[HWYSTR455]

New tank came in, dropped the old one, cleaned it up a little, and is now listed in sale section:

https://forums.maxperformanceinc.com...d.php?t=875172


The tank will work fine using the GPA-4 and GPA-5 pumps, up to about 700hp, but is not recommended for anything larger than the GPA-5.


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[HWYSTR455]

UPDATE:

New tank isn't working for me using the GPA-8, the sump is too small, as well as the 2 feed lines to the sump, it runs the sump dry at WOT in like 3 sec and drops PSI to almost zero.

That tank too will be available soon in sale section, it's the 1" deeper one with notched corners, TM34IN-T:

https://www.tanksinc.com/index.cfm/p...rod/prd586.htm

Bit the bullet and ordered a Rick's tank, should have it in a week or two.

Uhg.

EDIT: It will work with the GPA-4 & GPA-5 pumps.


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[HWYSTR455]

Finally got around to installing my Cold Case radiator, and found my new fans for it too. (Still not totally unpacked from move). Need some fittings and a couple other small items to finish it off.

Selling the eBay 4 core radiator and the fans, if any are interested, it's in the for sale section for a while before I list on eBay:

https://forums.maxperformanceinc.com...17#post6531017

Always offer stuff here first before listing on eBay....



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[HWYSTR455]

Rick's tank came in, am almost done with the install. I also rewired the pump circuit to include 10ga wires, and a relays for each.

I did the wiring upgrade before the tank came in, and, low and behold, discovered a failing relay. Since I had added a relay for the new tank/pump assembly, I figured I would add a 2nd relay so if I wanted I could add a 2nd pump as a backup if the primary pump failed.

In the process of completion, I must have swapped the relays around for the primary & secondary pump, and the falling flat at WOT was completely gone. Uhg. Appears to only occur after some time running, and during a WOT pass of more than 3-4 seconds. I guess the relay was clipping out under load or something, but glad I found out!

Still going to put the Rick's tank in though, can't send it back anyway.

The wiring I did uses an 8ga feed wire that splits into 2 10ga wires to power the relays, and has a 60a maxifuse (on the 8ga). The pump hat harness that comes with the pump hat uses 10ga wires, which go to the relays. I'm using the 70a relays that have the larger tabs on them.

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[HWYSTR455]

New tank in, runs great. Now on to some tune refinement.

Had a chance to take a ride through the mountains, had a blast!


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[bulletpruf]

Originally Posted by HWYSTR455

New tank in, runs great. Now on to some tune refinement.

Had a chance to take a ride through the mountains, had a blast!

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Outstanding! Car looks great!

[HWYSTR455]

Thanks!

On the way back I heard a 'clunk' in my rear inner fender well, sure enough, looked when I got home, and it pitched the stick-on wheel weights on passenger rear.

I can feel a vibration around 75-80mph +. Sux. I will pull the wheel after the holidays and get it balanced. Just a bummer is all.

The new tank fill neck has a modern surge baffle, which I appreciate. No more gushing out when the tank reaches full. That ticked me off when it gushed, because I would have to polish the exhaust tips, gas would dry on them.

I wish the tank had a little more capacity, it's like 23gal, 26 or more would be sweet.


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[HWYSTR455]

UPDATE:

So have finally gotten to a point where I can dial in the suspension, knew the springs I had were too weak, since I have considerable wait added to the frontend from the endura bumper, twin coolers, serp belt setup, and the intake setup.

Called up GW to get springs, and they sent me a set, and the thing was worse than the springs I had on it before. Called them, told them the car was sitting on the bump stops, and the guy (not Doug) told me it has to be something else, and asked me what kind of shocks I had. Um. Shocks don't hold the car up.

So they sent me another set. Just as bad. Called them back and told them that the springs that were on it before I started the resto were a little soft to begin with, and asked what those were (rate), and was told they were 680 lbs. Ok, then I need like a 750, or maybe even an 850, and was told it would be too much and they don't have any. AND, because I installed the sets I can't return them. (They used to accept them in the past).

Anyway, in a search for someone that could make springs to my specs, I found Coil Spring Specialties, and placed a build order for some 850 springs, 14" free height. That was calculated by using the previous springs as a baseline, and accounting for added weight on the front end. Those springs should be ready in about another 2-3 weeks.

In the interim, I ordered some off the shelf Afco springs that are 850, but are only 9.5" tall, which would require a spacer, which I also got, and adjustable one. I dialed the adjustment in order to achieve the desired 14" free height, but due to the shorter spring, rose the car too high, so dialed it to 13", which put the front end right where I wanted it, 1.5-2" lower than the rear.

I made several adjustments to the shock settings trying diff combos, and it's pretty close. I will have to try it with the new springs when they come in, since the spring is taller, and will respond diff than a short spring with a spacer. And no, it doesn't ride like a truck. It's stiff, but still does absorb bumps and tracks well.

So, I am pretty close to the desired setup, may drop back to a 750 lbs spring that's 15" or 16" free height, will just have to figure that out once I get the 850s.

As an example, the 560 lbs spring that I just removed, made the car rest on the lower control arm bumpers. The 680 lbs springs that were in it as it lived as a LeMans were the 680 lbs, and those would bottom and bounce off the lower control arm bumpers on dips and stuff. So I know I'm close with the 850s. Might need an 800 lbs spring, but will try a taller 750 lbs spring beforehand.

Also, as soon as I can, I will take the car to get it's corner weights on some race scales, so I know what I'm dealing with.

Questions/comments/suggestions are appreciated.



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[bulletpruf]

Originally Posted by HWYSTR455

UPDATE:

So have finally gotten to a point where I can dial in the suspension, knew the springs I had were too weak, since I have considerable wait added to the frontend from the endura bumper, twin coolers, serp belt setup, and the intake setup.

Called up GW to get springs, and they sent me a set, and the thing was worse than the springs I had on it before. Called them, told them the car was sitting on the bump stops, and the guy (not Doug) told me it has to be something else, and asked me what kind of shocks I had. Um. Shocks don't hold the car up.

So they sent me another set. Just as bad. Called them back and told them that the springs that were on it before I started the resto were a little soft to begin with, and asked what those were (rate), and was told they were 680 lbs. Ok, then I need like a 750, or maybe even an 850, and was told it would be too much and they don't have any. AND, because I installed the sets I can't return them. (They used to accept them in the past).

Anyway, in a search for someone that could make springs to my specs, I found Coil Spring Specialties, and placed a build order for some 850 springs, 14" free height. That was calculated by using the previous springs as a baseline, and accounting for added weight on the front end. Those springs should be ready in about another 2-3 weeks.

In the interim, I ordered some off the shelf Afco springs that are 850, but are only 9.5" tall, which would require a spacer, which I also got, and adjustable one. I dialed the adjustment in order to achieve the desired 14" free height, but due to the shorter spring, rose the car too high, so dialed it to 13", which put the front end right where I wanted it, 1.5-2" lower than the rear.

I made several adjustments to the shock settings trying diff combos, and it's pretty close. I will have to try it with the new springs when they come in, since the spring is taller, and will respond diff than a short spring with a spacer. And no, it doesn't ride like a truck. It's stiff, but still does absorb bumps and tracks well.

So, I am pretty close to the desired setup, may drop back to a 750 lbs spring that's 15" or 16" free height, will just have to figure that out once I get the 850s.

As an example, the 560 lbs spring that I just removed, made the car rest on the lower control arm bumpers. The 680 lbs springs that were in it as it lived as a LeMans were the 680 lbs, and those would bottom and bounce off the lower control arm bumpers on dips and stuff. So I know I'm close with the 850s. Might need an 800 lbs spring, but will try a taller 750 lbs spring beforehand.

Also, as soon as I can, I will take the car to get it's corner weights on some race scales, so I know what I'm dealing with.

Questions/comments/suggestions are appreciated.

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Sounds like you're getting there. Coil springs can be a real pain in the a$$, can't they? Rare that I find some that are just right.

Any particular reason that you're not doing coil-overs? After what I went through with my '68 Lemans convt. a few years ago trying to find the right springs, I'll do coil overs on my next one.

[HWYSTR455]

The problem with coil springs is most are generic spun wire, and tolerances are all over the board. 'Accepted' tolerances are in the 8-12% range, which means for example, on a 500 lbs spring, can vary from 40 lbs - 60 lbs. Imagine if you have 2 springs at the end of the tolerances? 440 - 560 from side to side, and you get the dreaded 'lean'.

Coil overs. I asked that question in the 80s, and it was explained to me in this way:

The longer the piece of 'wire', the more granular the rate changes as it bends.

Imagine this. You have 2 identical thickness metal rods, one is 18" long, and the other 36". If you grab either, and you slowly apply pressure to bend them, the longer one begins bending 1st, right?

Traditional coil springs are 5" or 5.5" diameter. Most are in the 16-20" free height range. Traditions coil over springs are 2.5 diameter, and in the 10 - 14" range. If you take one of each, and straighten them into a rod, which one is longer?

Packaging coil overs and strut/spring assemblies is much easier and cheaper to use and produce. In a performance app, generally, above a certain weight, all the OEs use strut/spring combos, because the coil spring on a strut is much longer 'rod'. An exception is on lighter cars, and in canted/cam type suspensions.

GW is now crossing over to coil over setups, and it looks like they are basing it off the QA1 design(s), so if you want to go that route, the QA1 stuff is the best. The 'hybrid' setups with tapered springs, are basically a strut/spring setup. The 'Pro' stuff is cutting edge, excellent, but not cheap. That also is a factor for me, I already have an investment if the traditional coil spring suspension (control arms, bearings/bushings, etc). Each shock is around $2k ea, and you basically need to run their' control arms too. Front and rear kits are in the 7500 - $8400 range.

https://qa1.net/GM/Car/GTO/1968-1972/Handling-Kits/

Its still somewhat hybrid, the springs are still tapered, but it's built for heavier cars.


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[HWYSTR455]

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Here's the front end drop comparison, the 1st pic is with the 560 lbs springs, the 2nd with the 850 lbs springs.

EDIT: The 1st pic is with 275/40/18s, the 2nd is with 255/40/18s.


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[HWYSTR455]

Update:

So I installed new front and rear springs.

The fronts are 14" free height, rate is 850 lbs. In order to get the ride height where I wanted to start with I had to cut 1/2 a coil off. This puts my wheel opening edge at 24.75".

The rears are 12.5" free height, rate is 198 lbs. This gives me a wheel opening edge height of 26.75". This will probably relax a little more, and I only have a 1/2 tank of gas in it when I measured.

Ideally, I still would like the front to go down 1-1.5", and the rear 1.5-2". But going to drive it a while and see where it takes a set.

Driving Impression:

Much better control in all conditions, with only mild harshness on extremely bumpy roads. I drove many diff roads, harsh dips, uneven surfaces, washboards, railroad crossings, you name it, and it's not anywhere near as harsh as I thought it would be.

On the fronts, since I have the shock settings a little high/aggressive side, I could probably go to 875-925 lbs, and get more range of adjustments.

I still have minor wag-the-tail in the rear going over washboards and series of dips, so I could probably go up to 220 lbs in the rear, maybe 240 lbs.

Quick recap of current suspension:

GW control arms all around, del-alum bushings
Spherical joints in upper rear housing eyes
Solid body mounts
Speedtech AFX spindles
1.25" front sway bar
1" rear sway bar
QA1 double adjustable shocks set at compression 10, rebound 12, all four corners.


I will update this in a couple weeks with more driving as is.



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[HWYSTR455]

I was wanting to do corner weighing so I could have numbers to use certain calculators for selecting springs, and was able to get a total weighing done at a local truck scale.

On another thread that this came up on, I posted the following:

"So was having troubles scheduling my corner weighing with local shops, most scales cap out at 1000 lbs each, and felt I would exceed that. So I figured I would get a total weight as a starter.

I went to a truck scale, the scales have 3 pads, the 2 first pads ae a little closer together, guessing to be able to calculate cab weight, and be able to determine cargo weight with the 3rd pad.

So with me not in the car, 3/4 tank of gas, total weight came in at 4280, with a front/rear split of 2360/1920 respectively. (see attached pic)

Gas (90/10 ETH, depending on season) weighs an average of 6.2 lbs per gallon. Tank holds 6.2 lbs x 23 gallons (142.6 LBS), so minus 25% (35.65) of 23 gallons = 106.95 lbs, if I did that math right.

4280 -106.95 = 4176.05 lbs

Less than I thought, but, technically, since I'm calculating corner weights for actual driving conditions, I should be using full tank curb weight, which is measured weight of 3/4 tank adding the 1/4 tank of 35.65, for a total of 4315.62 lbs.

That is closer to my guess-timate, the truck scales may have been certified by %, and a 2000 lbs scale will have less of a variance than a 50,000 lbs scale. But it still gives me a ball park.

I will keep look for someone to corner scale for me so I can get more accurate numbers, just wanted to close the loop on this for this thread. "

Wanted to post here for reference.


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[HWYSTR455]

Quick update on what I've been working:

* Rear springs are becoming a challenge, but less so since I had it weighed. The 200lbs ones (198 technically) were obviously not going to work, ordered 250s, and they ended up an actual being 220. So I ordered 275s, which came in at 255, those too were way too soft. Finally, I ordered 400s, which came in at 405 and are MUCH better. Unfortunately, I still am maxed out on shock adjustment, and will have to step up another 50-75lbs. For now, it's livable and will deal with it, so moving on to other items in the mean time.

* The DBW throttle body and intake elbow I started with is a CTS-V 92mm and the Edelbrock Ultra Low Profile Intake Elbow. I knew it wouldn't be enough, and it starts pulling vacuum over 4K RPM. A lot, like 4-7" around 6k+ RPM.

Shopping for throttle bodies, I got a good deal on a 102mm, and since it would take considerable work getting it to work with my elbow, shopped that too. I found a sheet metal one made by 417 Motorsports, which is listed as a 'F-Body Low Profile' unit, and has high flow. It was reasonably priced, and had them install a bung on the underside in roughly the same location as I had before. I was able to relocate the MAP sensor to the underside as well, providing a cleaner look.

Have a couple minor other things to do, will knock those items out, load my mod'ed tune, and fire it up hopefully today.


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