Pro-Touring Ttype Build

[turbobuick]

I thought I would post some pics of my Ttype which has been an on going 18 year project that is still a work in progress. It finally made its way to the dragstirip and on to a road course recently with some success . I am having a blast with this car this year and finally enjoying it more than working on it and for some reason this is one of those cars that has fought me every step of the way!

I've had this car since 2005. I did a complete frame off resto which I finished in 2011 then traded the car in 2013 and got it back in 2018 exactly like it was when it left and then proceeded to completely re-do the entire cars suspension, motor and drivetrain and this year I am finally finishing it and getting the car sorted out.
Deets:
Car is pretty well optioned and rare Canadian Import ehh! It was a mess when I found it as a roller but super clean and still wears all of its original sheetmetal. I preserved the car's originality as much as possible with the build, its really quite stock appearing other than the frame is 5.5" off the ground. All options work including AC and car even has all its factory jute padding weighing in at 3700# with driver and full tank of gas.
Motor is an mint off-center 0012 Stage 2 block with 4340 3.625 crank Oliver 6" Billet rods, J&E pistons
GN1R heads ported stock intake ported stock TB.
TA headers wtih 3 bolt PTE billet wheel 6768 3" THDP and 3" ATR crossflow exhaust
GN1 SLIC that gets quite toasty with this combo
Janis billet rollerized 200r4 Bradco TQ
Denny's 3.5" alum shaft with 1350 Ujoint and billet yokes
Stock 8.5" rear with 30 spline Mosers, and rebuilt/upgraded GM carrier
ECUGN with flex fuel on Corn
Racetronix 750l fuel system and fuel lines 120# injectors
Cooling is Champion radiator with twin spal fans with int oil and trans coolers and one external trans cooler and a power steering cooler I am in process of installing. The radiator is bad ass car is never over 175 even getting off the road course after a 20 minute session!

Front suspension is Ride Tech TruTurn UCA/LCA made to work with Viking DA coil overs 550# springs and RideTech 1.5" Musclebar front sway bar.
Rear Suspension HRparts UCA/LCA with UMI adj rear roll bar and UMI rear coilover conversion with Viking DA Coilovers with 125# springs (but going to 175)
Brakes: Baer 12" rear SS4+ and currently the 11" Baer SS4+ fronts but they are sending me parts to convert to 12" in front.
Wheels, early GTA two piece wheels I had machined and polished repainted they were originally grey GTA wheels and match the car. I had the rear cut apart and re-welded to deeper offset. I have 6 wheels total with Toyo R888Rs 245/255 for road/autox and a pair of Toyo 275/45 DR on the other two which work ridiculously well even on the street.

I built this car to do it all!. I showed it at BG this May. I drove to the drag strip a few weeks ago on a Wed night TT, and ran 10.75 and drove off the track and drove home. I ran the car exactly like the car is driven on the street, same gas in the tank (pump E85) and tires on the car. A week later I changed out the rear drag radials tighened up the coil overs and took it road racing! I have the NE Musclecar Challenge coming up this Thurs to Sat at Pitt-Race. This is road racing and auto-X event for 1987 and older American made cars with V8s and one V6 lol!

 

[Danster]

Nice Stance!
What modifications were required to make this setup work together? Front suspension is Ride Tech TruTurn UCA/LCA made to work with Viking DA coil overs 550# springs and RideTech 1.5" Musclebar front sway bar.

 

[turbobuick]

Nice Stance!
What modifications were required to make this setup work together? Front suspension is Ride Tech TruTurn UCA/LCA made to work with Viking DA coil overs 550# springs and RideTech 1.5" Musclebar front sway bar.

Thanks, its not easy getting them to sit like that it takes a lot of massaging of parts, especially the exhaust, to get everything to fit without rubbing. This car actually rides pretty decent too, not to bouncy and nothing rubs. There are a few tricks and like any build there are some things I would do differently.

If considering a build like this you need to check out turbo6inky blog. He has given me a lot of very valuable advice and help and I am grateful for the info he has shared. His blog and youtube channel have many informative articles on building a pro-touring suspension in a Grand National.

The Buick Build Sheet! | Things I work on

Andrew's Blog of stuff

www.andrewdscott.com

Now for my build:
I would not have used the RideTech arms and went with UMI. The ride techs lowers are made to work with their single adj coil overs and I had to make bushings for the lower mounts to make the Vikings fit. It wasn't a big deal they were just 3/8 alum spacers but I would not have had to do that with the UMI set up plus the UMI lowers with the CO mount make it easy to swap springs and CO with the removable mount.

I for sure would have gone with the UMI adjustable race UCAs and most likely going to switch to them. They use a rod end upper bushing and eliminate the delrin bushing that the headers and DP like to melt. i have not had an issue with the Delrin bushing in my Ridetech's yet but only have one track outing on the car so far, again Turbo6inky has a bunch of posts on his site about the issue and has run a few different UCA setups.

More importantly it is difficult to get an aggressive alignment with the RideTech UCAs. I have over a 1/2" of shims for 5.5* of caster and only -1.5* of camber and will run out of room for shims to get over 2* of camber. I spent an entire day doing the alignment on the car and messing with the stupid caster slugs they use and I had to order from Ridetech. I would like to have 7* of caster and -2* of camber.

Sway bars, from what I have gathered you want as big a swaybar on the front as possible and a small diameter one on the rear. Again check out the custom one Turbo6inKY built for his car on his blog site. The Musclebar from Ridetech is the largest one you can buy and bolt on and is pretty nice piece. I am not a fan of the end links they use, I had one break and if I break another I will probably fab something heavier duty with rods ends.

The UMI rear is .75" and adjustable and bolts to the frame like the HRparts bar. It helps with cornering to use a smaller rear bar so you dont lift the inside rear tire. A lot of guys switch to a Watts Link or panhard bar rear suspension set up on the Gbodys.

The only other thing I would have done differently is NOT run 16" rims, tire and brake size and availability are limited and tires and brakes are the most important parts for a car you plan to autox or road race! Gbodyparts came out with the 18" GNX repops after I finished my car I would have never put the money into the GTA wheels if they were available when I built my car. Brakes were an issue for me at the track and faded really bad coming off the front straight into turn 1 at Pitt-Race. I had drums on the rear at the time and since put the 12" Baer SS4+ rear disc set up on. I still have the 11" SS4+ rotors on the front but Rick Elam at Baer made up a 12" rotor kit they are going to start selling and I am waiting on the parts to show up to convert the fronts. I also need more spring in the rear and planning to switch to 175# from the 125s I have now. I believe turboinky runs 700/220 but I am not planning to compete with this car just have fun at open track days and maybe occasional autox event.

 

[toofastforyou]

In the second picture, is that a power steering reservoir?... There is a letter "K" on it but who makes it?
Thanks,
Claude.

 

[turbobuick]

In the second picture, is that a power steering reservoir?... There is a letter "K" on it but who makes it?
Thanks,
Claude.

It is my new reservoir. I haven't installed it yet but got the cooler hooked up for tomorrows road race event. I found it on Summit's site and I believe it is going to bolt right in I think I am even going to use the factory bracket.

https://www.summitracing.com/parts/KYS-100-15382

 

[vicious6]

I thought I would post some pics of my Ttype which has been an on going 18 year project that is still a work in progress. It finally made its way to the dragstirip and on to a road course recently with some success . I am having a blast with this car this year and finally enjoying it more than working on it and for some reason this is one of those cars that has fought me every step of the way!

I've had this car since 2005. I did a complete frame off resto which I finished in 2011 then traded the car in 2013 and got it back in 2018 exactly like it was when it left and then proceeded to completely re-do the entire cars suspension, motor and drivetrain and this year I am finally finishing it and getting the car sorted out.
Deets:
Car is pretty well optioned and rare Canadian Import ehh! It was a mess when I found it as a roller but super clean and still wears all of its original sheetmetal. I preserved the car's originality as much as possible with the build, its really quite stock appearing other than the frame is 5.5" off the ground. All options work including AC and car even has all its factory jute padding weighing in at 3700# with driver and full tank of gas.
Motor is an mint off-center 0012 Stage 2 block with 4340 3.625 crank Oliver 6" Billet rods, J&E pistons
GN1R heads ported stock intake ported stock TB.
TA headers wtih 3 bolt PTE billet wheel 6768 3" THDP and 3" ATR crossflow exhaust
GN1 SLIC that gets quite toasty with this combo
Janis billet rollerized 200r4 Bradco TQ
Denny's 3.5" alum shaft with 1350 Ujoint and billet yokes
Stock 8.5" rear with 30 spline Mosers, and rebuilt/upgraded GM carrier
ECUGN with flex fuel on Corn
Racetronix 750l fuel system and fuel lines 120# injectors
Cooling is Champion radiator with twin spal fans with int oil and trans coolers and one external trans cooler and a power steering cooler I am in process of installing. The radiator is bad ass car is never over 175 even getting off the road course after a 20 minute session!

Front suspension is Ride Tech TruTurn UCA/LCA made to work with Viking DA coil overs 550# springs and RideTech 1.5" Musclebar front sway bar.
Rear Suspension HRparts UCA/LCA with UMI adj rear roll bar and UMI rear coilover conversion with Viking DA Coilovers with 125# springs (but going to 175)
Brakes: Baer 12" rear SS4+ and currently the 11" Baer SS4+ fronts but they are sending me parts to convert to 12" in front.
Wheels, early GTA two piece wheels I had machined and polished repainted they were originally grey GTA wheels and match the car. I had the rear cut apart and re-welded to deeper offset. I have 6 wheels total with Toyo R888Rs 245/255 for road/autox and a pair of Toyo 275/45 DR on the other two which work ridiculously well even on the street.

I built this car to do it all!. I showed it at BG this May. I drove to the drag strip a few weeks ago on a Wed night TT, and ran 10.75 and drove off the track and drove home. I ran the car exactly like the car is driven on the street, same gas in the tank (pump E85) and tires on the car. A week later I changed out the rear drag radials tighened up the coil overs and took it road racing! I have the NE Musclecar Challenge coming up this Thurs to Sat at Pitt-Race. This is road racing and auto-X event for 1987 and older American made cars with V8s and one V6 lol!

Very nice and tare car! Great job!

 

[JDSfastGN]

I don't get on the forums a ton anymore but just wanted to say this is a badass build that deserves a ton of credit. Its awesome to see a Buick Gbody on the road course. I hope to make ti BG in 23 and would love to see this car in person.

 

[turbobuick]

I don't get on the forums a ton anymore but just wanted to say this is a badass build that deserves a ton of credit. Its awesome to see a Buick Gbody on the road course. I hope to make ti BG in 23 and would love to see this car in person.

Thanks!

I had the T-type at BG last two years this year I am hoping the GN will be done. Considering I registered the GN for SIck Week in Feb I am hoping it will make BG in May lol!!

If I can figure out how to get two of them down there I will.

Update on the T-type after the NE Musclecar Challenge. That was a really cool event and the level of quality and performance of the cars you see at these pro-touring events is incredible. I learned a lot and found many many issues with the car I need to address for next year. While I did have fun the event did not exactly go as I had planned. I caught the damn car on FIRE!!!

I was lucky, I mean REALLY lucky as there is minimal damage to the car out side a huge mess a few singed wires and conduit. The hood pad was toast and the trans had expired. The trans caused the fire as it over heated and vented most of it fluid out on to the exhaust which caught fire on the front straight at 120+ MPH going into turn 1, fun stuff. It was the second run session and I was just getting rolling on a pass by. I was on on the gas when the car nosed over and I saw a bunch of white smoke in the rear view mirror. I knew to get off the track immediately and as I pulled into the in field I saw flames out the back of the car. I shut the car off and got out which the only time your allowed to do this on a road course is if your on fire!! As I got out the emergency crew was already coming down the hill as they saw what happened and were already in motion. I was standing there just waiting to see paint bubble up on the hood while smoke was bellowing out everywhere. When they got there they sprayed the underneath of the car and then I opened the hood and a huge fireball erupted and was quickly extinguished. The track used a suppressant called FR500 which leaves an oily residue everywhere but does not damage or stain anything. I was able to get the car home clean it up fix most of the damage replace the trans and actually made it back to the event for the final day of Autocross!!

You can't tell looking at it today that it even happened, there is still some mess underneath the car I plan to clean up this winter. The passenger side floor pan is singed pretty bad and will need sanded down and repainted. Of all things the passenger tailight lens is faded and has heat cracks in it from the fire so I am going to replace both of them this winter too. Paint is perfect. I posted pics of it after the fire and two days later. I actually found a mint 9 hole hood pad in my attic I didnt even realized I had lol!

Lessons, things to fix:
1. Safety equipment, My GN has a full 25.3 spec cage fire suppression, kill switch, etc. My road race car, nothing!!! Road racing is WAY more dangerous than even high level drag racing and I can not believe how much of an idiot I was with out any significant safety gear. I did not want to cut this car but if I continue to track it, it is getting a 4 pt road race bar, safety harness, kill switch and fire suppression.

2. While the 6768 turbo and Bradco converter in the car work well on the drag strip they were just wrong for the track and Auto X. 800 HP is cool to have but totally worthless in a Regal on a road course with a driver who at most needs 300hp. The turbo/conv just made to much heat and the 6768 turbo while it spools fast it does not transition fast which really hurt it on the Auto X portion. I am still deciding on what TQ to go with Vince just got the trans apart and it got really hot I posted some more destruction pics below lol. I am going with the new HPT 6466 turbo Mike Licht is promoting and Harry's new business adventure. I am also going to an external WG with the new turbine housing which is pretty cool but I need to make it fit with a SLIC

4. Bigger Transmission cooler! I am going to add an external oil cooler too, actually I am going to make the current ext trans cooler an oil cooler and move the new 4" thick twin fan monster trans cooler to the rear of the car somewhere lol!

5. Instrumentation, I have a ECUGN in the car and a Scanmaster G which keeps my dash very clean and stock looking which I like. I am going to wire up some of the stock idiot lights as temp warning lights on the dash. Gauges are useless on the track as you are constantly looking everywhere to begin with.

SO, as you can see I have a lot to do and plan to start as soon as I am done with my GN project which if I plan to make Sick week needs to be running by December. I may make a build post about it soon. I am taking the T-type to SC on Nov 10th for the SteetNYeet Drag n drive event. It is a 4 day event which I am looking at as a practice run for Sick Week. I am going to take the race trailer I have for the GN, the Ttype should be able to make that drive pretty easily and I dont plan to run it hard on the drag strips which I think are all 1/8 mile. Hell I plan to do the whole thing without changing tires!

 

[1986 Buick GX1]

Holy smokes.!! I’m glad you are alright and the car wasn’t hurt too bad. I’m sure it was insanely intense.

Are you switching to the 175 lb rear springs due to understeer?

 

[turbobuick]

Holy smokes.!! I’m glad you are alright and the car wasn’t hurt too bad. I’m sure it was insanely intense.

Are you switching to the 175 lb rear springs due to understeer?

TBH when I was standing there watching the car burn I felt like a idiot. It wasn't my first time on fire in a race car nor off course or even crashing, I knew better. I can't stress how important safety is and how unimportant the car actually is.

The issues with suspension set up with this car became VERY apparent on the AutoX course. The rear is just way to loose and the turbo is just wrong. I am working up on springs. Started with 450/125 now at 550/175 and ideal is probably 700/225. But I am trying to find that happy medium for street, drag strip and track.

 

[TType85]

Awesome build. Both yours and Turbo6inKY builds are great inspirations to show that these car's aren't just for drag racing I have a ways to go to dial in everything on my car but I hope to have it out doing some auto-x and road course in the future.

More importantly it is difficult to get an aggressive alignment with the RideTech UCAs. I have over a 1/2" of shims for 5.5* of caster and only -1.5* of camber and will run out of room for shims to get over 2* of camber. I spent an entire day doing the alignment on the car and messing with the stupid caster slugs they use and I had to order from Ridetech. I would like to have 7* of caster and -2* of camber.

I can see what you are saying on the Ridetech front a-arms. I was looking at the alignment shims that were in and it seemed excessive. I was hoping it was just a bad alignment guy....

2. While the 6768 turbo and Bradco converter in the car work well on the drag strip they were just wrong for the track and Auto X. 800 HP is cool to have but totally worthless in a Regal on a road course with a driver who at most needs 300hp. The turbo/conv just made to much heat and the 6768 turbo while it spools fast it does not transition fast which really hurt it on the Auto X portion. I am still deciding on what TQ to go with Vince just got the trans apart and it got really hot I posted some more destruction pics below lol. I am going with the new HPT 6466 turbo Mike Licht is promoting and Harry's new business adventure. I am also going to an external WG with the new turbine housing which is pretty cool but I need to make it fit with a SLIC

It will be interesting to see how the new HPT 6466 turbo does. Pretty cool to see a *new* 3-bolt housing with an integrated stub for an external gate. With your motor it will probably be insane. I am downsizing to a Garrett G30-900 from a JB 6766 for the same reason; sacrifice some top end for transient response.

 

[turbobuick]

Awesome build. Both yours and Turbo6inKY builds are great inspirations to show that these car's aren't just for drag racing I have a ways to go to dial in everything on my car but I hope to have it out doing some auto-x and road course in the future.


I can see what you are saying on the Ridetech front a-arms. I was looking at the alignment shims that were in and it seemed excessive. I was hoping it was just a bad alignment guy....


It will be interesting to see how the new HPT 6466 turbo does. Pretty cool to see a *new* 3-bolt housing with an integrated stub for an external gate. With your motor it will probably be insane. I am downsizing to a Garrett G30-900 from a JB 6766 for the same reason; sacrifice some top end for transient response.

Thanks, I like your ttype too very similar to what I have. Andrew (Turbo6inKy) is definitely a pioneer in the GN pro-touring USCA world and has given me a TON of valuable advice along the way some of which I should listen to a little more carefully.

The UMI race UCA are really nice and on my upgrade list. With my ridetechs I got my alignment to 5.5 caster and 1.5 neg camber and have over 1/2" of shims in the arms with the 1/4 caster slugs installed. I was looking to add solid alignment shim stack like the ones Allstar makes but no one makes them to fit the GM metric frame they are all for earlier A-body frames.

That G30 was on my short list but felt the G35 might have been a better choice for my combo. I was planning to whack the 3 bolt flange off my TA headers and weld on a Vband and add an ext WG port and fab a new DP. The HPT exh housing makes that a bolt on with a block off plate for the THDP. Plus I have a 44mm Tial gate sitting here I am not using which should also bolt on. The only issue I see is it might not clear a SLIC so I will still have to fab an elbow to make it fit. I am excited about the turbo, I am sure Harry is going to produce a killer turbo for the Buicks.

 

[TType85]

That G30 was on my short list but felt the G35 might have been a better choice for my combo. I was planning to whack the 3 bolt flange off my TA headers and weld on a Vband and add an ext WG port and fab a new DP. The HPT exh housing makes that a bolt on with a block off plate for the THDP. Plus I have a 44mm Tial gate sitting here I am not using which should also bolt on. The only issue I see is it might not clear a SLIC so I will still have to fab an elbow to make it fit. I am excited about the turbo, I am sure Harry is going to produce a killer turbo for the Buicks.

Yeah it might be real close with the SLIC; the externa wg is well worth the effort to make it fit though. Boost control with one is a lot easier. The G35 would be awesome on your combo but the minimal fabrication needed on the HPT setup is a huge plus. Since I am not going for hero dyno numbers I figured the G30-900 should do good with the motor I have; cnc irons, small flat tappet cam, stock CR plus I was able to get it with an undivided T4 .82 housing and I have 4-bolt headers so it is mostly a bolt on; the one for the G35 is not going to be out till next year.

 

[1986 Buick GX1]

TBH when I was standing there watching the car burn I felt like a idiot. It wasn't my first time on fire in a race car nor off course or even crashing, I knew better. I can't stress how important safety is and how unimportant the car actually is.

The issues with suspension set up with this car became VERY apparent on the AutoX course. The rear is just way to loose and the turbo is just wrong. I am working up on springs. Started with 450/125 now at 550/175 and ideal is probably 700/225. But I am trying to find that happy medium for street, drag strip and track.

Did adjusting the rear sway bar to the front holes help?

I installed Herb Adams/ Moroso sway bars (1.31” solid front w/ spherical end links, 1.5” solid rear lower control arm mounted) in ‘88 along with ATR Performance front handling springs and Moog cargo coils in the rear. With 255/50-16’s all the way around I had perfectly neutral steering.
I installed Kenne-bell lift bars in the mid 90’s that I believe is the cause of my oversteer.
I haven’t pushed the car that hard in the corners for way too long and was trying to figure out what I changed.
I installed the UMI lower control arms and I’m trying to get back to that neutral steering.

It looks like you have lower control arm relocation brackets, but that my be your coilover mounting brackets. It’s hard to tell.

It seems Speedtech likes to run a smaller rear sway bar with stiffer rear springs and Hotchkis likes to run a larger rear sway bar with softer rear springs.

It’s definitely a balancing act.

 

[turbobuick]

Did adjusting the rear sway bar to the front holes help?

I installed Herb Adams/ Moroso sway bars (1.31” solid front w/ spherical end links, 1.5” solid rear lower control arm mounted) in ‘88 along with ATR Performance front handling springs and Moog cargo coils in the rear. With 255/50-16’s all the way around I had perfectly neutral steering.
I installed Kenne-bell lift bars in the mid 90’s that I believe is the cause of my oversteer.
I haven’t pushed the car that hard in the corners for way too long and was trying to figure out what I changed.
I installed the UMI lower control arms and I’m trying to get back to that neutral steering.

It looks like you have lower control arm relocation brackets, but that my be your coilover mounting brackets. It’s hard to tell.

It seems Speedtech likes to run a smaller rear sway bar with stiffer rear springs and Hotchkis likes to run a larger rear sway bar with softer rear springs.

It’s definitely a balancing act.

It is and TBH I am still figuring it out myself. I set the bar up like Ramey at UMI told me. He likes the rearend loose on a Gbody. There are a lot of opinions on what works on a Gbody rear suspension with the latest and greatest being a 3 link set up. I found a bunch of good info in this thread.

Rear 3-link

Im bored and fingers crossed going on unemployment soon, so in the spirit of Bobs spring thread and the other well written stuff on here, lets see if I cant string some cohesive thoughts together. Similarly in the spirit of the board feel free to jump in, none of that "stay off my...

www.montecarloss.com

Yes the UMI brackets lower the LCA mounting point which helps with IC and AS when you lower the car. They are also mounts for coil overs. If you want a CO mount that keeps the stock LCA bar angle look at the ones from Trick Chassis. The UMI ones work pretty well on a light foot brake launch high 1.50s low 1.60s 60s are pretty easy with this set up.

I think the UMI rear bar is the way to go as the rear suspension on a gbody can bind up pretty easily so most leave it loose. I think most agree to run the biggest front sway bar you can. I have the 1.5" Ride Tech musclebar.

 

[turbobuick]

Well look what showed up today!

 

[1986 Buick GX1]

It is and TBH I am still figuring it out myself. I set the bar up like Ramey at UMI told me. He likes the rearend loose on a Gbody. There are a lot of opinions on what works on a Gbody rear suspension with the latest and greatest being a 3 link set up. I found a bunch of good info in this thread.

Rear 3-link

Im bored and fingers crossed going on unemployment soon, so in the spirit of Bobs spring thread and the other well written stuff on here, lets see if I cant string some cohesive thoughts together. Similarly in the spirit of the board feel free to jump in, none of that "stay off my...

www.montecarloss.com

Yes the UMI brackets lower the LCA mounting point which helps with IC and AS when you lower the car. They are also mounts for coil overs. If you want a CO mount that keeps the stock LCA bar angle look at the ones from Trick Chassis. The UMI ones work pretty well on a light foot brake launch high 1.50s low 1.60s 60s are pretty easy with this set up.

I think the UMI rear bar is the way to go as the rear suspension on a gbody can bind up pretty easily so most leave it loose. I think most agree to run the biggest front sway bar you can. I have the 1.5" Ride Tech musclebar.

I feel the change to instant center is a benefit on the launch, but I think it’s the reason the rear is loose.
I changed to 255/40-17’s front and 275/40-17’s rear around the same time, it didn’t seem like the tire change should make a big difference so that’s why I suspect the lift bars/ IC change.
I’m updating suspension stuff, building an exhaust and other things so it’ll be a while before I can test my suspensions.

 

[TType85]

The only thing I don't like about the external gate on the housing is the sharp 90deg turn to get out to the wastegate. It is probably still 100% better than using the internal gate though. It's a nice looking unit.

 

[Turbo6inKY]

I feel the change to instant center is a benefit on the launch, but I think it’s the reason the rear is loose.
I changed to 255/40-17’s front and 275/40-17’s rear around the same time, it didn’t seem like the tire change should make a big difference so that’s why I suspect the lift bars/ IC change.
I’m updating suspension stuff, building an exhaust and other things so it’ll be a while before I can test my suspensions.

A few things:

1) Loose is fast on these, but loose enough for an autocross may be too loose to be safe on the street.
2) Tires are everything. If it's different and you changed the tires, it's the tires.
3) IC changes by themselves won't mess with "handling". You need to pay attention to the anti-squat percentage that results from the IC change. If you get above 100% anti-squat, it'll wheel hop violently under braking and start snapping shit off.

 

[1986 Buick GX1]

A few things:

1) Loose is fast on these, but loose enough for an autocross may be too loose to be safe on the street.
2) Tires are everything. If it's different and you changed the tires, it's the tires.
3) IC changes by themselves won't mess with "handling". You need to pay attention to the anti-squat percentage that results from the IC change. If you get above 100% anti-squat, it'll wheel hop violently under braking and start snapping shit off.

Thank you for your insight.