Jeep Strokers

So about 5 years ago i started my stroker build (No, i dont have a build thread yet. Yes, Im a slacker) and about 6 months ago i finished the build. Ive driven the Jeep, a '97 Tj on 1 tons and 40" TSLs, everywhere, however, it has lacked some middle/upper end power. Most of this stems from a series of dumb mistakes i make while building the motor. One thing i desperately wanted to fix, though, was find a way to feed it more cool air. First thing i was route a 2.5" tube into the cowl area where i placed an airfilter.This took my air temps from roughly 170* right behind the rad to a few above ambient.

Next, I really want a larger TB but im cheap so i wasnt coming off the $500 for one. Went to the local P&P and gots me another WJ manifold and Durango 63mm TB. Im a machinist by trade so the next few steps where easy. I ported the manifold:

The next step was to adapt the Durango unit to the WJ manifold. I had a few ideas but this one seemed best. I made an adapter plate and milled a pocket in the mani to be welded up.




The idea was to have the centerline of the old throttle blade in the same location as the new one so i could reuse the throttle cable. Long story short: I trashed a bunch of stock TBs to "make" a new TB shaft/pulley and was NOT happy with the results. Back to square one..... One day Ill revisit this idea but for now its under the work bench. I got to looking at an aftermarket TB and realized it looked a heck of a lot like the stocker. A hand full of measurements confirmed that the stocker can be bored out to 6x.xx". The biggest problem was id need a new throttle blade. But hey, How hard could that be!?
First, i started again with a stock OBDII TB, disassembled it, and flung it in a lathe.
Exhibit A:

Truth be told, i think this could be taken to just under 65mm but its cast aluminium, made by the lowest bidder, so i wasnt taking the chance. The intake tube clamp area gets Uber thin(~.07" IIRC), so 2.500" sounded nice and round to me!
A pic post-turning in my favorite lathe with the stock blade in it:


Ill post up some more pics and info tomorrow. Lemme know what you guys think so far, better yet i love some ideas on the durango TB.

Great work. Way to think 'out side the box".

i went a similar route, had a machinist at work bore my obd 1 TB. he did it in a drill press kinda cutting machine (sorry, im not a machinist) only thing now is that i need to find a throttle plate to replace the one that obviously doesnt fit anymore

So the next big dilemma with the throttle Body is the throttle blade, when closed, it sits at ~10* angle inside the bore. This angle is critical for about 100 reasons but the top two that come to mind are TPS voltage and the shaft arm. My universal scan tool doesn't read voltage for whatever reason but it does read percentage, so whatever, a number is a number. The stocker registered "14.7%" at idle. The shaft arm needed to end up at the same angle so the setscrew/stop would function properly. Sure theres adjustment but not much. Ok, enough of the reasons, how do you plug a round hole at an angle? With an oval! I don't have any pics of the fixture i made to make the blades but ill describe it as best as possible. Its a 3x3x1 block with an angle (10*) cut in it. Horizontally, in the center of that angle i drilled and tapped to 8-32 holes. These were so i could bolt a 3x3 sheet to the fixture for milling. The sheets then went in a mill to have the holes/countersinks placed in them. I need to get a pic of them as well. Anyhow, with the plate at an angle, i milled a 2.500" circle vertically around the center. Viola! The TB shaft had to be heavily modified, which you can kinda see, but the long and short is, I cut the top of the slot off and widened "seating" area. Locktight is a must here! On the the pics:
Assembled on a spare shaft:

Old inside of new:


All in all the new blade seated well but did require some finish filing to be perfect. With the TB finish assembled, I hooked up my scan tool and plugged in only the TPS to the new body. I wanted to confirm that the closed reading was right/acceptable. NOTE: 15.1% is REAL close to 14.7% but not the same. I fired up the motor too confirm idle as seen in the pic below but the sensor reading was off just the tiniest C-hair.


For those of you that don't know how the TPS(Throttle Postion) and Idle air circuit operates; when the blade is closed(confirmed by the sensor reading) the Idle air motor opens and closes to control idle. When you come off idle, even the slightest, the TPS registers the blade is open, the computer will fully open the IAC(Idle Air Control). The computer confirms the airflow increase using the MAP(Manifold Absolute Pressure). If it cannot confirm whats going on, it will surge. Well, 15.1% is enough to cause surge. I loosened the TPS screws to see if i could wiggle it enough be happy but, nope, it wasn't having that. Now what!? I have about 30 TPS's (throttle body hoarding is a thing i have/do; dont hate!) so i modified one by pushing/spinning out the sleeves using a vise and ~.200" drill. The idea was to use a large enough drill, not to cut the sleeves but get them stuck on the drill so i could spin them out. As seen below:

This is what was needed. I got the TPS reading to 14.7% and tightened down the screws using serrated washers to keep everything stationary. I started the jeep, as seen below, and let it idle through quite a few heat cycles just to be sure it knew how how to idle. I blipped the throttle as well to confirm its ability to come back down, a few times.
Finished product idling:


Said TJ:


I tune my jeep using a DTEC controller, made by TurboXS. It modifies the MAP sensor reading according to a scale written using a GameBoyDS. I use an Innovate Motorsport Wideband to confirm my adjustments. Some info on my motor: 4.7ltr using .060" KB944's, Blueprinted and balanced, shotpeened/sanded/polished 4.0 rods, .005 deck, polished combustion chamber, TurboToms old 0331 head w/ LS1 2.02/1.57 SS valves and a svelte Port job, 24lbs injectors, 30ab cam adv 4*, ported WJ manifold, stock Tj header/2.5" exhaust. Ok, so the motor has been real torque pig up to 3K taking a huge crap thereafter. I believe this is partly the TB and mostly my decision to advance the cam . Hind sight is always 20/20. With this new TB airflow increased a good bit from off-idle to 4k warranting a 5% increase(disclaimer: according to my DTEC) in fuel from 0-3k and a 7-9% increase from 3-4K. It still craps the bed past 4K . BTW, i aim for 12:1 with NA motors and 10.5-11.5 with forced induction. Im still not 100% happy with the end result as id like it to pull harder past 4K but i think i have a few hurdles in the way i'll cover later.
My goal with this project (and thread) was to fix an airflow issue (which it did, kinda), log it somewhere so others/I could review it, hopefully inspire others to do this mod on there own. I will hopefully get all my pics together from my motor build and start a build thread soon. Id like to, also, document the changes that come from cam timing adjustments. Im also looking for input from those who know the 30ab cam first hand. Where did you set yours? Why? How do you like it?

I've got plans to make my own 62mm TB from a few spares I have on hand. I wsa going to use the same method to mill an angled mounting base to support the base as well. What method did you use to get the circular cut made though? I'm planning on mounting the support block in a rotary table and find the end mill edge distance from center then just turn it 360 degrees to make the cut. Is that how you did it?

Dodge Dakota TB on mine... kind of a bad pic, but basically the Dakota shaft was used and a proper throttle end was retrofitted onto the Dakota Shaft so that the TV and Throttle Cables can attach to it properly. The only current thing that bugs me but doesnt seem to cause a problem is the angle of the TV cable from the mount to the TB connection... but it never has been an issue. (Might fix this someday)

I can get better pictures if requested.

http://www.jeepstrokers.com/forum/viewt ... 198#p22198

im trying to figure out why you had to cut the throttle plate rod like that. the widening of the slot makes sense, but why cut the "top" section out? what thickness of material did you end up with?

GoMopar440 wrote:I've got plans to make my own 62mm TB from a few spares I have on hand. I wsa going to use the same method to mill an angled mounting base to support the base as well. What method did you use to get the circular cut made though? I'm planning on mounting the support block in a rotary table and find the end mill edge distance from center then just turn it 360 degrees to make the cut. Is that how you did it?

With the plate at 10* angle to the table i placed it in a CNC mill and "cut" a circle. Worked 10 times better than i thought it would have. My other option was to put it on a bridgport with boring head and work my way in from the outside of the plate.

Muad'Dib wrote:Dodge Dakota TB on mine... kind of a bad pic, but basically the Dakota shaft was used and a proper throttle end was retrofitted onto the Dakota Shaft so that the TV and Throttle Cables can attach to it properly. The only current thing that bugs me but doesnt seem to cause a problem is the angle of the TV cable from the mount to the TB connection... but it never has been an issue. (Might fix this someday)

I can get better pictures if requested.

http://www.jeepstrokers.com/forum/viewt ... 198#p22198

Thanks for the pic. Always wanted to see how other did it Thats what i started with on mine but i had to modify less to the existing things under the hood to run the stocker bored out. Thats the ONLY reason the 65mm durango isnt on there.

amcinstaller wrote:im trying to figure out why you had to cut the throttle plate rod like that. the widening of the slot makes sense, but why cut the "top" section out? what thickness of material did you end up with?

I didnt have a hacksaw blade or file thin enough on hand to fit in the slot and widen it so off it came! Besides it was just taking up room in the path of that valuable airflow.

Muad'Dib wrote:Dodge Dakota TB on mine... kind of a bad pic, but basically the Dakota shaft was used and a proper throttle end was retrofitted onto the Dakota Shaft so that the TV and Throttle Cables can attach to it properly.

After looking at yours 20 more times it looks like you kept the stock dakota arm and placed a stock arm to that so you could retain the dakota return spring. Right or wrong? More pics prease?!?

Biggrnjeep97 wrote:

Muad'Dib wrote:Dodge Dakota TB on mine... kind of a bad pic, but basically the Dakota shaft was used and a proper throttle end was retrofitted onto the Dakota Shaft so that the TV and Throttle Cables can attach to it properly.

After looking at yours 20 more times it looks like you kept the stock dakota arm and placed a stock arm to that so you could retain the dakota return spring. Right or wrong? More pics prease?!?

Right... made it simple.

More pics today when i go out to replace heater core.