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Take 3: Vishnu Tuning Update

28K views 105 replies 53 participants last post by  Celsius 
#1 ·
Those who have been following our progress over the last couple of weeks probably know where we last left off. The last we left off, we control over spark timing, boost control, and some marginal control over fuel. As of last night, we got FULL control over fuel. So, as it stands, we have control over everything we ever wanted to get in control of :)

For those who are haven't been following our progress, here's a little synopsis along with a bunch of dyno graphs.

Two weeks ago, we purchased and drove home in our brand new 335i Coupe (space grey, red interior, 6sp manual). After 75 miles of break in (lol), we brought it to Modacar in Livermore, CA. Although we have a fancy AWD Dyno Dynamics dyno, most people are more familiar with Dynojet readings than anything else. However, Modacar's dyno does read lower than other Dynojets. Running our normal 91oct gas (the best we get in CA unfortunately), our car put down a repeatable 276-277whp and 287-288lb-ft of torque. On other dynojets, the car would probably have put down around 285whp and 295lb-ft of torque (as measured by Automobile magazine, for instance). But since this is the dyno we are using, we're going to stick with these numbers. Just as long as we don't move around from dyno to dyno, all this numbers are perfectly valid and useful for comparing against one and another. Also, all runs were done in 4th and taken right up to fuel cut (~7000rpm)

Stock Run:


After baselining the car, we started our tuning process. We opted to use a slightly modified version of our Xede computer. It is similar to the unit we use for Evos except that it need to read a different crank trigger (60-2 vs 4 teeth) and a T-MAP sensor (0-5 analog voltage vs. Freq wave in Hz). There were also some other sensor differences but we could adjust for that in the Xede software. The first thing we got in control of was ignition timing. We experimented with a lot of different approaches. We found that we could add in timing during cruise to improve fuel economy as well as reduce oil temps. Partial throttle torque was also improved. The next thing we got in control of was calculated load. This had an effect on the boost curve and some secondary effects on fueling. Not nearly enough control as we were looking to eventually get but good enough for an initial stab at tuning. And the results were reasonably good given our inability to control fuel properly.

Results (stock vs. 1st attempt):


So what is exactly wrong with the fuel curve? Check out this Air/Fuel chart:


First of all, feel free to ignore the first 1000rpm of the AFR trace. Tailpipe sniffing widebands suffer from a time delay especially at low engine speeds when exhaust velocity/volume is too low for them to get an accurate reading of what is happening at that exact time. But even looking above 3000rpm, we saw AFRs as lean as 15.5:1. And this under full boost! Lean to say the least. At higher engine speeds, AFR worked its way back into the nice and rich side of things. But the AFR in the midrange was odd. Odd enough to make me look for air pumps which would explain the lean readings. I didn't find any. Obviously BMW tuned this car this way for a reason. Probably for fuel economy and certainly for emissions. Does it compromise power and safety? We won't know for sure until we try something else, no? More on that later on. In our first tuning attempt, we made very very little change to AFR. If anything, our tuning resulting in it being slightly richer at high rpm ("tuned" is the green line, stock is the blue line). But with AFR so lean in the midrange, we really wanted to get full control over fueling ASAP. But at this stage, all most of our gains came from tweaking the timing curve, bumping up boost by ~1psi and eliminating much of the high rpm boost taper. And the results were ok. With this half assed toon...er tune, we picked up over 32whp at peak and a whopping 70whp at 7000rpm.

That was last week. This week, we made some really good progress. Not only did we get full control over boost but we also got every last bit of control of fueling. Yay! This means that we can try all sorts of fuel/timing/boost combinations to see which ones work the best (makes good power with good repeatability, low temps and sufficient knock resistance.) Another thing we did was made a cat-back exhaust system for it. Nothing fancy. Just a one-off prototype that we pieced together with 2.5" crushed bent piping and standard magnaflow mufflers. It replaces the exhaust just after the downpipes. The two factory cats in the downpipe are still in place. But the secondary cats, along with a bunch of bendy exhaust tubing, was all replaced. If we can make good power with this quickie exhaust, we should do really well with a production version offering larger volume mufflers, mandrel bends, etc,. In a way, I wish I had waited to put on the exhaust later and just re-dynoed the car with just our new-found fuel and boost control. But I didn't. So shoot me. We could always stick the stock exhaust back on next week and dyno it again. But hey, I was impatient for a fast car that actually sounded fast :)

With all the engine controls we ever wanted and a new exhaust, the car picked up good power. We limited boost to 11psi for now since we are still running our 91oct pump gas. But with proper boost control now in our pocket (and a 3rd boost control solenoid under the hood being controlled by the Xede), we had a rock solid boost curve with 11psi at 2500rpm, holding flat until 6000rpm and then gently dropping off to 10psi by 7000rpm. Before, during our "first attempt", it would bounce around a little bit +/- 1psi.

New Results
Stock vs. Xede Tuned and cat-back exhaust
91oct


Even compared to our "first attempt", our second attempt with exhaust stacks up well:


However, the biggest improvement we were able to get was with respect to Air/Fuel ratio. Here's an AFR graph comparing a stock car making 277whp to our tuned car making 332whp (green curve):


Yes, the tuned run is running over 2 FULL points richer in the midrange than the stock run! In fact, it substantially richer than the stock run everywhere except 6000rpm where we were able to sneak a bit more power out by running a little leaner than stock.

Still, by virtue of the new fuel mapping, it's reasonable to say that the tuned car is running more knock-free, safer and cooler than the stock car. All while making a boat load more power and torque. All in all, we're pretty happy with the car. It is fast as hell and now sounds nice as well. In first gear, we get virtually no traction at full throttle. In second gear, the car is capable of spinning its wheels as well if the road gets even slightly bumpy. If you drive with the traction control on (yuck), you see that light flash on and off all throughout the first 3 gears :thumsup:

So how much power is left in there? Well, it's clear that we are limited by our 91oct gas. With every 0.5 degrees of timing I sneaked in, the car would pick up a few horsepower. So with better gas, we'll see more power. And with race gas, I'm sure we'll see big gains. But on 93 octane, I'd expect to see another 10whp. We'll probably pick up some more power if we were to eliminate the factory cats in the downpipes. But that would have an big impact on emissions which is something we want to avoid at this point. There are still a few things we want to try out. There's still more power to be had with our current set-up. But for now, I'm just going to beat the tar out of the car and put it through its paces. One step at a time.

There were some people videotaping today's dyno session. I'll try to get a hold of some of that video and post it up. Next week, we're going to bring out our video camera and do some on-the-road acceleration test, pitting our tuned 335i against our 100% stock Porsche 996 and our 100% stock Evo IX. Should be fun! :)

Stay tuned...

Cheers,
Shiv
Vishnu Performance Systems
 
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#48 ·
Hi there Vinsh,
do me a big favor please. I have been following al your posts here and am intrested in this very much. I have a Supercharged E46 now and am considering one of these new twin-turbos:) Can you please take the stock rear wheel off your car and weigh it? I am curious as to how much the stock wheels along with the tires weigh on that car for the front and rear. Yours are run-flats, correct?
 
#49 ·
19" model 230 top the scale at 54.4lbs including the RF tire (rear)
 
#52 ·
Sorry for the lack of updates in the last few days. We just finished running the 24 Hours of LeMons (www.24hoursoflemons.com). We came in 6th place! And that was after losing 2 hours for repair after me getting stuffed head-on into a concrete wall (still sore! :rofl: ) No, not the BMW. We raced a '88 Honda CRX. The Bimmer did make an awesome support/hospitality vehicle though. After racing piles all weekend, it sure was nice to drive home in it.

Back to business.... I just got a PM from a member informing me that there was a software revision to the DME which eliminated the cold start lumpiness that some people (including myself have noticed). I'm going to drop by the dealership tomorrow and see what is going on. If my car needs to get updated, I'll have to hit the dyno again to see what, if any, differences it makes to max power and, if necessary, retune accordingly.

Cheers,
shiv
 
#53 ·
pheeeewwwwwwwwwww glad to hear your ok shiv! :D

im also glad to hear the to project is still on.... the only reason i even visit this forum is for your posts!!! :angel:

like i said before im one of those that is awaiting the end result of the toon' to see if this is the car i want... try and post some videos when u get a chance of the porche v. 335i thanks again for your input, u truley are a genius at work :thumbup:
 
#54 ·
Same....cant wait to c how the 335i transfers the new power in terms of performance numbers 0-60, qurter mile and etc and I bet that porsche video is gonna b one of the most viewed items on this site once its out. My questions r can we install this Xceed ourselves or do we have to run the car over? Does it have a warranty from u guys? What effects does it have on the life time of the engine? Whats ur estimate for the isolated whp of the Xceed with and without the xhaust upgrade that u did?
 
#58 ·
http://www.vishnutuning.com/Files/Vishnu BMW.mov

Note: The video was taken on the way to the 24hrs of LeMons endurance race on a flat road with 2 passengers, a trunk full of racing tools and a tank full of 91oct from Valero. So it's safe to say that it represents the lowest common denominator as far as performance goes

enjoy,
shiv
That thing sounds sweeeeet! :jawdrop: Great job. :D
 
#68 ·
Well in these types of applications, since no one:
a. knows the exact limits designed into the transmission, and
b. tests the existing transmission destructively,
in this case it's the first customers that test the medium term reliability of any upgrades. :dunno:

This is a habit enforced by those customers who demand to get the upgrades before the soldering iron has had time to cool, and ignore the small common sense voice over their shoulders. So what's the common sense voice saying? Simple: you got to pay to play. Every time you take one or more of your car's components over the original loads and limits, you can expect wear to be greater and lifespan to be shorter. It may or may not fail while you own the car, but there is no denying the increased wear IMO. :dunno:

Give the tuners a year to put 50k-100k miles on their test cars and they'll have a much better idea regarding the reliability. Let them open the engine and measure wear, and they'll be able to estimate lifespan. Allow them to fry a few clutches, and they'll tell you exactly what it can take and what not.

This is not just limited to chipping - add sway bars for instance and you increase the repeated partial loads on the mounting points, leading to earlier fatigue failures.

And this is not limited to modifications, but also extends to the way you use the car. Drive like my brother in law and you car will see the north end of 200k miles even with wild modifications. Take it to the track 20 times per year and you will see all sort of failures even on stock cars.

It's a give and take game, and you need to be aware of it... :dunno:
 
#69 ·
Points are all taken ADC.

Personally, i don't do that many burnouts. I like to push the car, but my "runs" tend to be 5-60 ( if that ) and using 3rd to pass on the highway. The latter is where i really expect the 3.0T (especially the chipped version) to shine.

I doubt i'll chew up the transmission during my lease period, even with a chip. :angel:
 
#71 ·
Just a thought...if adding significant HP/TQ puts too much stress on the car's systems and components such as the tranny, etc., then why does BMW cover Dinan power mods under the BMW warranty?
 
#72 ·
They don't. :dunno:

It's a common misconception, but essentially what Dinan is saying is that their warranty starts where BMW's warranty lets off. So if you blow your engine because of the Dinan supercharger system, BMW will laugh at you but Dinan will buy you a new engine.
 
#75 ·
IMHO this is a load of crap and just people looking for something to worry about. BMW trannies are extremely robust and some of the best ones out there and failures are extremely uncommon, including in the extensive number of SC and Turbo charged e36's and e46' with some cars pushing close to 600 crank HP.

I am not aware of any chronic problem of drivetrain failures in e90s, which have been common in some Japanese cars, Acura comming to mind. If power mods are "guaranteed" to cause failure you would be seeing failures in stock cars, especially those being driven very hard. Again, as shiv stated, you might fry your clutch and need a bigger one in a 6MT but otherwise I will be shocked if we start seeing transmission failures in modded 335i's.

Don't worry, be happy:thumbup:
 
#77 ·
IMHO this is a load of crap and just people looking for something to worry about. (...) Again, as shiv stated, you might fry your clutch and need a bigger one in a 6MT but otherwise I will be shocked if we start seeing transmission failures in modded 335i's.
So it won't blow the tranny, but it'll blow the clutch?

Let it be known that clutch replacement is a $1500 job probably not covered under warranty. For people like me (or you?), clutch failure may just be an opportunity to get something better, a LTW flywheel and whatnot - but for others it may be an unfortunate, unplanned and expensive event.

Don't worry, be happy:thumbup:
Be happy allright, but keep your wallet handy... :dunno:
 
#82 ·
Upgrade durability

Imagine this: A US spec 633. Engine has a set of JEs in it to drop the c/r to 8.7. Upgraded fasteners, otherwise bottom end is stock. Hybrid Garret turbo. An intercooler that looks like it was the radiator for a Cat D9. Methanol supplemental injection. 32 lbs. of boost measured at the intake plenum. Custom cam and springs to allow for the higher revs.
About 740 lbs/ft of torque at peak.
This car has a Euro close ratio 5 speed stock from an M6. Diff is stock. Same for half shafts, driveshaft, and the mounts. Clutch is from the M1.
It is driven smoothly, but fully. It was used to make a record setting run up Pikes Peak. It ALWAYS sees the redline (7400) every time it is driven.
It has run for 43,000 miles with no mechanical failure. Yes it has had fastidious maintenence. Plugs, tires (many!), fluids changed much more often than the average car. But the basic drivetrain is solid and intact.
A lot of failure is from the yahoo behind the wheel.
 
#84 ·
Imagine this: A US spec 633. Engine has a set of JEs in it to drop the c/r to 8.7. Upgraded fasteners, otherwise bottom end is stock. Hybrid Garret turbo. An intercooler that looks like it was the radiator for a Cat D9. Methanol supplemental injection. 32 lbs. of boost measured at the intake plenum. Custom cam and springs to allow for the higher revs.
About 740 lbs/ft of torque at peak.
This car has a Euro close ratio 5 speed stock from an M6. Diff is stock. Same for half shafts, driveshaft, and the mounts. Clutch is from the M1.
It is driven smoothly, but fully. It was used to make a record setting run up Pikes Peak. It ALWAYS sees the redline (7400) every time it is driven.
It has run for 43,000 miles with no mechanical failure. Yes it has had fastidious maintenence. Plugs, tires (many!), fluids changed much more often than the average car. But the basic drivetrain is solid and intact.
Well we're not talking about the 633 built more than 20 years ago, but rather about the current products of a much more cost-conscious company. :dunno:

A lot of failure is from the yahoo behind the wheel.
Of course, it's probably equal parts hardware and driver. My friend has a 98 M3 with intake/exhaust - say some 255BHP on a good day. The car has been very well maintained, he doesn't do standing starts at all, but drives hard and tracks the car a few times a year. He's around the 70k miles mark and will need a clutch bearing very soon. He doesn't mind really, he sees this as the cost of doing business.

You always have to judge the product in case, any previous examples are largely irrelevent. :dunno:

(and that being said, they don't build BMWs like they used to) :p
 
#85 ·
First of all, let me state that I think what Shiv's been doing is really fantastic. I am very excited to check on this thread.

But realistically, as Shiv himself pointed out, once modding becomes widespread BMW will come down hard on all 335i owners. As a current owner of a Subaru WRX, I know a little bit about owning a car that is on the manufacturer's black list. I strongly believe that one should not start modding under the assumption that it wouldn't be detected. You pay to play, and that should be the base line before you start modding.
 
#86 ·
Which (nothing against Shiv b/c it's obvious that he and his co. are doing some excellent things with the Xede and the 335i) may be a reason to go the "safer" route with Dinan (once the s/w update is ready) since it's something BMW would have no problems knowing exactly what's been modded...you'd have nothing to hide. Your dealer would know and wouldn't care that your car has been updated with the Dinan s/w becauase they themselves sold it to you and your BMW dealer's service dept. themselves did the install. Even if the mod is covered under warranty by Dinan and not BMW per say, it's still the "safer" mod if you're concerned with the warranty and/or any potential problems with your car relating to the mod. :thumbup:

Don't get me wrong, I'll love to slap on the Xede, and I may still do just that, but I also don't want to have to rip out a black box and reconnect wires to the ECU every time my car needs to go in for service, just b/c I'm paranoid that my dealer is going to say something like "well, that thing you put on your car was found by one of our technicians and it's the reason you're having problems...we can fix it (for $3,000 of course) but sorry, it won't be covered under your warranty since you decided to add that engine modification." :tsk: :p
 
#88 ·
regarding Dinan

I think the point with Dinan is that BMW covers BMW parts, and Dinan covers Dinan parts. But the most important thing is that BMW does NOT cancel your warranty with Dinan mods. I don't think that can be said of other companies. As far as I understand, Dinan is unique in that respect.
 
#89 ·
I think the point with Dinan is that BMW covers BMW parts, and Dinan covers Dinan parts. But the most important thing is that BMW does NOT cancel your warranty with Dinan mods. I don't think that can be said of other companies. As far as I understand, Dinan is unique in that respect.
I don't know. It definitely *used* to be that way. But according to what the dinan site currently says, bmw may choose to invalidate the warranty on affected parts. So, if you dialed up the boost with a dinan chip, and blew a head gasket or fried a turbo, BMW might tell you "too bad."

Now, i know some audi dealers would just neglect to mention to audi USA that a vehicle in for chip-related repairs was chipped, especially if the car owner bought the mods from the dealer. But i think audi USA rooted this out as best they could, since they end up paying for all the warranty work.

dave
 
#91 ·
If you think BMW's safety factor on that tranny is only 1 then you need to stay in school.

More like 1.4 or higher. So, more than likely if the engine team told the tranny team that the engine would be putting out about 300 ft-lbs at the crank the tranny team multiplied that by 1.4 or higher (those darn conservative German engineers) when they designed the tranny.

300 ft-lbs X 1.4 = 420 ft-lbs

And that is a low estimate. More than likely they hit that thing with a 1.5 or maybe even a 2.

And by the way, an elevator usually has the highest safety factor at 10 while aircraft have the lowest at 1.15. Thats why the aerospace industry has such high quality control standards vs. other industries... they can't add more weight to make the vehicle stronger.

K
 
#93 ·
If I can still remember my Machine Design 101 subject in ME before I change my carrer to computer. Our Professor was the manager of the GM transmission plant and one of the topic was the design of gears in the transmission box. Each gears has been design differently like the first gear life multiplier factor is less than the sixth and accordingly. The safety factor was around 1.4 mulipying it with the life factor. I even remember that we were surprised that the first gear was deigned for life expectancy of just hours not months or years. But he pointed out that the computation was based on 110% load factor x 1.4 (safety) x 120%Torque x 24 hrs life expectancy. Your first impression is that the design computation is low but he pointed out that how many times you will load your car 110% with torque of 120% and how long will you drive your car in first gear in that condition, which make more sense. It will take years before you reach the designed computed strength for that particular gear. The gears will not break as soon as you reach that computed value but will start to loose some of its efficiency due to change in tolerances in dimensions. The car will still run but you will start to hear some gearing noises, from softly and getting louder, but it will still work without any problem. One last thought that stays in my brain after that session, he said that:Engineers don't design machines for life or else we gonna run out of work to do!
 
#97 · (Edited)
yes running lean may squeeze out more performance but in the long run after getting chipped may cause detonation/pinging etc. Are there plans to replace fuel injectors to increase fuel supply or just reworked A/F maps? Just out of curiosity does anyone know the max torque rating of the ZF 6 speed step in the 335i. Planning on getting one in summer 07 and wanted to know how much the step tranny can take
 
#98 ·
Shiv found out (the first post in here) that the OE map was lean and at the limit of detonating, whereas his tuned map was a lot more safe:

we saw AFRs as lean as 15.5:1. And this under full boost! Lean to say the least. At higher engine speeds, AFR worked its way back into the nice and rich side of things. But the AFR in the midrange was odd. Odd enough to make me look for air pumps which would explain the lean readings. I didn't find any. Obviously BMW tuned this car this way for a reason. Probably for fuel economy and certainly for emissions. Does it compromise power and safety? We won't know for sure until we try something else, no? More on that later on. In our first tuning attempt, we made very very little change to AFR. If anything, our tuning resulting in it being slightly richer at high rpm ("tuned" is the green line, stock is the blue line).

...the biggest improvement we were able to get was with respect to Air/Fuel ratio. Yes, the tuned run is running over 2 FULL points richer in the midrange than the stock run!
...by virtue of the new fuel mapping, it's reasonable to say that the tuned car is running more knock-free, safer and cooler than the stock car. All while making a boat load more power and torque.

Shiv
Vishnu Performance Systems
 
#99 ·
I'm sure the tuners in Europe will have packages coming out soon too for this new 335i:) ECU Upgrades from Europe will vary with power outputs and top-speed delimiters:) I can't wait to get my hands on a new 135i if they ship them to Asia.
 
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