Why didn't I order a Steve Wong chip sooner?
 

Wow, what a difference in the mid-range of the power band. My car had an obnoxious hesitation right around 3000 RPMs that made it annoying in any normal driving. I replaced the plugs, air filter, fuel filter, distributor cap, wires, and it still persisted.

Well I put the SW chip in Friday and it was immediately gone. The car is so much more enjoyable to drive on the streets as the powerband is far less peaky and far more usable from 2500 - 4000 RPMs.

Overall, the swap took about 30 minutes, the hardest part being bolting the Motronic back down underneath the seat due to the awkward access.

http://i.imgur.com/6w9J78T.jpg

Cool. I have a Steve Wong chip installed for my '87 3.2 motor with 964 cams. I can't wait to drive it and see how it runs.

Nice!

I'd love to see what a difference 964 cams make as well.

SW chip + M&K premuffler / 1-in, 1-out muffler = 211 RWHP (dynojet dyno recently), which is a big increase over stock. Silky smooth torque and hp curves.

Nice.

I have a Monty muffler but a stock cat. I considered a premuffler but didn't want to fool with it with our emissions inspections.

My 87 doesn't exhibit that hesitation. AFM perhaps ?

Even on the streets, I try to keep it above 3K rpm.

Nice!! I've had my eye on an SW chip for a while. Which one did you get, the stock or the pre-muffler one?

Also, and I don't mean to thread drift too much here, this hesitation around 3000, was it persistent or more of a random thing? I ask because my '89 3.2 does something similar, but not on any frequency I can determine. Just sometimes while driving (and it normally happens when cruising for a while) it will start to act like it's missing or hesitating in the 3000-4000 range, and not everytime I drive it. The only consistency is that it happens around the same RPM range, but other than that, I have not been able to figure out a cause (not that I've really looked to deep into yet, getting other issues squared away first).

I try to as well but with long gearing, stop signs, traffic, and lights, it's not always a possibility. A number of other people have noted a similar hesitation and mentioned the chip curing it. Could it be the air flow meter? Possibly, but I'm not going to worry about it now.

Stock.

Yes, this sounds exactly like the issue I was having. It wasn't every time, but occasionally right around 3000 RPMs and it felt like there was a pause with the throttle but with no associated noise indicating something wrong.

I just did 91 octance premuff chip, MK premuffler, and 1 in 1 out MK -- brilliant. same as OP -- can't believe I didn't sooner and as jeff bottman has said to me in the past -- I'm now a bit of an evangelist for this set up. lighter faster and relatively cheap -- what's not to like

Looking at the dyno charts on the SW site, I see many where the torque curve takes a dip around 3K but that happens for both OEM and chipped runs.

http://www.911chips.com/dyno.html

Drop the cat if you can. Just keep it if you need to have an inspection done.
Typically there is no emissions on 30 year old cars but your state maybe different.
Have the SW chip /MK pre muffler with stock exhaust.
So nice.

Overall, the swap took about 30 minutes, the hardest part being bolting the Motronic back down underneath the seat due to the awkward access.


I find it's easier to remove the drivers seat to get to the brain box.

Thanks for the reply. I guess that gives me another reason to get the SW chip, not that I think it'll for sure stop the missing, but with the other gains and possibility of helping out there, there's no reason to not upgrade.

OK, I'm a shameless promoter of Steve Wong chips and M&K products. Here's the Dynojet dyno curves for stock '86 targa, Wong chip, M&K premuffler and 1-in 1-out muffler:

http://forums.pelicanparts.com/uploa...1461033575.jpg

Good to hear another positive response on the chip swap, SmileWavy did mine a few years ago, and wouldnt go back to the standard chip now.
Steve's a good guy to deal with too. :)
A.

One of the best mods I've done for my car a few years back. Immediately noticeable difference.

Why is there is a dip in AFR at 5000rpm?

I did a bursch cat bypass and one in one out exhaust on my 87 911 3.2. I also did the Steve Wong chip this week. Wow, what a difference.....it pulls so much harder in the lower RPM range and the idle is smooth as glass. I had to adjust my idle down 200 RPMs after the chip and I made sure to disconnect the brown wire for emissions ( I guess I have a California spec 911?) I still need to check and make sure I'm getting 100% throttle open when pedal is pressed, but I did a minor adjustment already. Money well spent! I got the 91 octane chip for my setup in case I go out west with it.

I will also say they mailed it the same day I ordered it and it was sent priority mail to my house in about 3 days and I live in Georgia. Great customer service. It came with all the instructions and I feel they went above and beyond when it came to everything.

Is the muffler m+k also?

Aren't you using one of Sal's chips? If so, it would be great to see a comparison.

So you were going to order Sal's chip as expressed in this thread:

http://forums.pelicanparts.com/porsche-911-technical-forum/909963-engine-volume-air-flow-3-2l.html

Peaks or dips that deviate from the optimum targeted AFR of around 13.0-13.2 is just part of the inherent variation that exists between engine to engine caused by such things such as cam timing, valve lash, manufacturing tolerances, wear on the air flow meter, type of air filter used, the make of premuffler and or muffler used, the fuel and percentage of ethanol, sensor variations, etc..... Also at the peak torque region of a motor, where the VE is greatest, usually you tune less ignition timing and/or also go slightly richer to prevent predetonation. The greatest variations on a 3.2 occur after 4500 rpm usually, and just like a rack suit vs a custom made to fit, so if you want to perfect it, you can use the dyno AFR data to reprogram a custom tuned chip specific to the motor. Although in the above example, it's really not necessary and any such tweaking would result in minimal gain

I'll pile on, too :D

Steve Wong chip made the biggest difference to my idle. The stock chip had the idle hunting a bit, and it would die too easily right after start-up. I was also pleased to find my CA wires connected, so a free ~7hp there! Overall the car is much pokier and more enjoyable to run to redline.

I need to race my M5 again to see if the 911 can now beat it with the SW chip :cool:

The SW chip sounds great and I had planned on this upgrade before I get my project back on the road this summer. However, I've also been reading about Sal's chip (and new injectors, etc.). I wonder if there are any comparisons out there to know which approach provides the best driver satisfaction. How did you guys decide on the SW chip? I've read lots of good things so did most of you simply expect this is the best option or was there other things you reviewed and then decided against?

Well there's pros and cons to each. Both serve as a way to tune the car, but they really serve different markets.
SW Chips: Plug and play, easily reversible, use your existing AFM/injectors, custom tunes available, relatively inexpensive if you just want to tune your car, you can order it off a website.
Sal System: Totally new MAF/injectors, totally custom, requires WBO2, lots of time on the phone with Sal, more expensive, burn your own chips, etc.

I'm a huge nerd, so I went with Sal and I'm glad I did. I want to get my hands dirty and learn more about this car. I already have. I'm still in the process of getting my car ready to accept his kit. But I'm enjoying the process more than I would have if I'd just chipped the car, and that's really what I'm excited about.

Sal does also provide just a standard 3.2 upgrade chip and a custom 3.2 tuned chip
without the added cost of a new MAF/injectors, nor needing a WBO2.

I've had a SW chip in my car for about a month now and 'am more then happy. It's a "lightened" 88 3.2 with Fabspeed pre-muffler, M&K 1-in 2-out, went with the 93 octane sport muffler chip. The car definitely had lost some mid with the 2-out exhaust but the chip brought it back to life. The biggest positives I can clearly feel is more low-mid range usability, meaning for example I can now cruise roads in 4th at 3000-3500 rpm and the car now responds very well, feels like what 4500 in 4th used to. The power delivery through the whole range is smoother for lack of a better word and the power feels like it keeps going to redline without falling off. For those thinking it's going to turn your car in to a Turbo, it's not. Best description is it refines the whole rpm range giving you smooth or smoother responsive power where you did and didn't have it before before. Idle has gotten more consistent and letting off the gas in the power band results in a "purring" type decelerating idle that wasn't there before. Looking forward to seeing what it does on the track in those screaming rpm short 3rd gear straights before a corner that there is no time to go to 4th.

You're right Dave, I stand corrected.

Is there comparison data (dyno) for Steve Wong vs Sal's tuned setup?

Thanks for the response. Looking again at the chart, the dip itself isn't so concerning, as it dips towards running richer. What confuses me is why the AFR leans out as the revs climb past that 5000rpm point.

My knowledge comes from turbo motors, where high RPM + lean AFR is a recipe for internal failure. Is this a function of an NA motor being more receptive of such a condition? Or an inability by the ECU to control the AFR with such fidelity?

The air flow meter door basically maxes out at around 5200 rpm so its ability to measure further air flow increases stops. Thereafter the quantity of fuel is dictated by what is preprogrammed in the fuel tables which is addressed either through a chip program already developed to match a particular engine/exhaust configuration, or with custom programming. It is not a problem, as the 3.2 and it's injection system has the ability to supply enough fuel for engine displacement increases of 3.5L and beyond. Different engines hit this max point at 5000-5200 differently so thus the greatest variations occur after 4500 rpm.

With regards to the dyno chart you refer to, as I mentioned, the target AFR at full throttle for a Porsche engine for max power is 13.2 to 13.0. That engine is not leaning out after 5000, but went slightly rich to what looks like about 12.6 at 5000, and going back up towards the target ideal of 13.0-13.2. So there's nothing to be concerned about. Generally on a n/a motor, full throttle AFR variations between 12.5 and 13.4 have very little influence on overall power output and reliability as that is the top of the bell curve. Maybe 2-3 hp at the most. If an owner want's it tweaked to perfection, then fine tuning the chip from dyno AFR data is an available as a custom option.

Steve,

Can other providers of AFM's like VEMS or others plug and play with existing Motronic or do you need their specific ECU too for it all to work right

Also, the dip between 2500 and 3K could be what the OP was experiencing ?

Actually having just bought a chip only from Sal he told me he's getting away from that and going more to a custom setup with injectors and chip or chip, injectors, and MAF. Regardless which direction you go, chip only or other solutions, Sal STRONGLY recommends a WB02 to make sure the car is running properly prior to installing any of his parts. Another big difference is, Sal will not just sell you a chip and you install it. You send your DME to Sal, he goes through it and flows any questionable connections, converts it to 89 spec if not done already and then installs the chip. I liked Sal's approach to tuning since it starts with making sure the car is running as it should before installing a chip. I'm not saying Steve doesn't do that also it's just what my experience was when dealing with Sal. Steve very well could have a long checklist you go through prior to selling you a chip I don't know.

As to Dyno charts. I hope to be taking my car to a dyno and will try to post results in my thread.

Just a question about people using a SW chip to correct idle problems. Is this just masking the real issue? The 911 obviously did not have idle issues when new. So, is the SW chip just a band aid for whatever is causing the idle issue?

Another dumb question. In other cars, people replace the AFM/MAF all the time. Why does this seem like a very rare thing on a 911? I bet the majority of us are using the original AFM. In fact, you can barely even buy a replacement AFM if you wanted one. Is it a different design than modern MAFs that get replaced all the time?

I would guess if you told Steve you were having idle issues he'd suggest looking into that before installing a chip. But I'd say you are absolutely masking a problem. I know my car idle searched and it wasn't until I went through everything including setting base idle mixture that things cleared up. Once I had things working the way they should I had a chip put in my car.

Yes, i can compare both, and it would be very interesting.

I have a steve wong stage 2 chip that i bought for my car before i realised i needed a rebuild. It was for ssi's (which i had) and was off the shelf stage 1 before i paid to have it upgraded to stage 2. I never did get it dyno tuned as i had my car back on road at the very end of the season last year after an extensive rebuild. My car was running well, but quite rich (i have a wideband). Like up to 10:1 on wot. Not to get into details, but SW gave me some advice. I am back at trying to figure it out.

Now, a PO had fiddled with my afm. I fiddled with it a bit also, and improved things a bit, but over the winter, I kind of took a left turn and got Sal's maf/chip/injector setup. I had no issues with sw's product, and again, have not yet had him dyno tune it in so I cant say much. I first need to confirm my engine is 100%. I dont want sw to be tuning around an issue that we both dont know about. I will get the sw chip dynoed and tuned-in this year because i am keeping my stock injectors and afm, and I doubt he would appreceate me calling him up 10 years post purchase to have him dyno tune his chip. I got mine in the fall of 2014.

So i can compare sw/afm to sal/maf. I am going to compare a stock 89 chip/afm to sals chip/injectors/afm to sals full maf setup. All dynojet, all same day. I will post a thread on it. However, i will not be doing/sharing the sw vs sal dynos. They are both outstanding members of our community, and both have treated me well. I know sw does not piss in people's cerial, and nor does sal. Nor do I.

I have no intention of steering this thread off topic. Steve wong 100% knows his stuff and you can't go wrong with him. And he gave me a lot of good advice. I follow his facebook page and he gets impressive numbers from his tunes that never fail to surprise me. He also has a mind for safety and reliability which is key. I fully believe in supporting good people in our little hobby. I just went in another direction for different reasons. Partly because i geek out on tech, and had injectors and an afm of questionable tune. When i thought about replacing/refurbing them, the cost/benefit analysis changed a bit. Sal is a great guy too, just like steve. Two very good folks.

Thanks for the very helpful info. In reading some forums, many of us over the years like myself have
understood that tweaking the AFRs was critical to achieving peak performance for a fully stock 3.2 911
engine, e.g. stock exhaust/CRs. If it's not the tweaking of AFRs that help improve performance,
how then can chip tuning increase performance even at middle range?