AustinGriggs
Well-Known Member
As a Subaru nerd (I have a few)... I approve of this thread. Nice Duster!
71 Duster 360 turbo build
- Thread starter turbovan
- Start date
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I’ve been sorting out all the new editions and the car is running great…out of boost. The carb is going lean and I’m running out of ideas. Initially it was doing okay running it exactly how it was last year with no PV and 86 jets front, 96 rear. Was still going a little lean(12.5) up top so I decided to try out a front pv to add some fuel. After tossing in a 6.5 pv with no other changes the carb has done nothing but go 14:1+ under boost. The power valve didn’t seem to be opening. Pulled the carb hat off and drove na; pig rich sub 10:1. Pv definitely opening when the hat is off. Put the pv plug back with the same jets as before and still 14:1+. Verified fuel pressure is rising 1:1 with boost, and triple checked float levels. Whatever changed during that power valve install I do not know, but I guess I’ll have to pull apart and clean the entire thing.
Besides that I did some low effort paint so that I would qualify for vastly cheaper antique insurance.
Besides that I did some low effort paint so that I would qualify for vastly cheaper antique insurance.
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Have you tried the vent tube extensions?
https://www.theturboforums.com/threads/vent-tube-extensions-wow.306085/
https://www.theturboforums.com/threads/vent-tube-extensions-wow.306085/
TT5.9mag
Two atmospheres are better than one
If your power valves are not boost referenced they need to be. Also, depending on which Holley you’re using if it has the check ball for power valve backfire protection, boost can actually force the ball closed and seal off the power valve.
Holley 650 double pumper
I am running vent tube extensions
CSU hat
No check valve
I tried a boost referenced power valve yesterday; no change.
Regular power valve was working when I started tuning last year and should still work since I’m at only 8psi.
I am running vent tube extensions
CSU hat
No check valve
I tried a boost referenced power valve yesterday; no change.
Regular power valve was working when I started tuning last year and should still work since I’m at only 8psi.
Yes they have been drilled by myself during initial tuning. I don’t remember the size, but they’re too big so I plan to re-drill and tap for adjustable pvcr’s. That’s why it goes so stupid rich when the carb hat is off.
dusted
Well-Known Member
I’m running a Holley 650dp. No vent tube extensions and the spectre hat. After the hanger18 mod I ended using a 6.5 pwrvalve and up opening the pvr from a 60 to a 90 as well as the icr from a 35 to a 53. I have rear PV blocked. 72 front jets and 78 rear. Cheap 044 Bosch pump with -6 feed, return aeromotive boost reference FPR. I can flood it out to a 10.0afr at 10psi with a 2 sizes bigger jet change in rear. Wondering if you have some trash in one of the circuits. You should be swimming in fuel.
turbodart68
Well-Known Member
I am the one who had the carb we reversed engineered to come up with the “hangar 18 mod” hangar 18 is my buddy. We took my 750 apart and modified his carb exactly the same. I got that carb from Ak Miller and ran a small block blow through set up in the mid 90’s. The PV orifice needs to be opened up and the anti blow back check ball needs to be removed oht of the signal circuit. The carb hat causes lean cylinders even though the O2 sensor says its ok or rich. You need to be at least 10 sizes bigger on the side where the hat points. Also a single plane intake really help with distribution. This is a cool build, i love it when someone has the guts to take on a project like this and is willing to learn. I cant wait to see what it runs at the track. I had a similar set up back in the 90’s. It ran 10.0s at 133 with 2.76 gear off the foot brake with a mostly stock 360.
Disassembled, cleaned and soaked the whole carburetor; no change. I believe the change in hat direction is to blame as the smaller primary jets are no longer sufficient now that they receive more air. PV up front opens if I stab it(sub 10:1 bog), but then closes as soon as boost kicks in. So I’m going to try something different. 1:1 secondary linkage with a 6.5 PV in the rear, and a boost referenced power valve up front. I drilled and tapped the front and rear PVCR’s as well as the HSAB’s. I’m going to square the jets, and go bigger on the front PVCR’s.
My hope is that the regular PV will stay open in the rear since it doesn’t want to work up front. I also hope that it doesn’t starve for fuel without some kind of extension.
My hope is that the regular PV will stay open in the rear since it doesn’t want to work up front. I also hope that it doesn’t starve for fuel without some kind of extension.
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Well a month ago I brought my 8 3/4 center section to a very reputable shop to swap the gears from 3.91’s to 3.23’s. Supplied them with ALL the parts needed, and just picked it up today because they hadn’t even started on it. Covid world.
So tomorrow I’m going to attempt it myself. 489 housing with a crush sleeve eliminator kit from Dr. Diff so if anyone has any advice I’m all ears!
So tomorrow I’m going to attempt it myself. 489 housing with a crush sleeve eliminator kit from Dr. Diff so if anyone has any advice I’m all ears!
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Well the gears worked out great, but my motor was hurt while messing with the carb(no boost). My dipstick was wrong and I hurt something on the bottom end. Oh well the motor served it’s purpose.
Decided it’s time to stop screwing around so my new build is at the machine shop now.
1998 magnum block with a half fill
Hughes main girdle and stud kit
Scat forged 3.58 crank
Eagle H beam rods
DSS -18 cc forged pistons .030 over
Custom hyd roller: 227/231 on 114. 603/560
CNC Speedmaster heads w/ valve job
Modifying my intake for EFI
4bbl throttle body
Custom fuel rails
Still shopping for Injectors (probably 120Lb)
Teetering between a S480 and S475, but I’ve always wanted to run the 80.
Needs a roll bar, and I’m going to start prepping the car for a real paint job. Going with Bikini pearl. I hope to have it together around November. Unfortunately, our last remaining drag strip here in Phoenix just announced that 2023 will be their last season so I have a deadline to meet.
Decided it’s time to stop screwing around so my new build is at the machine shop now.
1998 magnum block with a half fill
Hughes main girdle and stud kit
Scat forged 3.58 crank
Eagle H beam rods
DSS -18 cc forged pistons .030 over
Custom hyd roller: 227/231 on 114. 603/560
CNC Speedmaster heads w/ valve job
Modifying my intake for EFI
4bbl throttle body
Custom fuel rails
Still shopping for Injectors (probably 120Lb)
Teetering between a S480 and S475, but I’ve always wanted to run the 80.
Needs a roll bar, and I’m going to start prepping the car for a real paint job. Going with Bikini pearl. I hope to have it together around November. Unfortunately, our last remaining drag strip here in Phoenix just announced that 2023 will be their last season so I have a deadline to meet.
Intake manifold conversion close to done. Decided on decapped ford 5.4 flex fuel injectors which flow 100lbs at 58psi base. Still need to build the injector harness and find a TPS sensor. I’m going to toss it on the old engine(still in the car) to work out the bugs. At least get it to start and idle. The new motor is still at the machine shop for a line hone, but I’m not exactly in a hurry since I’m still waiting on head studs I ordered back in January.
racerjoe
Well-Known Member
Is that the ebay special 4 barrel throttle body? That's the one I'm using and finding the correct sensors for proved to be a slight challenge since it didn't come with any information. Mine uses a Ford TPS, something from a late 90s explorer. I went to the junk yard and snatched a few and cut the harness to get the connector. The IAC is a from a GM product, late 90s as well. Apparently GM made them with a brass plunger and also a rubber plunger. The brass plunger IAC won't seal the hole. Ask me how I know.... Lastly, I ended up using a TMAP instead of just a MAP. I think they come off modern era cars, but I'm not 100% sure. I bought my from Ballenger Motorsports. They do have 3 bar for boosted applications.
This throttle body is from Speedmaster via eBay, but it’s different from the other eBay pieces like yours. Part number pce138.1001 . Is your tps the blade type? The throttle sensor shaft on mine is a half moon shape, and Speedmaster sells their own sensor for $100 after shipping. I cannot find any info on an OEM sensor that works with it, but I’m going to the auto parts store hoping someone patient can give me a hand. I really don’t want to be stuck looking for an outdated proprietary sensor 10 years down the road. As for IAC I’m not utilizing that at this time. I’m using the micro squirt IAC PWM output to control my fan which is a bit more important at the moment.
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racerjoe
Well-Known Member
That should use the standard GM style TPS. Commonly found on pretty much any LS based engine.
Thanks. The LS tps does seem to fit the shaft okay, but very loosely. It won’t work with the tapped throttle body holes, and throws the pigtail straight up into the hat, but I’m going to try it. Hopefully it will be accurate and save me $80
That intake turned out amazing! What is your source for those “decapped ford 5.4 flex fuel injectors which flow 100lbs” ?
Thank you. Only my 3rd time welding aluminum, and it went okay. The fuel rails were very easy to do with a drill press.
This was where I first read about the injectors. I haven’t found too much other chatter on them.
1000cc decapped injectors - LS1TECH - Camaro and Firebird Forum Discussion
Reading back they’re closer to 90lbs. I paid $180 for a refurbished set.
This was where I first read about the injectors. I haven’t found too much other chatter on them.
1000cc decapped injectors - LS1TECH - Camaro and Firebird Forum Discussion
Reading back they’re closer to 90lbs. I paid $180 for a refurbished set.
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Matts440
Well-Known Member
Maddart used one from a Nissan or Q45 TPS, on his now my throttle body, might see if it can work for yours.
Manifold, injector wiring, and fuel lines are finished. Installed a second fuel pump, and waiting on a fuse block to finish wiring them. Then I can test for leaks and injector function. Once that’s complete I just need to bolt the manifold down and fire it up(I hope!). Oh, also need to figure out a throttle cable solution.
I did need to buy the $100 Speedmaster TPS sensor. The GM sensor just wasn’t going to cut it.
Engine is back from the machine shop. Forgot to have them install cam bearings so I’ll be doing that for the first time(using the rustyratrod’s write up). ARP head bolts are “supposed” to ship this week. If they don’t I’m going to cancel and buy the Speedmaster studs. Not my first choice, but the LS guys have had luck with them.
Decided to stay with the GT45 for the time being. With our last drag strip closing at the end of the year I need to look beyond drag racing, and this turbo will already provide more power than is usable on the street…for now.
I did need to buy the $100 Speedmaster TPS sensor. The GM sensor just wasn’t going to cut it.
Engine is back from the machine shop. Forgot to have them install cam bearings so I’ll be doing that for the first time(using the rustyratrod’s write up). ARP head bolts are “supposed” to ship this week. If they don’t I’m going to cancel and buy the Speedmaster studs. Not my first choice, but the LS guys have had luck with them.
Decided to stay with the GT45 for the time being. With our last drag strip closing at the end of the year I need to look beyond drag racing, and this turbo will already provide more power than is usable on the street…for now.
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