CJ intake +a6+first couple of passes

[EJR]

love the above comment .. and people were laughing at me saying 430's are not the way to go.. I cant wait till Friday so I can show what my car can do with 430's , CJ and 7700 shifting :rockon:

Its all relative to the cars setup. 4.30s would work better with a tighter converter. 2 different, but effective, paths he can take.

 

[nordy racer]

Its all relative to the cars setup. 4.30s would work better with a tighter converter. 2 different, but effective, paths he can take.

I just had a 5c installed so hopefully it will work...

 

[Justin81]

Just out of Curiosity, What is the RPM range of the current 4C converter you're running. For the tune to show you left at 3200 that's a brutal take of in a 7500+ RPM Car. You can add about 1500 RPM's to your foot brake launch to get a general idea of where the true stall speed of the converter is. If the converter is 245mm based than you may not be able to go much looser with it. Maybe another 500 RPM's. I would have that converter loosened up before you touch anything gear related. The Converter should always be the most important factor after the motor as it needs to harness the Relevant RPM range and apply it to the track. Gears are a fine tuning tool that should be adjusted when the motor and converter are a 100% match. If you can get the car to leave closer to 4000 and add some gearing you'd probably have a 10 second car. Dropping 2400 rpm's at the shift needs to get down to about 1500-1000 at the shift.

 

[EJR]

Its too bad you cant get a bit more rpm out of the trans to really dial in the shift points. Might think about locking the converter as well in the top of 4th.

 

[4VFTW]

Dropping 2400 rpm's at the shift needs to get down to about 1500-1000 at the shift.

not possible without changing the trans ratios...4.10/4.30's will help with the recovery though

 

[goat-ee]

Ouch, not what I wanted to hear. The mph concerns me greatly, not a good sign. But thanks to you and all for the valuable lessons being learned.

Shauns idea of possibly not locking converter till later, sounds like a great suggestion too for keeping the rpm spread smaller.

 

[EJR]

Guys with the autos... dont think in terms of shortening ratios with more rear end gear. Thats what the converters for. A converter, IMO, is the most important part of a stalled auto. Gear wont fix your shift extension, it will just bandaid it to rev quicker back into its power band. A converter will actually shorten the rpm drop into the next gear which is the main problem here.

Idk, maybe Im wrong... but all I had in the GM world, were stalled autos... and none of them had A LOT of gear.

 

[Shaun@AED]

Guys with the autos... dont think in terms of shortening ratios with more rear end gear. Thats what the converters for. A converter, IMO, is the most important part of a stalled auto. Gear wont fix your shift extension, it will just bandaid it to rev quicker back into its power band. A converter will actually shorten the rpm drop into the next gear which is the main problem here.

Idk, maybe Im wrong... but all I had in the GM world, were stalled autos... and none of them had A LOT of gear.

Assuming shifting into an unlocked converter, yes.
The current tune is a locked converter from the middle of 2nd to the end of the 1/4 mile.
We may want to test running an unlocked converter till the 1000ft or so.

 

[nordy racer]

Assuming shifting into an unlocked converter, yes.
The current tune is a locked converter from the middle of 2nd to the end of the 1/4 mile.
We may want to test running an unlocked converter till the 1000ft or so.

we are going to be testing that also.. in my current tune we have the car locking up right after the 2nd gear shift.

 

[corysmach1]

Good info hear. Once dialed in it will go much faster.

 

[Justin81]

not possible without changing the trans ratios...4.10/4.30's will help with the recovery though

This is wrong information. I hope you don't make a habit of this.

 

[Justin81]

Assuming shifting into an unlocked converter, yes.
The current tune is a locked converter from the middle of 2nd to the end of the 1/4 mile.
We may want to test running an unlocked converter till the 1000ft or so.

When you say lock the converter are we talking about actually applying lock up? What's the point of doing this at all. My experience is with 2 and 3 speed stuff where locking converters isn't a concern. Unless we're talking about reaching a target stall speed which is sometimes referred to as the lock up point.

Why not make a pass "unlocked " and let it eat? The motor's asking for the RPM's. It's probably not in danger of blowing through the converter.

 

[NickSezz]

It is a little per-mature but we should have all this ironed out this upcoming NHRA season.

JDM Engineering will have a 2013 N/A Cobra Jet competing ; )

Details cannot be made public yet but I will share our R&D when appropriate.

 

[nordy racer]

Good info hear. Once dialed in it will go much faster.

that's why I just installed my new tag on my car this week

 

[SCalla1384]

Funny , I posted this going from stock intake to boss intake. I ran .03 slower in higher DA going to the boss intake, but trapped .6mph faster. Everyone goes yup boss intake is all show stock intake is better. This is also me saying I had to short shift 1st at 6800rpm because of lock out, and I have 3.31's which sucks with an m6 car.

Now that it's a CJ thread, noooo. Now it's a gearing issue. Lol.

But I do agree, switching to 3.31's or 4.30's depending on converter is a good move. Think it'll help a lot

 

[itSSlow98]

I imagine its gonna be a handful to get a 5c and 4.30s to hook. If it does I think we will see some impressive numbers though.

 

[SCalla1384]

I beleive Casper/JPC was running a 5c and 4.10's. Ran 10.7 @ 124 with a 1.5x 60'.

 

[4VFTW]

This is wrong information. I hope you don't make a habit of this.

Really, enlighten me.

 

[EJR]

Assuming shifting into an unlocked converter, yes.
The current tune is a locked converter from the middle of 2nd to the end of the 1/4 mile.
We may want to test running an unlocked converter till the 1000ft or so.

Yes this I didnt know. My experience comes from the GM world with 4l60s and we never locked a converter. Usually when we did, however, it would be at the top of third gear. It always seemed to weigh out that letting the converter slip the car back into its power band on each gear change out weighed locking it and having it bog. But that was LS/LT and 4l60s... Ive never ran a 5 liter with 6R80. So different worlds I suppose. In that case a bump to 3.31s will help... but that doesnt explain why it went slower shifting higher with the CJ. Atleast thats how I read it.

Funny , I posted this going from stock intake to boss intake. I ran .03 slower in higher DA going to the boss intake, but trapped .6mph faster. Everyone goes yup boss intake is all show stock intake is better. This is also me saying I had to short shift 1st at 6800rpm because of lock out, and I have 3.31's which sucks with an m6 car.

Now that it's a CJ thread, noooo. Now it's a gearing issue. Lol.

But I do agree, switching to 3.31's or 4.30's depending on converter is a good move. Think it'll help a lot

Remember what I said when you first put that Boss intake on? The same thing I said to Paul. . Who cares what other people think... when YOU know what you have to do, thats all that matters. You have the clutch and trans issue solved... now slap the 3.90s in and get it done. It doesnt help that your car is heavy, which makes the effects of those lengthy shift extensions even worse. Look forward to seeing it go down the track again

 

[EJR]

My best ET and MPH came with lowering my shift points in each gear. Like 7500 on the 1-2, 7300 on the 2-3 and 7000 on the 3-4. Granted it is a mt82 car with 3.73 and 28" tires. But same day, same track and in worse DA the car picked up with less rpm. The trans gearing may have something to do with that. But I am just not sold just yet that the CJ (on a GT engine) will ET and MPH best with real high rpm in every gear.

I believe Shaun when he says it needs a higher stall and gearing. That makes sense to keep it in the power band more. But I am not 100% sold the CJ on a coyote need 7500+ rpm to get the most out of it. I have only seen a couple people test different RPM with the CJ on the same day and same track.

The CJ makes the same HP from 6800 to 7800. That is great. But look at the formula to calculate horse power, HP=(RPM * T) / 5252. The torque is falling off the higher the motor spins. The RPM in the equation is what keeps the HP number stay up there. So can the lack of torque up in the RPM slow the car? Remember, torque is a measurable force. Horse power is from a calculation based on torque. It gives you an idea of the torque production through out the rpm.

I actually logged the polar opposite of that. I had the best results shifting right at 8k. Back when I was doing some vbox testing, shifting the 3-4 at 7600-7800 netted me a half second slower 60-130 time then an 8000 rpm shift. I did it back to back to back to back testing out just the one 3-4 shift and it was stronger every time. As far as the 1-2 and 2-3, my best 8th mile mphs came from 8k as well.