Turbo Kit Test TJ
- Thread starter Jezza
- Start date
OP
The kit is progressing nicely. The hot side piping is done and I'm working on the intercooler parts now. It should be close to completion by the end of June or early July.
B00mb00m
The Church of Cutting Brakes of Atlas-Front Digs
Supporting Member
Ride of the Month Winner
Another one following along! @SkylinesSuck and I were just having this conversation yesterday, i.e. big turbos, small turbos, and how to balance the correct one, controlling both lag and spool, with our 4.0l. As @B00mb00m said, the challenge for many of us is the nearly 1K rpm drop we see when the 42RLE goes into overdrive. This results in an RPM range that is often well below 2K RPMs. That said, I'm shallow and just want to hear, from under my hood, the sound of a turbo spooling up again!
I would not worry about setting a turbo to combat the OD dropping the rpms. There are better ways to address that issue.
One push of the OD switch is how most do it (as you know), but I’m very thankful that @AndyG guided me how to make OD auto-off and switchable to turn on when I want it. I happily drive around everyday this way just like having a 32RH but with OD when I want it.
With the 5.38s and auto-off OD my daily driving experience is great. I don’t turn on OD until I’m going about 70 mph which is 1% of my driving at most. Most of my driving is 35 to 50 mph and I’m very happy and never think about OD.
I will be absolutely thrilled if @Jezza creates a reliable set-up that pulls well from approximately 2k – 3k rpms.
Banks discontinuing their turbo really bums me out so I appreciate @Jezza sharing his adventure with us. There is hope.
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Brianj5600
TJ Expert
I've seen a few references to the stroker power band being displaced to higher RPM vs a stock 4.0. Here's my '97 stock 4.0 vs a Golen Stroker in the same TJ w/ an AX-15, 4.10 gears on 33s. The data is from a Mustang dyno. Per Golen's recs the stroker is using the stock '97 tune. To me, they seem fairly parallel on paper and in real life.
That should primarily be dictated by the cam profile. Apples-to-apples, a stroker version of a given engine should produce more power while gravitating toward a lower RPM range. If 4.7 strokers have a reputation for putting the powerband in the upper RPM range, then I would assume that's the builders looking for a hp number for advertisement reasons.
OP
The increased displacement won't be an issue as the turbo is sized on the larger side for the 4.0l airflow. The potential issue would be compression. If the stroker has higher compression it may be difficult to keep spark knock under control.
OP
Can you move it back a bit I have a coilovers brace occupying that real estate
I pushed the turbo back as far as possible, but the AC accumulator is preventing the downpipe from moving back further. The turbo is rolled in towards the valve cover a bit as well. How do the coil over tubes run?
B00mb00m
The Church of Cutting Brakes of Atlas-Front Digs
Supporting Member
Ride of the Month Winner
It's typical for the coilover setup to run a crossbar in this general vaccinity. Mine is basically inline with front valve cover breather. For me in western wa I'd probably sacrifice AC for turbo powah. Or I could probably make a brace that fits like exactly over the turbo intake.
@mrblaine I know you have re routed AC stuff could the accumulator be moved to near the grill with new lines?
would it be easier to modify your brace to bring it more forward?
I wonder if you couldn't go closer to the front fender and up towards the hood, kinda next to the alternator where the OEM air-box was, but all that heat...... probably cook the spark maker.
Maybe towards the valve cover and up close to the hood? piping would get curvy though.
Hunter Rich
TJ Enthusiast
I had one look like that in an old plymouth Volare. It happened when I was spinning the tires in gravel and suddenly found the pavement.
Brianj5600
TJ Expert