IcemanG17

Okay.....my thoughts.......

Since this is a VERY early Devek stroker...say 15 YEARS ago....the tuning we have today was NOT around back then....the only thing we could do was DUMP fuel to solve problems..... while it sorta worked....its far from ideal....

Sharktuner allows for PERFECT tuning.....no excuses, no band-aids, perfect driveability on track and on the street.....

IF the owner of the car is willing to spend say, $1k....he can get it sharktuned + dyno tuned all in ONE DAY...have perfect driveabilty, probably pass smog & gain HP with ease.....why not take advantage of this....

I wish there was something like Sharktuner for L jet....I even asked John about it....but since there is NO L jet in europe, he didn't make one....

hacker-pschorr

In reality the way you are going about this can hurt the engine, badly.

The sad thing is you will never understand this, even after it's too late.

Speedtoys

When it blows up, let the owner I'd like dibbs on the lower spoiler.

mark kibort

so, in the world before shark tuners all engines blow up? its not rocket science! how are we going to hurt the enigne?? as long as I dont go WOT, the closed loop system does keep things from geting hurt. plus, did i tell you this engine has been running this way for 50,000 miles now?

So, instead of taking the condecending position, why dont you tell me what YOU would do. how does that sound??

Here is how i see it. once i rule out the valve timing, put an AFR on it and check out mixtures, ill go to the dyno or just use a wide band to see what the mixtures truely are. So, what is going to be too late??? all this talk about doomsday, yet we did the same thing on the racer stroker motor and its running great. the only differnce with this engine is 400ccs.

mark kibort

so smartguy, tells us all how this engine is going to "blow up". you have been watching too many movies!

123

I think that deep down inside, you probably know the answer to that question.

mark kibort

Troll, that was a useful post.

Look, what im looking for is some help to see where to start where to help this guy and this nice 6 liter. im not going to spend any money on it, except for little things that i want to help with, so my questions are really about where to start, what to do. im a little learly to step up the fuel pressure without some type of feedback from a AFR reading. if i was to have built this up, i would have not used such large injectors, given that the target HP was to be in the 330rwhp range. it doesnt have cats on it , it has dual exhaust and it doesnt sound very good. what i mean,it sounds like a camaro or a mustang. is that a characteristic of the dual systems? its very loud with no mufflers, cept the ones before the rear can, which is straight pipes now.
it idles fine, once it is warmed up or warming up. ive pulled all the plug wires to see if they are all firing, and they seem to be. it is smooth at idle.

with closed loop, its almost impossible to "wreck" an engine with this kid of ECU, unless someone has some reasons that i need to consider. again, its been running for over 15 years now, maybe longer and althought the major complaint has been pinging over the years, he has seemed to keep it in check with either race gas, octane boost, or his "increasing" the fuel pressure. heck, he might have been turnign the fuel regulator the wrong way all this time , trying to richen it up. i dont know.

barring a visit from Bill with the equipment, again, im not going to spend any money on it. I just want to do what I can and is obvious to see if if a gross problem is fixed, that the car will run better.

im just puzzeled that the rear pipes can be that black and sooty, almost like mine, when you would think the low fuel pressure would keep things on the leaner side of things. however, maybe its so low , the fuel is not atomizing as it should.

so, if you dont want to help here, just go away and troll somewhere else. its a 928, it has a cool motor, and im trying to help a friend. if you want to do the same, post some info. if you dont, go away and find some other place to make yourself FEEL better by bashing someone else. some of you are like my kids 1st grade friends. actually, they are a lot more polite.

FredR

Mark,

Just out of interest- Is this the dark blue manual example with high mileage on the clock [300k miles?-the chassis not the motor] that Devek had for sale a good few years ago? If so think it was built for a chap called Troy .....??

If it was not shark tuned then for sure Marc would not have let it out of Devek without some form of tuning. If it is the example that I am thinking then I know it was shark tuned by Tom Cloutier [the Powerbroker] before it was sold on- and he got quite a bit more from it and that thing flew. Indeed Susan preferred driving it on the street compared to the White car with its lumpy B1 cams.

Whatever this car is, sounds like there is probably something wrong with the FPR/fuel delivery system. It will be interesting to know what you find but sorting out the fuel pressure problem has to be the first step and then take it from there.

Regards

Fred

RET

No, the car that this thread is about wasn't Troy's......

Bob

brutus

Yes " it has dual exhaust and it doesnt sound very good. what i mean,it sounds like a camaro or a mustang. is that a characteristic of the dual systems? its very loud with no mufflers, cept the ones before the rear can, which is straight pipes now."
Very easy to make a 928 sound like a Mustang. Not easy to get it to make as much horsepower as the Mustang.
If you are trying to tune an engine any engine best to do a compression test and leakdown BEFORE you get much further. If the engine has been rattling on and off for years it easily may have broken rings scored cylinders.

The only person who KNOWS how it was initially tuned would be Marc Thomas you might try asking him.

John Speake

The 928 has an excellent knock control system, with a range of 9 degrees as standard. If you can provoke the engine to audible detonation then you have reached beyond that protection limit.

YOu obviously are a "sensitive" drive who protects his engines, but others may not be so. That engine is at risk !

I have already suggested a cost effective option. Get someone with a ST you provide you with a 30# LH EPROM or PEM. ALso ask them to supply an EZK Eprom with 6 deg taken out at the maximum torque area on the mapping. Then it will drive fine with stock fuel pressure. And be safe, for minimum costs.

Rob Edwards

Mark, if you can source an ST2 in the bay area, I will send you (or Bill, or whomever) a copy of the current (very conservative) fuel and timing maps I have in my car right now, which runs 30 lb injectors. Those maps would be a good STARTING point for you. My fuel pressure is set at 63 psi, though. And I get to 80-85% injector duty cycle at WOT in 4th gear. But I'd guess that my compression (10.7:1) is a lot lower than what you have in that Devek motor. Brutus is right, it would be worth asking Marc Thomas how the car was set up, though if it's been adjusted since, Marc's spec may be just a distant memory.

Bill Ball

NOTE: THIS THREAD DOES NOT CONCERN MK'S STROKER, BUT ANOTHER CAR HE IS TRYING TO HELP WITH.

BUT AS TO SHARKTUNING MK's CAR FOR A MOMENT----
We did install the Sharktuner (THANK YOU, ROB!) into Mark's car and went for a couple of tuning rides (Woooohooo!). The car was performing safely as it was - safe AFR and no knocks. We didn't have facilities to do any dyno tuning for power and not enough time effectively street tune and burn new chips. I tried a few "standard" changes (setting the appropriate injector size, for one), and the AFR's got lean. I puzzled over it for a bit and decided to leave it as it was with the settings Mark had already. Honestly, it ran rather well and had very safe mixtures. I don't think Brendan or anyone else needs to be very concerned about the motor in Mark's car. It's doing very well in a conservative state of tune. Even though Mark may have an approach to things that is unconventional and ruffles other people's feathers, his results are generally OK with me, at least as to the stroker that is in his race car. Don't confuse the two cars. I have no knowledge of this other car and have not been involved in it, and don't have any time to help out right now.

===

Anyway, back to the current car - John and Jim has already told Mark you can't run our injectors on 18 or even 25 lbs fuel pressure. When George was having fuel pressure issues due to cavitating fuel pumps, we could watch the pressure fall on a dash gauge, and as it dropped below 28-30, the car died and refused to run.

Mike LaBranche

Mark has a ton of unconventional pragmatism. F=ma applies to everyone, he just has a different path. Kind of like using a beer can to shim motorcycle handlebars on a bmw...

blown 87

And one just cause I like it.