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Discussion Starter #1 (Edited)
ARP The Theme - Ceci N'est Pas Un Citron (This is not a Lemon)
This year's theme was an homage to Rene Magritte (everyone's third favorite surrealist). Why third favorite? Can you name any other surrealist after Dali and Picasso? I can't. I'll post a link to more of the "official" lemons results/pics.

For this theme (and clearly not our driving), we WON a trophy for "Organizer's Choice."

Highlights Included:

* Team dressed up in suits with red ties and green apples in front of their face -- homage to "Son of Man"



* Giant green apple on hood made out of carbon fiber applique (so it looks racecar-y) - LOST during tow to track through the rain

* Giant pipe on top of the tbird's roof -- homage to "The Treachery of Images"


* "Ceci n'est Poulet Entier" [This is a Whole Chicken]. A framed picture of the chicken under a plastic cover (homage to "This is a Piece of Cheese" and our previous racecar themes that involved a chicken wearing a camera - https://www.24hoursoflemons.com/blog/73-hella-sweet-lemons-car-of-the-week-bosozoku-texino-egg-laying-machino

* Museum labels everywhere
* Green apple shifter (not for racing)
* Citron Presse (Lemon juice) label for the
* Porsche Carerra Script under the doors "Ceci N'est Pas un Citron"
* Citroen Badge on the hood. Did you know that Andre Citroen came from a produce company and took his name for the dutch word for Lemon? I didnt.




The Car
With a V8 that actually runs well now (new SS valves), the car is much faster than when we started 7 years(!) ago. The trick suspension also really makes the car handle but probably contributed to some of our racing incidents.

PRE-RACE: I finally figured out the bucking/surging issue we experienced in the pits -- it's the MAF!. Since I live in SF and I cannot take the car around the block, the first laps of every race have pretty much been a shakedown as I cannot test my car before the flag drops. We swapped the MAF to our backup and the issue mostly went away! Time for a new spare MAF (I have already cleaned the old one so it's probably EOL).

Engine: It took my 3.5 attempts to build a proper V8 w/ a matching cooling system and it finally looks like I succeeded. While we finished our last race with the same engine that we started with, we noticed that the engine was producing low vacuum a month before this year's race so I pulled the heads, confirmed that multiple intake valves were leaky, and had SS valves installed. While this was painful to spend this much on GT40 heads worth ~$300, the result was a glorious sounding engine that never went over 240F oil (at pan) and 184F coolant (at the radiator output). The engine sounds glorious which pulls hard from 3K-5.5K RPM and even under full load (which was hard this weekend because of the slippery track), we didn't want any more power. If anything, we could have done with less in a more efficient pkg. I already told my teammate though that there's no way in hell I'm going to go BACK to a V6 after having done this much work.
- Side Note: since we didn't have much to do at the race on Sat night, my teammate and I helped another fellow tbird racer do a quick and dirty HG swap (which in the end didn't help b/c the heads are likely cracked). While there's so much room around the 3.8SC in the tbird engine bay, there's also so much crap on that engine to take on/off that the swap took 3ppl with tbird experience 5+ hours to do. An engine swap might have been quicker but there's still a ton on that engine compared to the 302/5.0. For this application (endurance racing), I'm not sold on a SC.


Suspension: the trick suspension I worked out with MaddMartigan has worked marvelously.
- I checked and as designed, the front bilsteins have held up without any issue and even my booger welds that hold the monoball housing in place in the cup of the top mount stood up to a full day of hard racing. I remain skeptical though that anyone would want this setup on a road car. Sears Point is a relatively smooth track and you can feel every shimmy and surface texture change.
- I should put a G-meter in the car (or run the app on my phone) but you can pull some serious g-forces around the carousel.
- The downside is that that the field we race with has ALSO gotten faster and there's simply no way to remove any more weight from our tbird compared to other more lightweight chassis (3150 ready to race, 3300-3350LB w/ driver, other cars are probably in the 2800LB range).
- We might also not have enough tire for the car now even with 16" rims -- esp in the rain/drizzle. With this stiff a suspension, the car simply isn't as forgiving as previously (you could toss it in the corner, breaking grip on the rear wheels through the whole corner, and catch it at the end). In the 8 races I've personally driven, I've never spun a car in a lemons race and I did it twice in one stint on Sunday morning after the track had been misted all day. This shook me up enough to pit and have another driver relieve me.
- Also, Apparently, if you put enough crap on your car, noone will bounce on the hood, either.

Comm System: Our latest comm system uses a 2G cellular modem on an Arduino to send text messages. Without any wires on the driver it made driver swaps a breeze (no testing necessary as the system sends a "888 TBIRD - Ready to Rock" SMS message upon boot-up) and all of the drivers can walk around w/ their phones and just rush back when they get a message from the car.
- What i did learn was that just because you have a fast and furious style push button on your steering wheel doesn't mean you want the messages to go to that button.
- For several times during the race, we'd rush back and watch to see if the driver was pitting because
- We also learned to NOT turn on the "return to pit" light on the steering column unless WE the pit crew wanted him to return. If the driver fat fingers it and we turn the light on, the driver could be pitting unnecessarily because he thought WE wanted him to pit.
- SOLUTION: Have TWO switches so the driver can send one of two messages: "Returning to Pits for New Driver/Fuel" or "Returning to Pits - Repairs needed". Also, move the damn button.
- This will tell us whether to have the pitcrew dressed in a racing suit (for refueling or to hop in the car) or a repair suit (to fix something).

Incidents/Lessons Learned
* Get a new spare MAF.

* Had a fuel leak from the TOP of the tank after messing with the fuel pickups: We pulled my design of upgraded fuel pickups because it was interfering with the fuel level reading and we NEED that. Solution: the temp fix was to use some gasket maker on the old gasket but Will definitely buy some spare gaskets for a future race OR upgrade to a fuel cell (which is a ton more work to enclose or a $1200 FIA cell). Either way, this is probably the thing we will spend the most money on before the next race (if we decide to do so). The challenge is that even with a larger fuel cell (22gal), most of our drivers (myself included) don't have the endurance yet to do 2-3hr stints.

* We had the fire extinguisher blow up while one of the drivers was out on the track. HE thought he had broken the car and we had the car jacked up and the front wheel off before we realized that the reason the inside of the car looked like the aftermath of a columbian cartel's drug party was because the extinguisher was rolling around behind the driver.
Solution:Mount the Extinguisher in the car better (and duct tape the latch down) and DO NOT TOUCH the extinguisher when refueling (use another extinguisher).



* Another driver lost the back right wheel on the track. I'll get the video clip of him being passed by his wheel soon but luckily, he was already at the edge of the track so he was able to coast into the muddy side. It took more time to get towed back to the pits than it did to swap the axle and get the car back to doing laps again (20min repair and <1hr track time lost)
Upgrade all of the wheel studs: this was the first race where I was starting to feel serious G forces around the carousel at Sears Point -- not quite gokart level G forces but definitely more than before. Studs which were made by domestic american metallurgy 15+ years ago and have since seen 100K+ miles were NEVER meant to take this kind of abuse. They just sheared off.
Solution: find the right ARP wheel studs for the tbird. I'll probably discuss this later in this thread but the plan is to upgrade all studs on the car. This is a must do upgrade.




* EGR bung: I forgot this one; on day 2 we blew out the EGR bung cap that I had fabricated. Luckily I could just pull the plug from the spare engine and just tack/booger welded it on. I need to find out the threading so I can buy some spares (for the spare engine and for the main engine).

* Become better drivers: with all the suspension mods, this car is much less forgiving than when we started. With our old V6, we could literally toss the car in the corner breaking traction on all four wheels and have the confidence that we could catch it on the other side. Now though, we make so much power vs. our traction that we can literally break traction in a corner if we give it too much throttle in 3rd around a corner. Quite frankly, when the road was damp I was scared of using this car's full potential. After 8 lemons races (I did one with a friend's team) and several track days I probably have 24-30hrs of on track time. Until this weekend, I had never spun the car in a race (and my friends 3rd gen supra once during a practice session). This weekend I spun our tbird TWICE in one stint -- this shook me up enough that I immediately pitted and had a friend relieve me as a driver with the recommendation that he be very, very cautious until the sun came out and dried things up more.

I can say with confidence now that I've built-up a better car and maintenance/crew than we have drivers. I also need to work out a new, even more ridiculous theme.




Yes, I'm still the guy in the center, yes, my name is really Gunn, and yes, my eyes get even more squinty when I'm happy.
Thanks again for everyone here who has given me useful suggestions/advice/help.
-g
 

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Sounds like you are having fun with the 'Bird.

I still want to see dash cam video of some racing.
 

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I'm glad the suspension mods are working out. I've taken mine out a few times with the changes I've made and I've described the ride to my coworkers as "a shopping cart with a very thin pillow being pushed across a gravel parking lot".

Man, it feels like it's on rails otherwise. I'm running 275's on all four corners and they have a treadwear rating of 200 so I'm hoping I won't have the same grip issues that you've had.
 

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Discussion Starter #4
I'm glad the suspension mods are working out. I've taken mine out a few times with the changes I've made and I've described the ride to my coworkers as "a shopping cart with a very thin pillow being pushed across a gravel parking lot".

Man, it feels like it's on rails otherwise. I'm running 275's on all four corners and they have a treadwear rating of 200 so I'm hoping I won't have the same grip issues that you've had.
It's jarring enough that i'm actually a little worried about the rest of the car. Even with a full cage to help hold things together, checking for stress cracks along the shock towers and firewall is on my TODO list :)

You can feel every single imperfection now. On day 2, I was noticing a little shimmy and when I came in, we found that tightening the lug nuts to only 85ft-b vs 100ft-lb wasn't enough (they had worked themselves a little looser). Losing a wheel once a weekend was bad enough; TWICE would have been too embarassing.

I'm also not sure if the front braces are really do anything; my friend thinks that turn in feels more immediate now but considering how many other changes we made, I'm not sold that this was more than dead weight + something for me to build b/c I had the scrap metal laying around. At least I know now that I have everything tucked up high enough even if the car goes on an offroad excursion.
 

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Awesome, man!

Your buddy looks wild in the suit. :)

Looks like a Lot of fun.

I'm happy to help any way I can; anytime. :)

As far as themes go, I'd say Dali is pretty common in Lemons, with all the bent metal... :grin2:
 

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It's jarring enough that i'm actually a little worried about the rest of the car. Even with a full cage to help hold things together, checking for stress cracks along the shock towers and firewall is on my TODO list :)

You can feel every single imperfection now. On day 2, I was noticing a little shimmy and when I came in, we found that tightening the lug nuts to only 85ft-b vs 100ft-lb wasn't enough (they had worked themselves a little looser). Losing a wheel once a weekend was bad enough; TWICE would have been too embarassing.

I'm also not sure if the front braces are really do anything; my friend thinks that turn in feels more immediate now but considering how many other changes we made, I'm not sold that this was more than dead weight + something for me to build b/c I had the scrap metal laying around. At least I know now that I have everything tucked up high enough even if the car goes on an offroad excursion.
Good point on the lugs. I need to tighten mine before this Saturday then. My biggest fear is that something is going to break because I've not driven a car this stiff before.

BTW, I absolutely hate power steering and all of the problems that it brings with it. I really need to figure out a way to get rid of it.
 

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Discussion Starter #7
Good point on the lugs. I need to tighten mine before this Saturday then. My biggest fear is that something is going to break because I've not driven a car this stiff before.

BTW, I absolutely hate power steering and all of the problems that it brings with it. I really need to figure out a way to get rid of it.
I'm not so sure that a PS delete is a good idea. As heavy as our car is right now, your car is more so because of all the interior/glass stuff still on the car.
I ALMOST was able to catch the car and keep it pointed in the right direction when I overcooked it in the carousel (long downhill sweeper left -- you can see it in this video -
).

I think 4 or 5 cars were totalled here this weekend and it was pure dumb luck that i lost it when there was no traffic behind me. In the case of this duster, he lost it and totalled out this poor SE-R that was following behind him.

I was in the middle of the track at the end of the carousel, the back end starting sliding out, I counter steered and caught it and the car started sliding out the other way (slick morning conditions). I caught it again but this time overcorrected and the car just spun around. I then had a pucker moment as I had to restart the car while staring down at traffic which (thankfully had time to see me and drive around me while I carefully got my car pointed in the right direction and moving).

I would agree that this car's steering is maybe "overly" powered for track work but as heavy as this car is, I don't think i would have been able to catch it the second time without power steering.
-g
 

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What size tires are you running, stock 225/60/16? If it were me, I'd go up to 245 or 255 width tires all the way around.
Not sure how much you care about speedometer accuracy, but you can go with a 255/50/16 and have a nice big contact patch and as long as your suspension is somewhat close to stock positioning in the wheel well, clearance won't be an issue.
 

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I've always wanted to figure out how to put a knob on my assist, and turn it down manually.

It's designed with a computer to monitor your input, and if the rate of change of steering speed changes suddenly, or any one of several triggers, including braking, it goes full assist; I think that's pretty asinine myself, but I guess it cuts down on lawsuits.

Manual adjustment seems better than the alternative.

HMMM: Racecars...
Are you guys still running the EVO box and all?

If not, do you still have the box, and is the EVO-type pump still mounted on the car?
 

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I've always wanted to figure out how to put a knob on my assist, and turn it down manually.

It's designed with a computer to monitor your input, and if the rate of change of steering speed changes suddenly, or any one of several triggers, including braking, it goes full assist; I think that's pretty asinine myself, but I guess it cuts down on lawsuits.

Manual adjustment seems better than the alternative.

HMMM: Racecars...
Are you guys still running the EVO box and all?

If not, do you still have the box, and is the EVO-type pump still mounted on the car?
I still have it on my car. My understanding is that the EVO actually dials down the power steering under speed. I'm interested in losing it because I still have problems with the pump staying reliable.
 

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Discussion Starter #11
I still have it on my car. My understanding is that the EVO actually dials down the power steering under speed. I'm interested in losing it because I still have problems with the pump staying reliable.

Hrm.
I have my EVO solenoid in my PS reservoir is unplugged since all of that stuff (computer, sensor, etc) is pulled off my car. Since this places the PS system into "full assist" at all times, I wonder if the EVTM will give guidance on how to place it in minimum assist at all times. One more item on the TODO list.
-g
 

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Discussion Starter #12
What size tires are you running, stock 225/60/16? If it were me, I'd go up to 245 or 255 width tires all the way around.
Not sure how much you care about speedometer accuracy, but you can go with a 255/50/16 and have a nice big contact patch and as long as your suspension is somewhat close to stock positioning in the wheel well, clearance won't be an issue.
Current tires are Dunlop Direzza ZII Star Specs in 225/45-R16 or BFG Rivals in 225/50-R16
The BFGs have approx 0.45" taller sidewall. Going with BFG Rivals for Race #5 (the one where we couldn't solve the alternator charging issue and the cooling issue so we tucked our tail between our legs and went home) was probably a mistake. Going with them for our last race (Race 7) was simply an economics decision (I could have either bought another set of the star specs or used the BFG Rivals which had only 17 laps on them and were 2 years old. I opted to use the old tires and will sell them off before our next race so we will have both new star specs and old star specs of the same size).

Our car is lowered but not excessively so; there is still a decent amount of clearance even with the smaller diameter tires.

We don't care if our speedometer is off and while I used to care that the speedometer would show a consistent number, I don't really pay attention to it anymore. In our first race, I seem to recall testing and going with the spec miata 205/50-R15s over stock actually improved our 1/4 mile times (from IIRC 17.95sec down to 17sec) because the smaller diameter tired effectively increased our final drive ratio. I remember I found this to be hilarious.
 

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Current tires are Dunlop Direzza ZII Star Specs in 225/45-R16 or BFG Rivals in 225/50-R16...
What are the rules on tires for the event? In the sizes that you list, there are some pretty good tires that would work on the track much better than those. With the suspension changes you've made, I would imagine that tires that aren't all that sticky are going to be a big problem.
 

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Discussion Starter #14 (Edited)
What are the rules on tires for the event? In the sizes that you list, there are some pretty good tires that would work on the track much better than those. With the suspension changes you've made, I would imagine that tires that aren't all that sticky are going to be a big problem.
190 TW minimum. Plenty more cars (including other heavy ones) have proven that Direzza ZIIs have consistently good treadwear and will last at least one full race. The other popular choices are Falken Azenis RT615K and BFG Rivals.

There are some new tires that are made to "game" these spec rules (they were formerly 120TW tires IIRC but now ship with deeper treads and are rated at 190TW b/c TW is not an "abosolute" unit of measurement but one that is relative for each mfg) = Toyo Proxes R1R
Those simply won't last a lemons race (too soft) esp with a heavy car. Going harder (ex: Toyo Proxes R4 will overheat and will start chunking -- I know this from personal experience.

I found that the BFG rivals tend to get harder over the course of the race where the Star Specs start feeling "greasier". I'll probably go with more star specs.

Q: is it possible to find a WIDER rim than the stock 16" we have in the tbird bolt pattern but in the proper offset? IIRC, these stock SC rims are 7" wide. THAT would get me more contact patch without unduly stretching these tire, right? I could go that route and maintain the same tire on both the main and backup wheel sets. The alternative would be a 17" in the tbird bolt pattern but that means we will be spending more per tire set (not as ideal since we but a new set for most races, do another track day, and sell the tires off). My last choice would be a hub swap since I would need to swap hubs on all 8 of my spindles/axles (front/rear/spares) and that MUST offset the value of cheaper 17" mustang wheels

I found some pics here but I'm not looking for a cosmetic decision.
https://tyrestretch.com/8.0-225-45-R16/
 

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For what it is worth, I ran the Direzza's, the Azenis, and the Nitto NT05, and the NT05 was not only the cheapest of the bunch by quite a large margin, but was also stickier and more consistent throughout the race than the Direzza's or the Azenis. The problem for you is they don't make the NT05 in a 16" size, so you would need to step up to 17s. If you feel you need more tire (which I think you do), a Mustang hub swap should be in your plans. The Mustang Bullet wheels are 17x8.5, and at least around here are on craigslist for under $200/set all day long. That will allow you to run a 275/40/17 at all 4 corners. Since you were looking at replacing the wheel studs anyway, now would be the time to do this swap. The front hubs will come with studs already in them (although they will be the Mustang thread) and the rear hubs you can re-drill and put matching Mustang studs in so you have the same thread all the way around. I have a tool that bolts to the hub and will allow you to re-drill the rear hubs without even removing them off the vehicle, which I can loan you if you want. For the front rotors, doing this swap will allow you to use a stock 99-04 Mustang rotor, and for the rear rotors, use tbird rotors and either elongate the holes outwards with a file, or re-drill them when you re-drill the hub. I don't remember what front brakes you are running, but the 17" wheels will also let you upgrade to the 13" Cobra brakes, which was a huge improvement. On our car, after going to the 17s with the NT05s, and the 13" brakes, after seeing it on the track for a day, judge Phil described our car as a menace!
 

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Current tires are Dunlop Direzza ZII Star Specs in 225/45-R16 or BFG Rivals in 225/50-R16
The BFGs have approx 0.45" taller sidewall. Going with BFG Rivals for Race #5 (the one where we couldn't solve the alternator charging issue and the cooling issue so we tucked our tail between our legs and went home) was probably a mistake. Going with them for our last race (Race 7) was simply an economics decision (I could have either bought another set of the star specs or used the BFG Rivals which had only 17 laps on them and were 2 years old. I opted to use the old tires and will sell them off before our next race so we will have both new star specs and old star specs of the same size).

Our car is lowered but not excessively so; there is still a decent amount of clearance even with the smaller diameter tires.

We don't care if our speedometer is off and while I used to care that the speedometer would show a consistent number, I don't really pay attention to it anymore. In our first race, I seem to recall testing and going with the spec miata 205/50-R15s over stock actually improved our 1/4 mile times (from IIRC 17.95sec down to 17sec) because the smaller diameter tired effectively increased our final drive ratio. I remember I found this to be hilarious.
Because you're on a race track, I think those narrow as hell 225's are killing you. Both are very short, which is fine and all, but the Lemons races aren't about top speed/acceleration but more endurance, right? If you were to use a 255/50/16, they're 26.1" tall vs 23.9" and 24.9", but you gain a full inch of section width. You could probably find something more track oriented in a 245 series as well, which is still 9.6" of contact patch vs 8.9" Between the four corners, you have almost 3" of additional rubber on the road with a 245 series tire. I know the 255/50 are few and far between for tires, BFG makes a sport comp in that size, but they're pricey, so maybe look in the 245 range. Tire Rack has lots of track rated tires in 245/45/16, which is very close in size to your listed tires, smack in the middle at 24.6" tall, and with a more desirable 9.6" contact patch.

If you want 255/50/16, there are 5 choices available on Tire Rack for track day competition, even one rated for rain days. Not sure if you need a track tire or a good performance street tire.

Since your car is skittish with the narrow tires, I'd say wider is better, and at all four corners. Having a taller tire will give you more sidewall too, which may help cushion some of the bumps. A 24.6" tire gets you 4.3" of total sidewall, where a 26.1" tire gets you about 5" of sidewall.

Edit... I read your following posts and see that you need a higher tread tire. I see that most of the crowd is running tires that just don't come any wider than a 225 section width. Do you have any guys running wider tires showing good luck with particular brands?
 

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I don't have time to read through all the details and comments right now but I did catch the highlights of your awesome write up.

You guys ROCK! That's the coolest Tbird story I've read in a long, long time.

Congratulations Gunn!
 

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Discussion Starter #18
Edit... I read your following posts and see that you need a higher tread tire. I see that most of the crowd is running tires that just don't come any wider than a 225 section width. Do you have any guys running wider tires showing good luck with particular brands?
I need to start running numbers on different scenarios and will take your comments about the 245/45 tires under consideration.

As far as running wider tires are concerned, wider isn't necessarily better in lemons. I seem to recall some issues with some e30 teams experimenting with wider tires.
Ahh, here's the thread I recall.
http://forums.24hoursoflemons.com/viewtopic.php?id=34150

In it, you will find that by going wider, one team tore their stock steering box off the chassis because the e30 was simply not designed to support the extra force of added meats. Others have found that they have to swap out wheel bearings (which we've NEVER done BTW).

While some cynics might say that we just forgot to torque down our RR tire, I know I checked the torque on all the lugnuts that morning before sending the car on the track. Personally, I'm willing to bet from my Butt in Seat (BIS) dyno that we are pulling a good deal more Gs with our new suspension setup than before and this lateral stress is what sheared those lug nuts off. I lost the wheel off a donor car I was flat towing from a guy in northern CA. When the lug nuts came off that wheel, a few of the wheel studs had broken off but a few more were bent. Looking at the axle that we took off the tbird after losing a wheel at this race, all give wheel studs were broken off with <1cm of nub sticking out of the hub. TO me, that points the finger more towards metal fatigue than dumbassery.

-g




Tires poking past fender (Page 1) ? LeMons Tech ? The 24 Hours of LeMons Forums
 

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I still have it on my car. My understanding is that the EVO actually dials down the power steering under speed. I'm interested in losing it because I still have problems with the pump staying reliable.
The EVO is a solenoid that bypasses a fluid circuit; I've had it apart a bunch.

It does default to full assist; If I come up with a driver circuit, I may try to make it manually adjust.

Has anyone got a box they aren't using?

The EVTM lists the inputs; I'd like to see what the circuitry looks like. :)

A hi-res picture of the inside might be enough; I need both sides.

Edit: I'll be Damned! After googling, This same setup is used on GM cars of the same era, lol.
Sensors and all.

I never thought to search GM forums; I'm pretty sure this is a 'Saginaw' type pump...

Check this post out:

These Saginaw pumps have been around forever, and there is a way to easily adjust the boost they provide. Did A LOT of research online into this, and it has to do with the flow control valve inside the pump. This is NOT to be confused with the flow control FITTING which is what threads into the back of the pump in place of the EVO solenoid assembly when retrofitting back to the pre-97 style of steering assist. Behind that fitting is a spring, and behind that spring is the flow control valve. This valve has a hex nut on the end which is epoxed into place on later style units (my 96 was epoxied, so anything we'r working on here will most likely be as well). Way back in the day, they were not epoxied into place. The amount this hex nut is tightend down onto the fitting controls the pump's output and thus the amount of steering assist. GM sets the clearance on these at .024" on these trucks. They set the hex nut and the epoxy holds it in place. It used to be that they used shims under the fitting to set this clearance, but in modern times they just tighten down the nut to the set clearance and let the epoxy hold it there. This hex nut applies a pre-load to a spring-loaded check valve assembly inside the flow control valve, so how tight or loose this hex nut is will determine that preload pressure... this is quantified by the clearance from the base of the nut to the end of the flow control housing.

Without a power steering pressure gauge, it is somewhat a matter of guesswork to determine what the clearance needs to be reset to in order to provide the desired boost level. If you want MORE boost, then tighten down the hex nut (less clearance), but since we are wanting LESS boost, we need to be shimming the hex nut out. One could conceivably remove the hex nut (difficult because of the epoxy but do-able without damaging the spools on the valve), put some threadlock on it, and tighten back down to the desired clearance using a flat feeler gauge (go, no-go) to check the clearance, somewhat like checking spark plug gap.

Based off some readings I found in a magazine article online, with the stock .024" clearance, the pump is putting out about 1,400 psi. Moving up to .077" clearance yields an output of about 800-850 psi, for a difference of 600 psi. The difference in the shim (.077" - .024") comes out to be .053", so given that figure I concluded that a ballpark figure would be about 11.3 psi reduction in pressure for every .001" of clearance. Again, these pressure readings are theoretical, as I have not read actual pressures off of one of these trucks with a gauge myself, but I'm using the above info as a baseline for my own experiments.

I was planning to use shims instead of the threadlock/epoxy method to set the valve, so I located a hot rod shop out in California which sells kits to re-shim these Saginaw boxes and even comes with a special jig you put the flow control valve into which helps keep you from damaging it while disassembling it. The kit was arund $20, and it included the shims and the jig. I was planning to take the valve apart and put in enough shims to bring the clearance out to .048"-.050", or approximately double the factory setting, which should bring pressure down about 270 psi according to the calculations in the previous paragraph. I have not done this yet though, so I was going to test all this out before posting here so that I could speak more authoritatively about the procedure.​
Isn't this a Saginaw pump with the reservoir built in?



This says the kit is $18 for the adjuster; I'm going to the garage to go look for a pump. :grin2:
 
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