951Porschiste

I've had my 951 since March 2003. The car came with unknown chips; that is the PO knew the car was chipped, but he had bought it that way from someone else. He still had the stock chips in a little plastic box. Last year I opened the DME to find out which type of chip was in there. Unfortunately, the only indication on the chip was a sticker with the inscription "95187 DME" hand written on it.

Today, I decided to try the stock chips just to see how the car would respond. The whole procedure took less than 30 minutes. The difference is absolutely amazing.

First, I had always found the idle to be quite erratic. I'd start the car and the engine would almost stumble down to 400 or 500 RPM and then rise to between 1 and 1.2K as it got warm. Now, with the stock chips it fires up instantly and the idle very rapidly settles at around 950 RPM.
Secondly, the engine runs much more smoothly and the acceleration is very progressive and linear.
Third, before, whenever I'd let off the gas to decelerate, the engine would stumble for a fraction of a second and then pick up again. This generated a very uneven deceleration with "buckling" of the car. Now, with the stock chips, this "buckling" effect is totally gone.
Fourth, before, there always was a fairly strong smell of gas from the exhaust (running too rich ?). Now, this smell is not as strong.
Finally, the car feels just as fast as before.

One has to wonder then what real benefit these chips had over the stock chips. I'd be interested in finding out what more "modern" chips could do to improve the stock setup.

lart951

I had the same problems when I had the "GURU" chips. I replaced them with my old authority and my problems are gone.

JDeitz951

My car runs smooth as silk with the Guru 18 psi chips. In reply to the first post, a badly programmed set of chips is certainly worse than stock. Even well-programmed chips have to be exactly matched to the rest of the components (boost level, fuel delivery, etc.) or the car will run badly.

JDeitz951

Another thing, Andre, now that you have gone back to stock chips, you should be sure you are still running stock boost. If the car also has a boost enhancer set to a higher boost level, you should dial it back to 11 psi or you'll run lean and do bad things to your nice running engine.

hally

aftermarket chips adjust fuel and timing maps to match a modified airflow, eg if you modify your wategate for better spoolup or add a boost controller. They typically run more timing advance also.

lart951

Best chips out there are Vitesse Racing he is a rennlist sponsor and also a man of his word. If you ever decide to upgrade your car give John a call. If you don't believe me do a search for Vitesse.
here is his website
http://www.vitesseracing.com

superloaf

Andre,

I had some similarities with my car which was running Weltmeister chips but no waste gate shim or banjo bolt to raise boost. It ran horribly, had strong raw gas smell from the exhaust, and would just barely pass smog. So I installed the waste gate shim along with a boost enhancer (raised the boost slightly to 13psi) and now it runs unbelievably strong. Way faster than stock. And it passes smog easily--I couldn't believe the difference in this factor.

So you might want to research what chips you have and see if they need a shim or banjo bolt. On the other hand, you should definitely make sure that there's is no shim or banjo bolt in it now as someone else mentioned. You don't want to be running any higher boost with the stock chips.

That number you mentioned (95187) sounds familiar--you might have Weltmeisters also. Not sure though. Some other listers should be able help in identifying what chips you have. So don't give up on the chips you already have just yet.

MichelleJD

It may also be that the owner that installed the chips had other mods as well. He may have yanked the mods when he sold it, but left the "modded" chips in. If the chips were burned for a higher boost, they'd certainly run crappy on a car restored to stock.

951Porschiste

Car has regular cycling valve, no banjo bolt, and AFAIK no WG shims. The only difference is that it did not have the stock airbox. It has the K&N cone filter just behind the radiator (Yes, I know about that location just sucking in warmer air. I'm planning to go back to stock airbox + snorkel).

TheRealLefty

Having purchased a four owner 951S I can testify to the mysteries of Previous Owner mods I've got the OE chips in the car and running well once I figured out that P.O. #2 had installed a dual part waste gate but pulled the boost controller before selling to P.O. #3. This all left P.O. #4 in the dark...although he struggled the car through the air police by pulling the gas smelling aftermarket chips, not even knowing about the evils of the unregulated dual port WG.

As Owner #5 I'm righting the ship and regaining control over The Boost...with Lindsey MBC, mechanical boost gauge, a/f ratio gauge and billet adjustable FPR. But late at night when all is quiet, I can still hear those mysteriously labeled Protomotive 1997 DME and KLR chips calling out from their plastic case out in the glove compartment. "Try me....try me." they seem to whisper

azmi951

I have the weltmeister chips and they say "weltmeister" on them as I recall. Go Vitesse, I rode in a car with his chips and they are soooooo good. Way better than my chips.