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View Full Version : The anatomy of a 12.62 108.45 pass...


RobAGD
03-10-2008, 01:05 AM
OK I had a rather good day at Maryland Internation Raceway to day we were blessed with some out standing air. I was kind of rushed so I was not in my typicaly fighting trim but I fought the good hard fight and here are teh results.

For those that don't know my Goal was to have a 12.99 time slip last winter before breaking into my motor. Everything was there for it except traction and 60ft's ended up with a 13.07 at 104 and change.

I scored some heads and a cam from some buddies ( Thanks BBH and Big Bob ! ) I got tuned at McNews Automotive in Pa and I put down 342 hp and 365tq ( that dyno is very stingie )

So I grab the BGF's and head to the track for a Midday madness, I got to the track and they were running open sessions and knowing I needed to practice how I made the car leave I just emptied the car out and bolted on teh DR and went to town.

Race weight was 200# more than normal for me at 4430# keep that in mind.

Here is a list of my passes :

http://www.robagd.com/cars/robs/sc/DH/mir/03-09-08/MIR-03-09-08-Runs.png

Now if you will look I have several of these passes data logged. I use the DashHawk as it is easy to look at and read and I like the graphing tools. The predator can get me more data but its harder to work with for something like what I am doing. So Here are my data logs

http://www.robagd.com/cars/robs/sc/DH/mir/03-09-08/DH-log1-pass1.png
DashHawk Log 1 Pass 1

Launch at 1800
1/2 Shift 6432
2/3 Shift 6297

KR at
1800 on load .5* in First
3750 1.0*
on shift 4556 2.0*

Timing in 1st - Max 29 low 14 w/ KR
Timing in 2nd - Max 29 low 14 w/ 2* KR ( would have recovered at 16 )
Timing in 3rd - Max 24 @ 4323 Low 17


http://www.robagd.com/cars/robs/sc/DH/mir/03-09-08/DH-log2-pass3.png
DashHawk Log 2 Pass 3

Launch @ 2228
1/2 Shift- 6000
2/3 Shift- 6191

KR at

1* in 1st @ 3160
.5* in 1st @ 4740
.5* in 2nd @ 4834

Timing in 1st - 14 low 27 high
Timing in 2nd - 16 low 28 high
Timing in 3rd - 17 low 23 high



http://www.robagd.com/cars/robs/sc/DH/mir/03-09-08/DH-log3-pass5.png
DashHawk Log 3 Pass 5

Launch @ 2971
1/2 Shift- 6184
2/3 Shift- 6348

KR at

1* @ 3571 in 1st
.5* @ 4405 on shift to 2nd

Timing in 1st - low 14 ( 1* KR ) 28 High
Timing in 2nd - low 17 29 high @ 6271 then drop to 27 @ 6348
Timing in 3rd - low 18 24 high .5 HR

Weird throttle things going on, maybe a slight bumpof limiter ?


http://www.robagd.com/cars/robs/sc/DH/mir/03-09-08/DH-log4-pass6.png
DashHawk Log 4 Pass 6

Launch @ 1750
1/2 Shift - 6301
2/3 Shift - 6405

KR at

1.5* @ 4929 in 1st

Timing in 1st - 14 low 29 high
Timing in 2nd - 16 Low ( w/ 1.5* KR ) 30 high after weird throttle stuff
Timing in 3rd - 17 low 24 high

MOre weird throttle things


http://www.robagd.com/cars/robs/sc/DH/mir/03-09-08/MIR-03-09-08-Predlog1-pass7.png
Predator Log 1 Pass 7

1/2 Shift- 5099 ( short shift on red light )
2/3 Shift- 6367

Launch @ 3059 ?

KR at

4780 in first 2.0*
4942 in second 1.0*


Timing in 1st - max 20 ( short shift ) low 14
Timing in 2nd - 28.5 max 13.5 low
Timing in 3rd - 17.5 low 25 high

some TB / TM stuff going on

Higets injector pulse widths seen 14ms ( or 14000us )


So there you go some basics on these runs, a look into whats going on and what my next steps are.

I have to work on several things in the CMR tune, Launch timing is coming up, some VooDoo I am working out, I need to get some more weight off the car, the goal is an even 4000# race weight, so I know where I had 200# in the car today and I have planes that should get me the other 200#. There is a SLIM chance I maybe able to take an addition 100# off through some light weight parts availability.

I am getting bigger tires ( 275 45 17's ) on a lighter wheel and some front runners and all of that is parts of the diet that car is going on.

-Robert

t500hps
03-10-2008, 08:52 AM
Congrats on the passes (looks like your pretty consistent too!)

PaCharger
03-10-2008, 08:58 AM
Rob - not sure KR at a shift point is really KR - but rather a false read/false knock. If we tunes these cars properly (safely), then turned Knock Sensors off might be a good option.

gotls1
03-10-2008, 12:57 PM
Hey Rob, nice runs! Just a quick comment on your "weird throttle" stuff. Back in CV's post-heads/cam, pre-stroker days, I would notice the car bogging about mid-track after the 2/3 shift. The general concensis was that HAL was mucking around, but it broke before that particular issue could get sorted out. I think the next step was going to be removing fuse 17.

Probably not that helpful, but at least you know it's not just you. You could always do CV's fix and take 10 months to do a stroker. Just make sure you have the car shipped out to SVS for Bob to tune. :mrgreen:

-M

RobAGD
03-10-2008, 01:14 PM
Lol M

My current issues seems to be, being very soft on the leave. It just kind does the
"Oh hey, you want to to good fast now ? Are you sure.. Ok RAWWWWWWWW"

So I am going to have a little work on timing and maybe tweak a few other things.

-R

mcshocks
03-10-2008, 05:00 PM
Congrats Rob, looks like some tuning woes, given due time with your knowledge and patience I bet you'll be chasing down the top 5.7 times. Gotta be happy about the 12's out of the box though :thumbs_u:.

RobAGD
03-11-2008, 02:08 AM
OK put together a little Diablo walk through. Its real basic and I need some more work on it but it gives you an idea of what I am looking at.

Predator Log Walk Through (http://www.robagd.com/cars/misc/predlog/)

-R

BrilliantBlackHemi
03-11-2008, 05:21 AM
Rob - not sure KR at a shift point is really KR - but rather a false read/false knock. If we tunes these cars properly (safely), then turned Knock Sensors off might be a good option.

Doug, let me say, turning off the Knock Sensors is never a good option...tuned or not. :doh:

PowerWagon896
03-11-2008, 05:29 AM
Doug, let me say, turning off the Knock Sensors is never a good option...tuned or not. :doh:

Just NOT worth the risk is it?

PaCharger
03-11-2008, 05:52 AM
Guys, if the tune is perfect, there is no need to turn them off.
What is becoming increasingly evident after watching a lot of hours on the dyno and a lot of passes at the track, is that we have some false knock creeping through the harmonics and shift points of these motors.

I am NOT advocating the "open the diablo out of the box, play with + and -, goto the track, add spark, lean up, turn Knock Sensors off and try to go faster. We know where we've been bitten in the past.

I am advocating there may be something to having a safe tune, chasing the phantom knock that many know I'm speaking of, turn sensors off once you've gotten to that safe happy place, making some add'l logs and passes, spot checking the 1 cylinder spark for detonation, etc...

But hey - what do i know, I have a 13 sec slow pokey car. :)