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Re: JK 24v 3liter ..at last!

Posted: Sat Apr 28, 2012 11:04 pm
by Jim K
...Amused is not the word I would use at this point...'Pi$$ed-off' maybe?
I have a set of bigger new intake valves (37mm vs std 35.6mm) with which I can try to PQ the spare heads. Half of the exhaust valves can also be made a bit smaller and the seats can easily be recessed...
All that's needed is the urge... :roll:
Jim K.

Re: JK 24v 3liter ..at last!

Posted: Sun Apr 29, 2012 3:15 am
by Duk
The results of a pair of PQ heads would make some awesome reading!
Hmmmmmm, a new book for you, JK (ducks, weaves and other Matrix moves! :P )

Re: JK 24v 3liter ..at last!

Posted: Sun Apr 29, 2012 5:27 am
by Jim K
I may just try this on the heads for my proposed 3.2liter. Don't know when I'll get around to it though. Now that the 24v is up and working, its time to continue with the serious 1.8T.
Since I mentioned the 1.8T, here's something you may find interesting: Along with the two 3liter 75's (24 and 12v) I brought the 1.8T (with the new GT2854R) to the track weekend also. All cars have: comparable RSR suspensions, Toyo 888 tires, poly-bushed, big brakes and the same 1.8T 'boxes. The 1.8T with 210hp was just ~2.5" behind the 24v. Cornering behavior of this 4cyl was definitely better as the V6 understeered -no matter how you cut it. I can only imagine what the 1.8T can be like with 80 more hp and gobs of torque... One nice thing is it won't have to rev to 7500 to haul a$$. This will remain to be seen.
Another interesting exercise I did on paper is to see how the 24v 75 has to be geared to approach the 147/156 gta ratios... Well, what will make for almost identical overall ratios is using the box from the 1.6... :shock: Of course, there's no 6th gear, so the top end is limited; the 1.8T box has a 3.91:1 diff and the 1.6 has 4.56:1. Someone out there able to stuff a 6th gear in it? 8)
Jim K.

Re: JK 24v 3liter ..at last!

Posted: Mon Apr 30, 2012 10:27 am
by Maurizio
Someone out there able to stuff a 6th gear in it? 8)
I 've ones heard that it can be done, with sacrificing the reverse gear.... :roll:
(had colloti in my mind, but isn't mentioned on their site)

Re: JK 24v 3liter ..at last!

Posted: Mon Apr 30, 2012 5:22 pm
by Duk
Just need to stop mucking around with Alfa transaxles and get that Tremec T56 based jobbie from a C6 Corvette in there. 6 gears and they survive behind blown 6.2ltr and NA 7ltr engines.
Get a 4.1 diff ratio and a plasma cutter to make the trans mission tunnel big enough, outboard brakes and there you have it, 1 bullet proof transaxle! 8)

Easy :wall:

Re: JK 24v 3liter ..at last!

Posted: Mon Apr 30, 2012 9:32 pm
by Giuliettaevo2
The new Nissan GTR also has a transaxle that might be worth looking at. :wink:

Image

Re: JK 24v 3liter ..at last!

Posted: Mon Apr 30, 2012 11:23 pm
by Jim K
Its a pity the Hone-o-drive unit (Hone Overdrive) from the 70's is not around any more. It would be an excellent fix for many such applications. When it was made -if I remember right- it cost ~$350 and was definitely worth having. Another similar contemporary mechanism was the overdrive unit used in British Leyland cars (MG's etc) but this one was not meant to handle gobs of torque like the Hone. Proposals like other transaxles, although technically interesting, mean considerable cost and cannot be considered as real possibilities at least here and now :(
Jim K.

Re: JK 24v 3liter ..at last!

Posted: Fri May 18, 2012 4:53 pm
by slyalfa

Re: JK 24v 3liter ..at last!

Posted: Sat May 19, 2012 11:23 am
by Jim K
Yeah, that's it!! 'Seek and you shall find'....Nice stuff, definitely made from ...Unobtanium :(
Ok, here's something for you management geniuses: for some reason, the 24v engine does not have fuel cutoff during throttle lift-off. In the track it made for some spectacular shots during shifting, when big flames shot out the back (injectors kept spraying and when the throttle opened again...boom out the exhaust!). Same thing with the spare ecu. Hmmm, this engine was in a 4wd car and the ecu received some inputs from abs and viscomatic circuits. Note that there's no TPS, just a potentiometer with no position adjustment slots ie fixed position. I do have a homemade cct to insert which will cut fuel off on lift-off, but that's not the point; I would like to know how the std 164Q4 does it! Any ideas? :idea:
The pic is from close to the end of the long straight with ~125mph during braking+downshifting.
Jim K.

Re: JK 24v 3liter ..at last!

Posted: Sat May 19, 2012 12:19 pm
by kevin
Fricken awesome pic for the screensaver . We make those flame throwers out the side for anticarjacking here . :D
I will ask the gurus here on that issue .

Re: JK 24v 3liter ..at last!

Posted: Sat May 19, 2012 12:30 pm
by Mats
Why nor working on the parts you know are a bit strange? Like the non adjustable TPS...

Why are you using a stock ECU? Have you asked your dyno guy if he knows something about it?

Re: JK 24v 3liter ..at last!

Posted: Sat May 19, 2012 12:44 pm
by Giuliettaevo2
The Motronic on the 164 Q4 can also generate failurecodes if i'm not mistaken. You can 'read' this with a blinking light that you should connect between some wires.

But why don't you send Stephan at Squadra-tuning an email? He knows these things inside-out... :wink:

Normally it would be the TPS that tells the ecu to start the cut-off. Do you perhaps have a vacuumline connection on the ecu you're not using? :?

Re: JK 24v 3liter ..at last!

Posted: Sat May 19, 2012 12:46 pm
by Mats
TPS + rpm usually...

Re: JK 24v 3liter ..at last!

Posted: Sat May 19, 2012 12:56 pm
by Jim K
Guys,
The 164Q4 ecu is unfortunately a rare beast. There is no adjustment on the throttle pot (not switch). Apparently when the ignition is turned on, the ecu recognizes throttle zero position and counts degrees from there. The dyno man hasn't seen this ecu before and he is not likely to see one like it again; I asked about the issue but he couldn't help. Maybe the best bet is to ask Stephan. I'll give him a try. Another thought I have, is to check the connections this ecu has in the Lancia Kappa cars (same engine, same management). Since that is a 2wd car, there's got to be something different in the wiring. No vacuum lines anywhere except the fuel pressure regulator.
Thanks for the input!
Jim K.

Re: JK 24v 3liter ..at last!

Posted: Sat May 19, 2012 5:07 pm
by 75evo
JK,

What do you mean no TPS? The newer ECUs use pot based TPS, can't be any different than yours. Only thing I can think of is it is not calibrated to the ECU properly.

My ecu has a TPS cali. procedure. You just give it the max and min position during the setup phase and it will know the exact throttle position after that since the pot is linear.

You need to check with the factory service manual if there is such a calibration procedure. Maybe at full close position the ecu is still registering a throttle that is still slightly open. So it doesn't cut the fuel. Maybe the best thing to do is to ask Stephan, he knows Motronic like the back of his hand.

My car cuts fuel above 2000 rpm at 0% throttle I believe, then turns it back on at 2000 rpm or thereabouts. User configurable.