The lost secret bosch knowledge!

#7

I don’t think that a dyno standard is a good idea. Peak HP and TQ don’t tell the whole story.

But, if these ECUs can be tweaked without cracking the case, then something does need to be done in the rules.

#8

How can you change the tune without even taking the ecu out of the car?

#9

Y’all, you don’t worry about peak hp…what you want is area under the curve, and to get rid of the dip at 4500rpm. You can do that with a chip, but it would have to be tuned to your car. I don’t think a general tune would work.

Dynos at the nats were 150-156…all the same day. Therefore, consider them good numbers. We are racing cars, not dynos. If yours shows 160hp great…but it does not compare with the results at the nats. CB

#10

[quote=“cbullard” post=68297]At nationals most of us only made around 150whp give or take a little. The highest number was 156whp.[/quote]That’s an important point. It’s telling us that the status quo isn’t broken. Therefore we should pause and consider before advocating fixes.

My father used to tell me “Scott, if it ain’t broken, don’t fix it”. Generally when I ignored his advice, I later had cause to regret it.

#11

Highest was 157, lowest was 145

#12

[quote=“Ranger” post=68290]

Or how about this idea?.. Allow everyone to run a chip. Chip’s are cheap, I’ve had a Turner chip and a Dinian chip for sale for $75 for a year at bf.c and no one’s bought them so $$ is no big deal. Knock-offs are available on ebay for beer-money. The only chip that is a little more expensive is to get one that is customized to have the OEM red line.

We can’t stop people from chipping their DME. Anyone that thinks otherwise is wrong. I can put an illegal chip into a DME and you can’t tell. Since that’s the case, why not let everyone do it?[/quote]

That’s what I’m saying.

#13

What about sealing the ecu and/or the port?

#14

What happens if you had what I have and discover mid season that the ECU has a limiter and you need to source a new one?

#15

Fire gear on…

I’ve known about the switch in a 153 and the reported ability to soft switch a 173 (or later) for a long time. But I have studiously avoided mentioning it (or playing with it) because I think that would not be in line with the spirit of the class. And there are other ways to cheat that won’t be caught unless the inspector knows exactly where to look. And if done correctly won’t be caught by a dyno session.

In one sense this is a case where a MegaSquirt with a “standard tune” and data logs could potentially level the playing field with respect to the engine management system. All it takes is a laptop to download the tune and run an md5sum to tell if the tune is “standard”. A peek at the data logs will tell if sensor inputs have been fiddled with.

But really, if the engine is actually legal a proper tune has an upper limit that anyone can reach. And pretty economically. We are racers and want to get the most out of what we are allowed to run. And for the most part we are talking about 20’sh year old sensors and electronics. Fiddling with the parts used can have a noticeable affect on performance. It makes more sense to me (and is probably cheaper) to allow folks to tweak the tune.

Now back to our regularly scheduled programming…

#16

I believe the quick fix would be to unplug you’re speedo sensor.

#17

I believe the quick fix would be to unplug you’re speedo sensor.[/quote]
Only very late DME’s had a speed limiter, in which case disconnecting that input would disable it.

#18

I believe the quick fix would be to unplug you’re speedo sensor.[/quote]

Where do the rules say you can unplug the speedo sensor?

#19

The rules (9.3.13.14.1) allow for removal of the instrument cluster, cruise control, and OBC and allows for use of DME’s that don’t implement the speed limiter. Thus it would be reasonable to say that disconnecting the differential speed sensor, that serves no other purpose than to provide input to those, is legal.

#20

Just richening the motor won’t get you where you want to be. You must dyno tune the motor with timing and mixture…the timing curve is not what you would see on a normal motor. It goes up and down with rpm and mixture. Takes a while to understand what the motor wants. Chuck

#21

I have not looked, but do the rear wheels have individual speed sensors for the ABS? I know on some older cars, the speed sensor in the diff was used to figure out whether the wheels were locking.

#22

Yes, the sensors are in the wheels.

Foglight, Congrats on Nationals. I know it ended poorly but you put on a great show.

#23

There is a speed sensor at each wheel. The ABS on these cars has four sense channels and three activation channels (each front wheel and both rear wheels).

#24

Ok, so disconnecting that sensor won’t temporarily disable the ABS sounds like…

Thanks Scott. Anthony put on the best show. I will post about that in another thread.

#25

[quote=“Foglght” post=68351]Ok, so disconnecting that sensor won’t temporarily disable the ABS sounds like…

Thanks Scott. Anthony put on the best show. I will post about that in another thread.[/quote]
Disconnecting any sensor will disable ABS.

#26

[quote=“jlevie” post=68353][quote=“Foglght” post=68351]Ok, so disconnecting that sensor won’t temporarily disable the ABS sounds like…

Thanks Scott. Anthony put on the best show. I will post about that in another thread.[/quote]
Disconnecting any sensor will disable ABS.[/quote]
Under the right conditions a good sneeze will disable ABS.