Stock chips OK with manual boost control?
08-24-2019, 11:15 AM
#16
Three Wheelin'
I have been messing with these cars for 20+ years what I found as an absolute Truth is TRUST A REPUTABLE TUNER. After going through TWO head gaskets in my track car I finally brought the car to RPR Tuning in Maryland. John is an absolute pleasure to deal with and Sometimes You may not like hearing "Lower HP Numbers" when it comes to reliability but as he stated to me "I have never had the phone call where I guy blew up a car that I tuned" I can attest to this... I have been tracking my car with a standalone on it for 3 years now, and it just runs.. and runs. The Tune is so good he even eliminated the Idle Stabilizer Valve for me... and I can say that I have never had a 44 idle so good... He put in a good conservative tune and I always leave DE events with a smile on my face,
What I am saying is that all the mix-match of chips boost ect results in having "NO IDEA" of how they will interact with each other without putting it on a dyno and SEEING it.. ... On my streetcar I have an Autothority chipset with the MAF and a full 3" Ex... That is what it was tested and designed for and I keep it that way and never had any issues in the 20 years Ive been running that system.
Find a Good Tuner and make sure your car will "Live" . I can say that RPR can re-program the stock chips, he still has the programmer for the old eproms if you dont want to go standalone.
Allot of people can make big HP but not everyone can make it reliable and bulletproof....
08-24-2019, 11:49 AM
#17
08-24-2019, 06:13 PM
#18
Rennlist Member
Folks -- if I can tap into the collective wisdom with a simple question. I've made minor mods to an '89 95, going to manual boost control (Lindsey dual port) with a 3 bar FPR and Fabspeed exhaust. With the cycle valve deleted, is there any problem running with stock chips, which are actually Weltmeister Stage 4 chips installed by the previous owner back in 1998?
Without going into detail, the expected source for modified chips has sent chips either failed to start the car, or won't function for more than a day. Major bummer, and the shop that has been performing other work on the car is totally frustrated and wants the car gone.
My question is not whether the stock chips will realize the full potential of the mods, but rather whether they'll cause damage/problems with the cycle valve out of the loop. I'd like to drive (as opposed to tow) the car home, and then finish optimizing engine management myself.
Since I've got two boost gauges and an AFR gauge on board, I don't expect problems, but thought I'd ask.
Thanks.
Without going into detail, the expected source for modified chips has sent chips either failed to start the car, or won't function for more than a day. Major bummer, and the shop that has been performing other work on the car is totally frustrated and wants the car gone.
My question is not whether the stock chips will realize the full potential of the mods, but rather whether they'll cause damage/problems with the cycle valve out of the loop. I'd like to drive (as opposed to tow) the car home, and then finish optimizing engine management myself.
Since I've got two boost gauges and an AFR gauge on board, I don't expect problems, but thought I'd ask.
Thanks.
When people refer to stock chips, they generally mean the chips that came with the car from Porsche/Bosch. Stock chips will kill power if you exceed a preset load level (the so-called "overboost protection"). If you have Weltmeister chips, then those would be aftermarket (not stock) chips without overboost protection. People used to run those all the time with manual boost controllers. You can preserve your head gasket at 12-13psi for a long time, or blow it apart in an afternoon at 22psi. 14-15psi on 93 octane is pretty common. As an aside, I was around when Weltmeister chips were popular, and I don't remember anything called Stage 4. They had a set for the cars with K26/6 turbos and another set for the cars with K28/8 turbos (i.e., the S-spec motors). The s-spec version came with a 3 bar FPR and I believe they both came with a wastegate shim to bump boost a bit. Sounds like you have the k6/8 version, since you have a 3 bar FPR, which is the one you'd want for your car. The system is all inter-related, so you will get in trouble mixing and matching parts without care. When just starting out, it's safest to use known-safe systems, or known-safe tuners/mechanics. There are quite a few out there these days. p.s. Is your AFR gauge driven by a "wideband" O2 sensor? If not, or if you don't know, don't rely on its output for tuning, at all....
08-24-2019, 07:01 PM
#19
That's a lot to unpack. When people refer to stock chips, they generally mean the chips that came with the car from Porsche/Bosch. Stock chips will kill power if you exceed a preset load level (the so-called "overboost protection"). If you have Weltmeister chips, then those would be aftermarket (not stock) chips without overboost protection. People used to run those all the time with manual boost controllers. You can preserve your head gasket at 12-13psi for a long time, or blow it apart in an afternoon at 22psi. 14-15psi on 93 octane is pretty common. As an aside, I was around when Weltmeister chips were popular, and I don't remember anything called Stage 4. They had a set for the cars with K26/6 turbos and another set for the cars with K28/8 turbos (i.e., the S-spec motors). The s-spec version came with a 3 bar FPR and I believe they both came with a wastegate shim to bump boost a bit. Sounds like you have the k6/8 version, since you have a 3 bar FPR, which is the one you'd want for your car. The system is all inter-related, so you will get in trouble mixing and matching parts without care. When just starting out, it's safest to use known-safe systems, or known-safe tuners/mechanics. There are quite a few out there these days.
p.s. Is your AFR gauge driven by a "wideband" O2 sensor? If not, or if you don't know, don't rely on its output for tuning, at all....
When people refer to stock chips, they generally mean the chips that came with the car from Porsche/Bosch. Stock chips will kill power if you exceed a preset load level (the so-called "overboost protection"). If you have Weltmeister chips, then those would be aftermarket (not stock) chips without overboost protection. People used to run those all the time with manual boost controllers. You can preserve your head gasket at 12-13psi for a long time, or blow it apart in an afternoon at 22psi. 14-15psi on 93 octane is pretty common. As an aside, I was around when Weltmeister chips were popular, and I don't remember anything called Stage 4. They had a set for the cars with K26/6 turbos and another set for the cars with K28/8 turbos (i.e., the S-spec motors). The s-spec version came with a 3 bar FPR and I believe they both came with a wastegate shim to bump boost a bit. Sounds like you have the k6/8 version, since you have a 3 bar FPR, which is the one you'd want for your car. The system is all inter-related, so you will get in trouble mixing and matching parts without care. When just starting out, it's safest to use known-safe systems, or known-safe tuners/mechanics. There are quite a few out there these days.p.s. Is your AFR gauge driven by a "wideband" O2 sensor? If not, or if you don't know, don't rely on its output for tuning, at all....
At this point, me and the shop guys doing the head work are just interested in me getting the car out of their shop -- I don't consider the job finished without checking out engine management. I don't consider the Weltmeister chip the final product -- it's just what's in the car now.
On Stage 4, it's what the previous owner stated, and what the shop guys read off the chip when swapping for the nonfunctional MAXhp chips. I'm pretty sure (which means not entirely sure) the O2 sensor is wideband.
If anyone can suggest a shop in the Colorado Front Range area that has experience in 944 engine management for slightly beyond stock performance, I'd appreciate the info.
08-24-2019, 11:42 PM
#20
Rennlist Member
If I pull the chips for an upgrade, I'll get you the serial number. Previous owner probably installed the same package as you: Stage 4 chips, shimmed wastegate spring, and the Lindsey "boost enhancer" valve. The shop working on my car recently verified the chip model.
What boost psi you were experiencing when the protection kicked in?
What boost psi you were experiencing when the protection kicked in?
I wasn't watching the gauge when i hit it and don't normally go hard on boost in 2nd gear. Makes for a short gear, lesson learned.
Was likely around 15-16 psi. I'm not running a manual boost controller, so wherever the Welt chip has it set at. It is worth noting, this was 12-14 years ago and the car's still pulling hard.
I sure enjoy the on/off, seat of the pants acceleration of the Westminster chips even though it's ancient technology.
Took a friend out today who owns a 993 twin turbo and he was most impressed. These cars on a slight diet are a hoot.
Good luck with your project.
08-25-2019, 01:48 PM
#21
Rennlist Member
Thanks for the input, Tom. After blowing a head gasket last summer, my intent, as described above, was to first do the non-sexy stuff like cometic gasket, milled surfaces, new head studs, larger radiator and oil cooler, higher flow intercooler, etc. The performance mods were purposely limited to manual boost control of a dual port wastegate -- one small step at a time. The intent was to rely on Lindsey Racing to supply the appropriate MAXhp chips tailored for the small change in engine configuration, but they didn't hold up their end of the bargain -- wrong chips or the chips wouldn't start the car. The point being I had no intention of mixing and matching a bunch of components that weren't integrated -- it's just where the whole mess ended up.
At this point, me and the shop guys doing the head work are just interested in me getting the car out of their shop -- I don't consider the job finished without checking out engine management. I don't consider the Weltmeister chip the final product -- it's just what's in the car now.
On Stage 4, it's what the previous owner stated, and what the shop guys read off the chip when swapping for the nonfunctional MAXhp chips. I'm pretty sure (which means not entirely sure) the O2 sensor is wideband.
If anyone can suggest a shop in the Colorado Front Range area that has experience in 944 engine management for slightly beyond stock performance, I'd appreciate the info.
At this point, me and the shop guys doing the head work are just interested in me getting the car out of their shop -- I don't consider the job finished without checking out engine management. I don't consider the Weltmeister chip the final product -- it's just what's in the car now.
On Stage 4, it's what the previous owner stated, and what the shop guys read off the chip when swapping for the nonfunctional MAXhp chips. I'm pretty sure (which means not entirely sure) the O2 sensor is wideband.
If anyone can suggest a shop in the Colorado Front Range area that has experience in 944 engine management for slightly beyond stock performance, I'd appreciate the info.
Sounds good. Odd that the car won't start on MAXhp chips, since the fueling and idle shouldn't be that different among chips... No disrespect to the MAXhp chips, and I know they have a loyal following, but for your current mods, I'd be comfortable with the Weltmeister chips for the purpose of getting the car home, etc.. The notion of ordering chips tailored to the changes on your car, which are pretty minor and typical, is pretty dubious to start honestly. That's what tuners do.... I'd say the Weltmeister's are as good as any for your purposes, but I'm still curious about the "stage 4" thing. I've never heard of that from Weltmeister, and my only concern would be if they made a more aggressive chip with lots of timing advance, etc. and didn't advertise it to the masses. I think I would have heard about that, but you never know. Is there a serial number or other ID on the chip?. If they are the standard Weltmeister chips that were popular in the day, then I'd say they are fine. Bottom line is that you are shooting in the dark unless/until you either confirm what they are and/or change them for something you can trust. I'm a big and vocal fan of the Vitesse Racing chips, so that might be something to consider too...
08-25-2019, 02:27 PM
#23
I'll check on the stage 4 thing.
08-26-2019, 01:36 AM
#24
Rennlist Member
Chip Spec on my '89 turbo (wish I had taken pictures of them)
Weltmeister Chip Set 1992
CARB E.O. #D-176-7
TC-8220 / DME & KLR
Weltmeister Chip Set 1992
CARB E.O. #D-176-7
TC-8220 / DME & KLR
08-26-2019, 12:07 PM
#25
Three Wheelin'
