Project GLH SRT4

Exhaust Connected

Sun, 25 Jul 2010 20:21:24 -0700

The car was a bit loud with just the open downpipe. Not to mention, the open downpipe was pointing directly at my steering rack. So I finally pulled the downpipe off the turbo and cut it down some, then welded this piece of 2.5” pipe with a 45 degree bend in it to it. Then I went under the car and cut off the old turbo flange and welded this downpipe to that. It all worked out pretty well actually. I’m still learning to use my mig welder, and I’m using flux core wire, but it turned out pretty well. May not be a perfect seal, but it’s good enough for now. And I saved a fortune doing it myself. I still need to come up with a down tube for the external wastegate, but it’ll probably be fine leaving it wide open for the time being.

Driveable

Wed, 21 Jul 2010 20:38:21 -0700

I guess I forgot to update this blog for awhile. hehe, oops. Seems like there are times where it feels like you’re making no progress at all, simply because the progress is so slow. But it all came together recently and now I have so much to post, I’m not sure what I did with all the pictures. I also failed to take a lot of pictures that I should have. It’s really nothing that I haven’t posted before, for the most part, because I’m just putting the car back together.
I had a list a full page long of little parts I needed to buy/order before the car would be done. I sorted them out into steps.. “These parts to get the engine started” “These parts to get the trans working” “These parts to get the car moving” etc etc.. And as money allowed, I bought the parts and installed them.

Prepped and ready for install

Sun, 30 May 2010 20:37:55 -0700

Spent some time getting the engine ready to go into the car this weekend. I started with bolting the trans up to the motor, so that I could crank the engine over on the starter to prime the oil system. I did it without the cams installed first, cranked it for about 30-45 seconds before it finally got oil up to the head. Then I installed the cams and the timing belt so that I could crank it over till it got actual oil pressure. With that done, I moved on to installing the little odd and ends, like the water inlet tube, alternator bracket/alternator. Came up with a gasket for the intake (oddball bolt pattern that doesn’t match the head or the intake quite right). Tapped a couple of the unused holes in the intake so I can install pipe plugs in them, before I installed the intake for the last time. But generally, just a whole lot of minor things.
You may have noticed that transmission has a large number of wires coming from it. I barely mentioned it a couple posts back.. That is a Chrysler “41te”, an electronically controlled 4 speed automatic transmission.

Building the new motor

Sun, 2 May 2010 14:39:52 -0700

That’s the “new motor”.. My friend that helped me put the new rods and pistons in it refers to it as a “Grenade-a-motor”.. In that the way we did the “rebuild” in his driveway, it’s got as much a chance of grenading as it does of working. Needless to say, I plan to change the oil after running it up to temperature, then do it again maybe 100 miles later, tops. In fact, I don’t think I’ll even hook the turbo oil feed to the turbo for the initial startup/oil.
I think it’ll be fine though, or I wouldn’t be wasting my time on it. :)

The Next Big Change

Thu, 11 Mar 2010 10:12:25 -0800

There’s a whole lot coming up for the 2010 race season. Not the least of which is the “new” motor pictured above, as well as an “uber motor” as I refer to it, which will probably be 2011’s big change.
You may be wondering why a new motor.. Well it turns out, those N/A rods that were in the motor last year just weren’t meant to make more than 300whp.. heh.. Ya know that saying, you’re not going fast enough if you’re not breaking things? This is what I love about turbo’s.. Dial up the boost until it explodes, and turn it back a notch. hahaha..
What happend.. Well I got tired of my manual boost controller not working properly, I confirmed it was the MBC by unhooking the boost reference hose from the wastegate. Suddenly I could get to 18psi as fast as I could press the throttle down. So I installed the boost control circuit in my MS, along with a fancy new PWM frequency multiplier board.. I figured the higher the frequency, the better.. So I set it to the max multiplier of 256, along with MS’s 11khz frequency, I think I ended up something over 2.8MHz.. Needless to say, it turned out the valve didn’t work at that frequency. I dialed up the duty cycle 1% at a time, and kept making pulls. I finally went from 3psi to 18. My overboost protection was kicking in and the car was bucking a bit. I stayed in the throttle hoping it was a boost spike and my boost control would do it’s thing. 2 seconds later I heard a sound that’ll make a grown man cry. It sounded like I was spinning my tires in gravel and the gravel was being flung against my floorboards. It was my engine block. Drat.
I’ve torn the motor apart and done some extensive examination. It was NOT detonation, there was zero sign of that on the pistons, the spark plugs came out looking gorgeous (and actually went into my van at one point where they continue to work great). It simply was a case of too much power, and possibly the overboost shutdown at those power levels being too harsh.. The rods buckled, folded, and in general were torn to shreds. All in the span of about 2 seconds, at that point I pushed in the clutch and coasted with the engine off.
If you remember my dyno plot.. I was making 265whp at 8psi of boost.. So if you figure 7hp per psi, that’s 335whp at 18psi, over 350hp at the crank, and who knows how much torque, 400ft lbs? The N/A rods were intended to make 150hp, and close to 150ft/lbs of torque.. Needless to say, the destruction was epic.. And I have pictures...