy"" with a boost controller or wastegate, they are aimed at stock cars. GURU and other sell a kit. Second point of caution... Resist the temptation to continue upgrading if you want a stockish car

Porsche-O-Phile

On the upcoming dyno day I'll try one pull with the stock chips and one with the Weltmeisters. That should give you some data. My car is basically 100% stock other than the chips right now so it should give a nice benchmark for comparison.

NZ951

See this is the problem! You get some chips and a boost controller, then you cant hold boost to redline then you need a Tial... it goes on! lol you will get hooked if you even start!

facboy

i don't think that is the case. both are fine provided you run them within the parameters specced by the tuner. Gurus are designed to be run with a basic MBC set-up (as are vitesse, afaik), which is what most people go for.

APEs are designed for the modified banjo bolt and that only. the problems seem to arise when people run additional modifications (eg an MBC) with the APEs. but people usually want to fit an MBC, and you'll likely get more power from an MBC and guru/vitesse setup than from the APE setup at the same boost level - as i understand it, the APE boost curve falls off much more quickly than the MBC setup.

Porsche-O-Phile

Nah, all I'm going to do for now is run the Welt chips and the shimmed 'gate. I've got too much other work to do on the Callaway project and my friend's car soon. It'll also give my wallet a much-needed rest for a while. Eventually I'll go with a larger turbo, Tial, 18psi chips (probably Guru) and the Guru stage II MAP kit, but when I do that, I'm going to do it all at once and not the "piecemeal" approach. Better to do it right all at once and get what you want, rather than taking a hit on cost by making an extended series of little upgrades. The car is plenty fun right now. Yes, I'll turn it into a monster, but I'm in no hurry and can bide my time. . .

theedge

APEs are designed for a stock car with a stock boost control and thus a stock boost curve. Thats what they are mapped for. Adding better boost control results in holding more boost in the high RPMs, and since the chips arent programmed for more boost high up, they lean out. Lean = bad.

Nothing inherently wrong with the chips, just when people run them with other mods (im guilty).

nize

luis, i bought my '88 951 new directly from the dealer and for 16years i've driven it completely stock. all those years i've resisted the temptation to upgrade the chip because i knew they'd get better and better and i was also afraid the earlier chips may have some bugs. i have friends who chipped their 951's many years ago who have blown their engines long ago, among other things. so i completely understand your hesitation when it comes to chips. my philosophy also was: if porsche could have made it better, then they certainly would have.

i now feel that chips for the 951's are about as good as they'll ever get, and the ones that are still around are around for a reason, nobody is going to buy a chip from a company that has a bad rep. so i dyno'd my stock car in order to have a general baseline data.

a few weeks ago i finally replaced the stock exhaust with the 3" lindsey and installed the lindsey boost enhancer, then dyno'd the car again.

two days ago i installed the APE2 chip and dyno'd the car again.

the difference is truly phenomenal. you can see my three dyno readings in the graph on this thread;

https://rennlist.com/forums/944-turbo-and-turbo-s-forum/175881-stock-87-88-turbo-rwhp.html

i would enthusiastically recommend you upgrade the chip in your 951, even if you do absolutely nothing else. you will wonder why porsche didn't upgrade the chip themselves long ago, and then you will wonder why you didn't upgrade your chip long ago.

Luis de Prat

Thanks for all the responses.

Another question: how do the chips affect top speed in the 951? Am I wrong to assume that there is a gain in HP but a loss in top end speed?

Dyno HP figures are great and all, but speeding is more common in Europe than in the U.S. and I do a lot of high-speed driving on the Spanish highways.