Porsche-O-Phile

Hey, I picked up a set of 15psi Weltmeister chips and would like to adapt these to my otherwise stock 951. I've been told that this will require a manual boost controller although I personally want to keep the KLR system "in the loop" and keep things electronic - I can't stand the thought of a manual controller. Since these chips include one for the DME AND one for the KLR, is this just an "insert-and-go" proposition or do I need to invest in something like a Tial / Afterburner setup or something just to use them?

Ian Carr

I would recomend getting a boost controller just cause you do not want to over boost your car with the new chips in. The accur boost control installs in only a couple minutes and is really accurate and easy. Me not having new chips yet i couldn't tell but it seems like it would make sence.

pk951

If you keep the CV in the system you may run rich at higher RPM's with those chips.

My Swiss had those same chips, and running through the CV he was rich 10.1 or so. BY the way he put down 240RWHP with those chips with 3 inch exhaust stock WG at 12.5PSI. So with manual BC set at 15 PSI possible 250 to 260 RWHP.

Just some thoughts.

Porsche-O-Phile

Very nice. I suppose better too rich than too lean, although obviously you want to get it "right on", which is normally what the feedback loop from the O2 sensor does to the DME. . . Since the overboost protection is provided by the KLR circuit, wouldn't the new chips factor that in and use the KLR / CV to provide the appropriate protection against overboost (i.e. the "cutoff" point would be higher, IIRC it's normally about 1.8 bar - this would just raise it to 2.1 bar or whatever)?

Maybe I'm not understanding the manual boost controllers well enough, but it just seems that one of those going to be less reliable than an electronically-controlled system (see Danno's post about wastegate problems at the high RPMs). It seems like a manual controller is just something else to go wrong - and a rather inelegant solution to the problem. . .

lleroyb

I have the Weltmeister chips, shimmed wastegate still using CV. Life is good. Could be different chips though, these came from Performance Products via PO.

Lou

Porsche-O-Phile

Cool - and no signs of rich running or anything?

Mine are serial # TC-8200, exactly what they should be for an '86 951 (according to Weltmeister's web site). Are yours the same? I'll put 'em in tomorrow and let you know how things go then. My wastegate is also shimmed 4.5mm but other than that the car is stock. Thanks for the tip.

theedge

Why keep the stock boost control? Its less than ideal...

Porsche-O-Phile

Well. . . any mechanical boost controller is going to run you into problems at higher RPMs - that problem is pretty well documented. Alternatively you can go with the ApexI that Lindsey or someplace sells that is electronic, but VERY expensive. I suppose I could get the Acu-Boost controller or something and just figure out a way to control from inside the cockpit. Having to stop and get out of the car, open the hood, blah, blah, blah just seems like a terribly inelegant way to "control" something. Just personal preference on that. I also like that the stock setup gives you knock / detonation protection. No such thing with a manual controller. If (when) it fails, you're getting a milkshake and the joys of a head gasket replacement at best.

alexands

Do you have the Welt Stage II chips with a shim? The reason I'm asking is because you mention in your original post that you have 15 psi chips and it's my understanding that the stage II chips are the highest output they make which, according the instructions, raise your boost to 1.9. By my calculations that's only a little over 13 psi. Could be wrong on my calculations.

I've been told by several Porsche mechanics that there is no way my car would pass inspection with those chips because they are the richest running chips available.

Porsche-O-Phile

I'm not sure about the whole "Stage II" thing - mine are the TC-8200 ones as listed on their web site here: http://www.weltmeister.com/ProductDe...?productID=422

As you can see, they don't make any distinction about "Stage I" or "Stage II" or "Stage III", they're just chips - plain and simple. . .

I actually don't see where it says 15psi either, but that's what the guy who sold them to me said they would handle. I kind of doubt it's only 1.9 bar given that stock spec is 1.75 +/- 0.05 bar. Who would spend $300 or whatever for chips to gain 0.1 or 0.15 bar worth of boost? Also, someone earlier (above) posted about the Welt chips giving about 240 at 12.5 psi, so I'm happy with that for starters if that's all it does. If I HAVE to go with a manual BC to hold higher boost level (like 14 or 15psi) then I'll do that and pick up an Acu-Boost or something (or maybe I'll just save up for that really nice looking sexy ApexI. . . ) but I really wouldn't want to go much higher than that - supposedly the stock fuel injectors run out of supply around 260-270 h.p. so I'll need to upgrade those before I go trying to crack 300h.p. or running higher boost levels.

Jason_86_951

Jeff,
I see you got your parts ok. Those chips came off of "Texasooner's" (Rennlister) car, he was using a Lindsey MBC set for 15psi and it ran great. I would send an email to Danno and ask him, he has checked out the code on Welt's and would be able to point you in the right direction.
Thanks,
Jason

lleroyb

I doubt we have the same chips since mine are for the S spec. engine (turbo). I could go check if it would help you decide. BTW I passed emissions with very low numbers.

Lou

TurboTommy

Porsche-O-Phile,
there's nothing wrong with those chips; just put them in and you're good to go. I had them way back and they're quite good. You do need the wastegate shim(s), which you said you have. You're right; don't change anything with the stock boost controls (except the shim(s)).
However, to really enhance everything, add the LBE (set it around 15 psi.) to give you good mid-throttle boost responce; and it works great with those chips.

theedge

You wouldnt be changing it once its installed. When the chips are set for a certain boost, you generally dont change the boost otherwise you run rich or run lean. Running rich isnt ideal for power, but its not that bad for your engine until you run so rich you wash the walls, and running lean is well.. Uber bad except for a few situations. Boost controllers are inherently a set it and forget it type thing, unless you have multiple maps to allow safe changing of boost. I dont even have the OverTake Boost configured on my Profec, because I dont use it for that exact reason.

And I think the higher RPM problem youre referring to is generally solved by a bleed hole. If you leave the CV in place and use a MBC, you dont need that hole or have any major problems. If you remove the CV and use only an MBC, you need that bleed hole to prevent premature opening of the wastegate when boosting in the higher gears.

Porsche-O-Phile

All very good information. I'll go do some more digging / e-mailing about this. Thanks all, keep it coming!