BadAss SRT-Z - 2.4L / A568 - Update!!!

[BadAssPerformance]

Hmmm.. I used green threadlocker but maybe it was different? Only lasted 2 passes

Since then, been using TIG glue

Maybe a tighter (axially) shaft with less walk would help this too

[turboshad]

MY theory on the matter is that with high torque input there is obviously some relatively high spreading forces which put bearing load on the sleeve. With the helical set this also brings decently high axial forces which are flexing the bearing plate at the other end. So high bearing loads with axial movement repeated a whole bunch of times starts to walk the race off.

That was a long way of saying I agree that a stiffer bearing retainer would help the issue. My gut tells me it's the aluminum part flexing more than the steel part. Probably also worth a quick FEA study when I get a chance.

[BadAssPerformance]

I think that sums it up nicely.

The question is if bearing support plate flexing is all of it or is the "float" of the rear bearing held in by a snap ring allowing the shaft to "float"? A tapered roller on both ends like the input shaft would be better...

[135sohc]

plate flexing and the ball bearing float. Even brand new those bearings have some side-side slop, plus the slop of sitting in the aluminum bulkhead. It all adds up to be 'alot' when were talking in thousands of an inch, multiplied by all the force its trying to resist.

[BadAssPerformance]

Exactly...

[ForzaV12]

Update on 600 lb/in springs on the street... Cruised to the "Fall Color" car show yesterday and it rode well, even over some bumps. I did turn the front to "full soft" before the crusie tho. Some folks might not like it, but I prefer to feel the road. .... and this REALLY makes me want to start on the next project, road race Shadow/CSX

Attachment 34070

Just working my way through this thread, great looking car and engine!!!

[BadAssPerformance]

Thanks Forza!

It is starting to show its age but still looks good in pics

[BadAssPerformance]

Made 4 runs at the Nats on the new 24.5's.

Run 1 Friday time run - Car died puling to line, took forever to restart??? got it going, went 10.90@132.23 spinning through 2nd

Adjusted cam sensor depth

Run 2 Sat Time run 1 - 10.77@134.82 spinning 1&2, broke up going thru lights

Adjusted cam sensor depth

Run 3 Sat Time run 2 - 11.34@132.02 spinning 1, miss 2nd, broke up going thru lights

Adjusted cam sensor depth

Run 4 Sat Round 1 - missed the call, saw cars pulling up to staging, ran over 1/4 mile back to car (I'm NOT a runner) out of breath, got to lanes, ALMOST had abye, but one guy was lurking at the back of th elanes so I raced him... left softer and actually bogged off line and then couldnt catch up, didnt matter, he cut a 0.010 light to my 0.131... tried to catch him but he had me covered well and lifted.... car cut out at ~6500 in 3 and ~6500 in 4th... Hmmm... interesting
11.36@133

...oh well, gotta try to figure out 6500 rpm cutout and tune for 93?

[cordes]

That's great JT. A day without breaking is a day of success, especially with the luck you've been having lately.

[Pat]

Spinning is better than breaking! Sounds like the ticket for drag week.

[Vigo]

Heh, yep, nice update but all i got was "no broken axles".

[Aries_Turbo]

Cool. No axle breakage.

I wonder why the setup has so many issues with cam and crank sensors though. Are you sure it's that rather than something else ignition related. Put a scope on the sensor inputs on the Ecu?

[Reaper1]

It's almost like it's a "dirty" signal. Are the wires going to those sensors shielded?

[Reeves]

Glad to hear no broken axles! How was the track prep?

Also, do you plan to run strictly 93 octane at Drag Week, or some sort of mix of something?

I just found out last night that I CAN get E85 kinda near my work. It's got me thinking.....

I had one start to walk but didn't make it far when I switched FDs. The next made it far enough to cut out the slinger and just start eating the case when I went for my third FD. The last one I used green bearing retaining compound and when I took it apart this spring it was right where it should be. I don't know if that means it worked or if I just didn't have enough miles but the green stuff holds pretty good.

http://www.useloctite.com/filephotos...ions_Guide.pdf

We use the green stuff a lot on bearings at work. Starts out a slip fit, and when the sh*t dries and you realize you put the bearing in backwards, you HAVE to press it out.

[BadAssPerformance]

Thanks guys, yep, no broken axles is good. It was still trying to rip the tires off it too LOL

Cool. No axle breakage.

I wonder why the setup has so many issues with cam and crank sensors though. Are you sure it's that rather than something else ignition related. Put a scope on the sensor inputs on the Ecu?

It's almost like it's a "dirty" signal. Are the wires going to those sensors shielded?

At SDAC it was breaking up badly (anyone who saw the RWD/FWD Shelby Z race heard the twin popcorn machines ) and I attributed it to oil on the cam sensor cuz getting the cam sensor out of the oil seemed to fix the problem. My fix *may* be an issue as I'm not sure how the cam sensor likes to read thru a part of a Pibb Xrtra can? The new issue (which I may have had before) is more of a cut-out than a break up. full throttle, then a brief pause, then full throttle again no issues. It wasn't until last weekend that I figured it to be consistent at ~6500 in 3 and 4.

Next step, I want to see if it will do it free-revving or if it is only under load? I like the idea to scope it but don't have one. With the FAST Classic, it is somewhat ghetto as it actually has to go thru an eDist box to convert the signal between the ECU and the coils. I might need to double check the trigger angle between the crank TDC and trigger vs. the cam sync to see if it is overlapping at 6500rpm / 29psi timing or something.. not sure

Glad to hear no broken axles! How was the track prep?

Also, do you plan to run strictly 93 octane at Drag Week, or some sort of mix of something?

I just found out last night that I CAN get E85 kinda near my work. It's got me thinking.....

Track was prepped pretty well, I actually hooked/bogged bad on the last run.

Not sure, but was thinking straight 93... What's the allowable slow time for the class?

[Aries_Turbo]

At SDAC it was breaking up badly (anyone who saw the RWD/FWD Shelby Z race heard the twin popcorn machines ) and I attributed it to oil on the cam sensor cuz getting the cam sensor out of the oil seemed to fix the problem. My fix *may* be an issue as I'm not sure how the cam sensor likes to read thru a part of a Pibb Xrtra can? The new issue (which I may have had before) is more of a cut-out than a break up. full throttle, then a brief pause, then full throttle again no issues. It wasn't until last weekend that I figured it to be consistent at ~6500 in 3 and 4.

Next step, I want to see if it will do it free-revving or if it is only under load? I like the idea to scope it but don't have one. With the FAST Classic, it is somewhat ghetto as it actually has to go thru an eDist box to convert the signal between the ECU and the coils. I might need to double check the trigger angle between the crank TDC and trigger vs. the cam sync to see if it is overlapping at 6500rpm / 29psi timing or something.. not sure

pocket scope

http://www.ebay.com/itm/2-8-2Msps-AR...item3a65b939d2

id be tempted to swap over to megasquirt but your setup does run super well when its not missing from whatever the issue is.

Brian

[cordes]

Thanks guys, yep, no broken axles is good. It was still trying to rip the tires off it too LOL





At SDAC it was breaking up badly (anyone who saw the RWD/FWD Shelby Z race heard the twin popcorn machines ) and I attributed it to oil on the cam sensor cuz getting the cam sensor out of the oil seemed to fix the problem. My fix *may* be an issue as I'm not sure how the cam sensor likes to read thru a part of a Pibb Xrtra can? The new issue (which I may have had before) is more of a cut-out than a break up. full throttle, then a brief pause, then full throttle again no issues. It wasn't until last weekend that I figured it to be consistent at ~6500 in 3 and 4.

Next step, I want to see if it will do it free-revving or if it is only under load? I like the idea to scope it but don't have one. With the FAST Classic, it is somewhat ghetto as it actually has to go thru an eDist box to convert the signal between the ECU and the coils. I might need to double check the trigger angle between the crank TDC and trigger vs. the cam sync to see if it is overlapping at 6500rpm / 29psi timing or something.. not sure



Track was prepped pretty well, I actually hooked/bogged bad on the last run.

Not sure, but was thinking straight 93... What's the allowable slow time for the class?

Angles nose toward the sky as high a humanly possible...

You don't own a scope?

pocket scope

http://www.ebay.com/itm/2-8-2Msps-AR...item3a65b939d2

id be tempted to swap over to megasquirt but your setup does run super well when its not missing from whatever the issue is.

Brian

I like the four channel job I have. Although I think I'm going to pony up the cash for a decent used bench top model. My quad 4 is beyond laborious to set up due to the world's most unintuitive menu and buttons.

[bakes]

I'starting to think it time to book some dyno time, not to go looking for top power but to get this miss nailed down i know it might sound like $$$ but really when you put all the driving time to the track and test and tune not to find it starts to add up . time to nick it in the ---

[c2xejk]

Not sure, but was thinking straight 93... What's the allowable slow time for the class?

10.80 is the quickest you can run in daily driver.

One change to be aware of for this year, in the case of a rain out, the DD winner will be decided by the most consistent of the quick 32. In the past it had been the fastest...

[contraption22]

I'starting to think it time to book some dyno time, not to go looking for top power but to get this miss nailed down i know it might sound like $$$ but really when you put all the driving time to the track and test and tune not to find it starts to add up . time to nick it in the ---

It's hard to duplicate real world conditions on a dyno. He's probably better off doing street testing.