Steve W. says "Your girlfriend is fat, ugly and smells!

[mnmasotto]

I bit the bullit and decided to have Steve Wong (911chips.com) do a custom chip for my Carrera. I figured I would get maybe a few more HP and finally get to see what my fresh, recently rebuilt, modified 3.2L motor would produce. Some of you may have seen my recent posts covering the various mods to my car. My motor was recently rebuilt by Vision Motorsports approximately 2500 miles ago. The P/C's were great. We re-ringed the top end with a "performance" valve job, ported intake plenums, Custom SSI exhaust system from Ben (M&K), 964 cams, Bosch MAF, various ARP paraphanalia, new stock flow fuel injectors, O2 sensor and approximately 3K motor in little bits.
After reading other posts with tired motors putting out over 200 HP at the rear wheels I was hoping to see somewhere in the neighborhood of 205HP. Yeaaaa right!!!!

My car in the parking lot of Vision Motorsports in Laguna Hills, CA. Do you reconize the car next to mine? None other than Palph Hollack of Porsche Motorsports. He has his car wrenched on by Dwain at Vision Motorsports. Actually, Ralph's 3.5L (280HP)motor was part of the inspiration to have my motor rebuilt and modified instead of going up to a 3.6L transplant.



There she is all strapped down and ready to get down to business.




The "Wizard" talking to Dwain (Owner of Vision Motorsports and prior ANDIAL Mechanic/builder)


The bathroom was full but Steve really had to gooo!!!

Just kidding, he is actually messing with some cables.

Steve giving some driving instructions to the dyno operator.


At work!


Here is Steve about to tell me "Wow, your car is only making stock horsepower"
Wait a minute, Stop the presses! "Are you sure Steve?" "Yes, I am sure! She is ugly!
After multiple tuning runs I was able to get no more than 190HP at the rear wheels.

After a test drive the drivability is better and the car idles better. Overall it was a great experience. I recently read three book on Bosch Motronics and ECU tuning. I still know less than 1% of what Steve knows about this subject.

You will not see me in any of the photos because I am sobbing uncontrollably in the corner with a box of Kleenex.

[DYB]

Well I for one think Dyno's tend to be fat ugly and smell

I have had mine done over a period of the last 3 years for benchmarking purposes. The number varies from 130 at the wheels to 185 at the wheels. I have done nothing to the car other than a SW chip and those variations have been with the chip in the car. The car itself should be making 231 HP at the flywheel.

I go to the track and it has no problem matching strait line acceleration with 3.2 911's 915's which I know are up to spec and lighter.

There are many examples that you will come across where these fantastic numbers are claimed but personally I have my doubts.

To me it is all relative. Numbers count for nothing really. The question you should be asking is what is the real life experience of how it drives and how does it compare side by side against one of the cars that are supposedly making 200 RWHP?

As an aside, last time I had mine Dyno'ed, the tech indicated that the G-50 box takes more out of the power generated to the wheels than the 915. Dont know whether that may have been taken into consideration in your case.

[rnln]

Are you saying it drives better but it doesn't gain any HP? How can that be?

[Buckterrier]

Originally Posted by rnln

Are you saying it drives better but it doesn't gain any HP? How can that be?

I think that can be true. The HP or more so the torque, could be moved to a more user friendly RPM band. Just guessing here.
One thing I am curious about though... When the rebuild was discussed were not HP/torque gains discussed? And then because the shop has their own dyno there could be proof in the pudding so to speak.

[ChkbookMechanic]

Dynos in general are a touchy subject. All of them can read differently so you never really know what power you are making. The best bet is doing before and after dyno runs to see how much your performance has increased or decreased based on a particular modification/s.

The big question is after visiting Steve W. and having him remap your chip does your car drive better than it did before?

And we all know this talk is worthless without some dyno numbers because we have to benchmark race .

[mb911]

Great pictures Mark. Did you get my email yesterday? Call me if you get a chance we need to finalize

[84_Carrera]

Stock 3.2L engine ('84), Weltmeister Chip (Have lusted for a Wong chip for years), Fabspeed Euro Premuffler, M&K 1-in / 1-out, Cone filter replacing airbox, fresh 15k service (by me), and +6% fuel on the DME fuel switch. Same dyno over the years, same operator. I have hundreds of pulls over the years so please don't give me the new kid lecture.

Run 11 was done in 2008 after a new clutch & trans rebuild, ~88k miles. Run 1 was done in late '04 at 50k miles, after purchase & the 850 mile ride home, stock cat, stock muffler, same chip, stock airbox, stock fuel setting. Lowest run was with cone, chip, stock fuel, and playing around with exhausts (Bursch, I think was this pull, or it was the Fabspeed muffler bypass, I forget).




I think you have some issues to look through if you've done a performance engine build vs. a stock rebuild.

[scarceller]

I have a 3.2L with very simular setup:

Euro P/Cs
Web Cam 20/21 grind
Port Polished and Flowed intake
SSIs with M&K 2in2out
Still have the stock AFM
Custom chip with much help from Steve W

Here is a old dyno chart for this setup:


I must say something seems wrong with your setup. Double check everything:
Cams properly timed?
What was the AirFuelRatio?
Ignition strong?
Cyl leak down/comp. test?
All plugs and injectors working?
...

Can you post the dyno chart to see what the HP/Torque curves look like.
In my engine it develops max HP at about 6000RPMs, how did yours look?

Also. max HP and Drivability are 2 very diffrent things and are usually tuned individually.

[scarceller]

Originally Posted by rnln

Are you saying it drives better but it doesn't gain any HP? How can that be?

Drivability can improve and HP decrease, this is because the Motronic system has entirely different maps for Ignition and Fuel for WideOpenThrottle and PartThrottle. Drivability is usually improved by tuning PT maps while Max HP/Torque is achieved via WOT maps.

For this reason I agree with the above posts that what really matters is street/track driving. I'm not that concerned about dyno runs these days. I tend to stick to very simple street/track results, for example:

I have full WideBandO2 controller installed in my car that records the following signals:

AirFuelRatio
RPMs
AirFlow signal from the AirFlowMeter (0-5volts)
WideOpenThrottle switch (to be sure when I'm using the WOT maps)
Speed in MPH

I then simply use the same stretch of pavement and pull a simple standing start WideOpenThrottle 2nd gear runs right up to red-line (1000-6800RPMs) no gear shifts here to remove the human error element.

Then I simply look at AirFuelRatio and time to speed meaning how much time does it take to get from 2500RPMs to 6200RPMs. Or speed, time from 30MPH to 60MPH. You get the idea. The only variable is climate conditions, temp and humidity. I can tell you the cooler temps with low humidity produce the best results in my setup.

This type of testing is only good for tuning WOT maps and looking for top performance.

Tuning for Driveabilty is much more complicated and takes many hours/days to do right. I have been fine tuning my drivabilty for over 6months! But of course I'm learning along the way. I'm sure a pro can do this much faster but the point still is it can take much longer to improve drivability than max HP. This is even more true in engines that are not stock such as the engine in this thread.

In the end I have not used a dyno in about 2 years now and may simply return to one out of curiosity since I much prefer street results.

[JeremyD]

Well - you won't get much from the 964 cams.

The bosch MAF is a big question.

With SSI's (which are a little small) you are probably losing some top end HP.

So - yes, it's possible your driveability may improve - and you may have more torque down low - but when it comes to top end HP bragging rights - not much beats long tube big headers and a non existant dual out muffler at the expense of low end torque.

[rsrmike]

You could just have a bad throttle switch, not triggering the full load contact

Or possibly your throttle linkage is a little boogered, did any one check to make sure the throttle body lever was hitting WOT?

[911st]

A MAF system dose not seem to add HP over a well tuned barn door style system from some of the reading I have done. I believe it is better above 5K rpm at keeping the A/F ratios right where the AFM seems to stall out.

JeremyD notes the cams. I suspect the stock cams are will matched to a stock size motor. C2's have more lift and can breath more if a motor can use it but I suspect they are not anymore agressive. Some say they can help higher rpm but your SSI is not geared to support this so it may not help the increase breathing on the intake side if the exaust side is not able to handle it. If it was a bigger motor like a 3.5 the cams might be needed to keep up with the greater amount of air the car would require.

Porsche did a pretty good job out of the box.

Just a thought, I try to run a new air filter when I do a dyno run. If you have converted to a MAP system, verify your air cleaner is not a restriction. I have alwas suspected my cleaning process on a K&N style air filter.

And yes, dynos vary. The dyno owner should have comparable car numbers for you to compair to if you don't have before and after numbers. I have a dyno buddy and we go to the dyno with similar cars at the same time.

In all, sounds like a great car. It will likely get faster as the motor runs in.

[scarceller]

The AFM does indeed top out (fully opens at about 5200RPMs) I can clearly see this in my runs since I log AirFlowMeter signal against RPMs.

I suspect the MAF won't help much at WOT but it most likely will improve throttle response. But be careful here as there are also some tricks to help with throttle response even with the stock AFM. What you need to concider is: what if I first apply all the tricks to help with throttle response with the stock AFM and then compare this to a MAF upgrade? This is a much better comparison.

Also, even though the stock AFM tops out after 5200RPMs the motronic does a fine job of calculating fuel based on RPM alone at WOT after 5200RPMs. So the only other question is how much of a restriction is the stock AFM? This I'm not sure of.

BTW - Steve W is the master of improving throttle response, I know this first hand as I have one of his chips and the biggest improvement over the stock chip is throttle response. You are in good hands with Steve

[dfink]

If you were on a dynojet then I would say you were a bit low for what you have. If you were on a Mustang for example 185 would probably be great. That's one problem comparing dyno numbers different machines calculate different numbers. Ok for tuning same car on same dyno. I second checking for wide open throttles. Last time at the dyno I had mine set to be wide open with no carpet. I forgot to remove the carpet at the dyno and got crap numbers. Thought of it on the way home.
I am one of those who claim great numbers. My stock 85 did 203 (US model) on a dynojet. After top end, 964 cams, CAT bypass and Steve W custom chip - round 1. I only saw 175 on a Mustang. (did I mention carpet issues)

[scarceller]

I have heard nothing but great things about the Dynapack dynos which are true load dynos and direct bolt to the wheel hub, no roller slip.

See here:
http://www.eurotechracecars.com/dyno.html
This shop near Boston, MA has nice pictures online.

[911st]

Sal,

Agreed, a well set up barn door style system can make perfect A/F's after the flapper stalls. However, it becomes mostly a reference system which works great if all is in spec. If something throws things off like changing out the muffler or a dirty air filter then the A/F's can be off under WOT above 5k rpm.

If one builds a 3.5 that breaths well, this stall point will be at a lower rpm.

Not sure how much the MAF conversion will help over our system with throttle response. Increased fuel is near immediate due to the response of the fuel pressure regulator to the loss of vac. I guess the flapper door can creat a bit of restriction.

I am not an expert but I suspect if we want to improve throttle response other than the normal ignition and fueling strategies would be to put a TPS in the system or best yet, get the throttle plate (s) closer to the intake valves.

There is one tuner out there that can convert our Motronic to a MAP style system with TPS. I think this what RUF did with the Yellow Bird. This has potential as it removes the total restriction in the intake manifold. This could also make it easy to convert to Turbo or ITB's with out having to rewire the car and add a bunch of sensors.

I have thought of experimenting with putting a vac loss switch in place of the WOT switch to trigger the WOT maps sooner. I have the switch but have not tried it yet. This could support a throttle response strategy of some type I suspect.

[scarceller]

Originally Posted by 911st

Sal,
I have thought of experimenting with putting a vac loss switch in place of the WOT switch to trigger the WOT maps sooner. I have the switch but have not tried it yet. This could support a throttle response strategy of some type I suspect.

Kicking the WOT map in to early would not be a good idea because the WOT map is a simple 2D map (not a 3D) meaning it only has Fuel/Ignition Values setup for a single condition which is WOT across the RPM range.

So if you kick it in to early you will run way rich, most likely in the low 12s if you kick in the WOT map at say 70% throttle.

I have actually tuned my Part Throttle maps to do what you are suggesting. The idea of improving throttle response with extra fuel is best done in the PT maps not the WOT maps.

But of course you need to burn new chips to do this.

[911st]

Sal,

I am not happy with my throttle response. Steve has improved it but I just don't get the throttle response I need with a down shift.

I have a 915 trans w stock clutch. Have you made good improvement here?

I have to almost count 1001, 1002 before the rpms respond enough for a good shift.

I get good HP at 217rwhp with a stock muffler, chip, and cat bypass. Only disappointment is the double clutching throtle response.

[scarceller]

Originally Posted by 911st

Sal,

I am not happy with my throttle response. Steve has improved it but I just don't get the throttle response I need with a down shift.

I have a 915 trans w stock clutch. Have you made good improvement here?

I have to almost count 1001, 1002 before the rpms respond enough for a good shift.

I get good HP at 217rwhp with a stock muffler, chip, and cat bypass. Only disappointment is the double clutching throtle response.

I'm not sure that down shift would be all that affected by throttle response, but I'm not a pro at understanding shift issues either. Maybe someone can chime in here?

But what I do know about shift issues with the 915 is that often they are the cause of poor clutch/cable adjustment. My car had issues and a simple clutch/cable adjustment fix it.

Our host Wayne has a great procedure for adjusting:
http://www.pelicanparts.com/techarticles/911_clutch_cable/911_clutch_cable.htm

Describe in more detail what the downshift issue is?

Also, it's very hard to improve throttle response in Steve's chips, I know this first hand I have his chip as well. This is why I'm guessing that the issue is most likely mechanical.

[911st]

When double clutching for a track down shift you have to blip the throttle to spin the motor and gears up to engage the gear and again to match the rpms with ones speed to keep the rear wheels from receiving a motor braking effect.

With poor throttle reponse the motor rpm dose not respond to the quick blip and the gear speeds are not well matched for the shift.

To me this is throttle response.

This is different from low rpm torque or pull when transitioning from cruse to acceleration.