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I'm putting a C4 front suspension into my trans am!!

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Old 02-25-2018, 01:16 AM
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Re: I'm putting a C4 front suspension into my trans am!!

Steering rack and lower A-arms in for good! Overall fit is excellent. Great clearance everywhere and the rack measures out perfectly level with the ground, just like the lower control arm mounts. Everything is shaping up perfect!
Attached Thumbnails I'm putting a C4 front suspension into my trans am!!-dsc02716.jpg   I'm putting a C4 front suspension into my trans am!!-dsc02717.jpg   I'm putting a C4 front suspension into my trans am!!-dsc02720.jpg  
Old 02-25-2018, 04:44 AM
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Re: I'm putting a C4 front suspension into my trans am!!

so how long before the test drive happens!!!!!!
Old 02-25-2018, 07:25 PM
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Re: I'm putting a C4 front suspension into my trans am!!

Upper A-arms now installed permanently with fresh bushings and ball joints, pass side turbo manifold back on along with plug wires and dipstick, and found that a 4th gen power steering line fits like it was made for the car...who woulda thought lol.

Originally Posted by Jaysz28
so how long before the test drive happens!!!!!!
If all goes according to plan...I'm staying hopeful that it'll be road worthy in a few weeks.
Attached Thumbnails I'm putting a C4 front suspension into my trans am!!-dsc02723.jpg   I'm putting a C4 front suspension into my trans am!!-dsc02724.jpg   I'm putting a C4 front suspension into my trans am!!-dsc02726.jpg  
Old 02-26-2018, 07:11 AM
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Re: I'm putting a C4 front suspension into my trans am!!

Leave the strut holes open, that will screw with anyone who does a quick look under there, that knows these cars, lol
Old 02-26-2018, 10:39 PM
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Re: I'm putting a C4 front suspension into my trans am!!

New vid

Originally Posted by scooter
Leave the strut holes open, that will screw with anyone who does a quick look under there, that knows these cars, lol
LOL, I would but the tops of my strut towers are ugly and beat to heck from the caster camber plates...better to just cover the ugliness up!

Old 02-27-2018, 08:13 AM
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Re: I'm putting a C4 front suspension into my trans am!!

Originally Posted by whitedevilTA
LOL, I would but the tops of my strut towers are ugly and beat to heck from the caster camber plates...better to just cover the ugliness up!
Put in a broken stock mount with the strut coming through it then
Old 02-27-2018, 12:17 PM
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Re: I'm putting a C4 front suspension into my trans am!!

Originally Posted by scooter
Put in a broken stock mount with the strut coming through it then
this x1000!

'I thought I heard a clunk on the way to the show'
Old 03-02-2018, 07:58 PM
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Re: I'm putting a C4 front suspension into my trans am!!

I want this info to be out there on the web because it just gave me a massive migraine trying to figure it out, and every forum I searched on had questions but no answers... Regarding bump steer kits on the corvette suspension, the corvette uses the same 1.5" per foot (listed as GM 10*) taper that every other GM vehicle uses. However, because the corvette spindles are aluminum, GM apparently sunk the taper in a bit deeper. For this reason, many aftermarket GM bump steer kits do not fully seat because they hit the integrated nut on the bump steer stud before the taper gets all the way in. My solution was to grind off the integrated nut on a bench grinder and follow the existing taper, essentially extending the tapered part of the bump steer stud. It now fully seats in the corvette spindle and fits like a glove, the way it should. Just have to add a second washer on the top side to compensate for the small end of the taper slightly protruding through. I'm also using a spohn bump steer kit for a 4th gen F-body, for reference.
Attached Thumbnails I'm putting a C4 front suspension into my trans am!!-dsc02735.jpg   I'm putting a C4 front suspension into my trans am!!-dsc02736.jpg   I'm putting a C4 front suspension into my trans am!!-dsc02738.jpg  
Old 03-03-2018, 01:12 AM
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Re: I'm putting a C4 front suspension into my trans am!!

Just a useful note: It is perfectly acceptable to just drill out the spindle to 5/8" and use grade8 bolts with 5/8" rod ends and spacers on the bolt. Makes life much easier in any GM application. You do not necessarily need to use a taper.

Project is coming along great (thumbs up)
Old 03-03-2018, 08:23 AM
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Re: I'm putting a C4 front suspension into my trans am!!

Originally Posted by SlickTrackGod
Just a useful note: It is perfectly acceptable to just drill out the spindle to 5/8" and use grade8 bolts with 5/8" rod ends and spacers on the bolt. Makes life much easier in any GM application. You do not necessarily need to use a taper.

Project is coming along great (thumbs up)
The standard bolt was an option that almost followed through during my head scratching, while trying to figure out the taper issue. I've always had a slight preference to a taper fit only because they eliminate any chance of play by design. But regardless, I'm glad this problem is behind me now!

And thanks, I'm getting extremely excited to start testing things out. Hopefully within a few weeks.
Old 03-03-2018, 08:38 AM
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Re: I'm putting a C4 front suspension into my trans am!!

Yes the taper IS in fact a safer design due to it "cinching" into place and the cotter pin. When you do a bolt I like to use one without a shoulder so I can run a washer and locknut all the way up under the spindle arm so as to permanently lock it into position- then run the spacers and rodend up against it and lucknut on the bottom. Your Meziere flared safety misalignment spacers are a piece of mind and a smart choice in a single shear application like that in case of ever a rodend failure it keeps everything together. I use them on my Mercedes rear suspension links I have in single shear.
Old 03-14-2018, 09:24 PM
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Re: I'm putting a C4 front suspension into my trans am!!

New vid Car is literally 3 parts away from being drivable!

Old 03-31-2018, 07:14 PM
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Re: I'm putting a C4 front suspension into my trans am!!

Gentlemen... test drive footage

The car feels transformed. I honestly don't even feel like I'm driving a 3rd gen. Steering is amazing - crisp, tight...no bumpsteer whatsoever. The ride is amazing, everything is amazing! I drove it probably 40+ miles today and I'm falling in love with the car all over again. It literally steers and feels like a modern sports car. The one thing I need to change is my wheel backspacing in front to get rid of the excessive scrub radius, but even that is not generally noticeable most of the time while driving. I am LOVING it!!!!

Old 03-31-2018, 08:51 PM
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Re: I'm putting a C4 front suspension into my trans am!!

Congratulations! I"m glad all of the hard work paid off.
Old 03-31-2018, 09:26 PM
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Re: I'm putting a C4 front suspension into my trans am!!

congrats. nice job
Old 04-19-2018, 06:52 PM
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Re: I'm putting a C4 front suspension into my trans am!!

White Devil TA
Cain't Say enough good about your talent, your build and your presentation. Enjoy a great car.
Having done one, if you were to build another would you do anything different?
Tex
Old 04-20-2018, 05:35 AM
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Re: I'm putting a C4 front suspension into my trans am!!

Congrats man!

I wish I had the skill and courage to do something similar to my car!
Old 01-01-2019, 10:16 PM
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Re: I'm putting a C4 front suspension into my trans am!!

Somehow your video showed up in my youtube feed, glad I saw it. I've wondered about racks going into our cars, though the lack of success generally kept me from looking into it, the only 'bolt in' options being drag only. Glad it worked out for you, any further follow up comments after driving it over the summer?

I'd love to do exactly what you did, but a small single car garage and no fab skills will make it hard

On a side note, how hard is it to not just light up the rears with the turbo, or are you just running drag radials?
Old 01-06-2019, 09:59 PM
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Re: I'm putting a C4 front suspension into my trans am!!

I see he has not answered after giving it a few days. He and I ended up conversing a lot on this and I did my best to help him with his desire. In the end he was happy with the overall outcome and I commend his fabricating skills and effort- His desire was to just have a decent cruiser and that he is happy enough with.

With that said, he did admit to me the car does want to yank the steering wheel under heavy braking on uneven surfaces just as I warned him this would do in my first post prior to him ever starting this project. For him? not a bad thing, he is content, but put that car on a track and he will have a handful under high speed braking. No bashing, just posting facts and actual final conversations he and I had about the outcome.

Dean

ps- only so much you can do with a specific tack width marrying it to another platform.
Old 01-07-2019, 11:44 AM
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Re: I'm putting a C4 front suspension into my trans am!!

Originally Posted by SlickTrackGod
With that said, he did admit to me the car does want to yank the steering wheel under heavy braking on uneven surfaces just as I warned him this would do in my first post prior to him ever starting this project. For him? not a bad thing, he is content, but put that car on a track and he will have a handful under high speed braking. No bashing, just posting facts and actual final conversations he and I had about the outcome.
Why is that?
Old 01-08-2019, 09:04 PM
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Re: I'm putting a C4 front suspension into my trans am!!

Originally Posted by scooter
Why is that?
I explained it in detail on page 1.

Edt to add- my very first couple of posts , before this project even started.
Old 01-09-2019, 10:08 AM
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Re: I'm putting a C4 front suspension into my trans am!!

Originally Posted by SlickTrackGod
I explained it in detail on page 1.

Edt to add- my very first couple of posts , before this project even started.
Thanks, I went back and read now. Honestly, I forgot you commented early on in the thread.
Old 01-10-2019, 02:18 PM
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Re: I'm putting a C4 front suspension into my trans am!!

Originally Posted by SlickTrackGod
I see he has not answered after giving it a few days. He and I ended up conversing a lot on this and I did my best to help him with his desire. In the end he was happy with the overall outcome and I commend his fabricating skills and effort- His desire was to just have a decent cruiser and that he is happy enough with.

With that said, he did admit to me the car does want to yank the steering wheel under heavy braking on uneven surfaces just as I warned him this would do in my first post prior to him ever starting this project. For him? not a bad thing, he is content, but put that car on a track and he will have a handful under high speed braking. No bashing, just posting facts and actual final conversations he and I had about the outcome.

Dean

ps- only so much you can do with a specific tack width marrying it to another platform.
Thanks for the reply, I had been 'hoping' that it wouldn't be a handful on track. While I don't often go to the track, I don't want to limit myself either. Also, there are times where you have to hit the brakes hard due to traffic/idiots/deer whatever on the street from possible highway speeds, so even if it's a street only car, still something to keep in mind. Being in Michigan, if a road is smooth now, give it a year or 2, tops, and you'll have all the uneven road you desire.

For those who like re-engineering cars and great fab work, I'd recommend looking up Project Binky on youtube. I haven't gone through the entire series yet, but the work they've done on the car is amazing.
Old 03-01-2019, 04:12 PM
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Re: I'm putting a C4 front suspension into my trans am!!

Sorry I haven't been on to reply. I don't visit TGO nearly as much as I used to. To answer any questions regarding the overall outcome and steering/braking feel, I am honestly in love with the front suspension. I have been tweaking it here and there as far as alignment specs, and ended up getting front wheels with a different offset to improve my scrub radius numbers. The wheels made a huge difference in reducing steering effort, and now during low speed turns, it has a firm sporty feel, but nowhere near "too" stiff.

As for braking, the car felt slightly unstable ONLY during braking while cornering. However, I noticed shortly after that I mistakenly set the alignment with way too much toe in (roughly 1/4" but it was purely by accident). When I finally noticed my mistake, I readjusted the toe to about 1/16" toe out and the stability during hard cornering braking feels excellent now.

Bump steer is virtually non existent, and I have had the car down some horrendous back roads filled with bumps and uneven road surfaces. At this point, I have about 1200 miles on the suspension and the car is a dream to drive vs the old factory style setup. In a racing environment, you may find issues since obviously this setup was designed around another chassis' geometry, but for my purpose of this car being 99% street driven, I am absolutely in love with the feel and wouldn't take it back for a second. It's amazing to be able to drive down backroads with a big 275 front tire and have the steering feel completely tight with no wander at all. And to be honest, in my opinion this suspension actually rides smoother than my particular stock style setup. It absorbs bumps amazingly well!
Old 03-04-2019, 02:27 PM
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Re: I'm putting a C4 front suspension into my trans am!!

Glad to hear you got it sorted out, that toe in will really make a difference! Any idea if the Hawks reproduction lace wheels are close to the right offset (at least compared to what you ended up with)?
Old 03-04-2019, 09:40 PM
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Re: I'm putting a C4 front suspension into my trans am!!

Awesome thread and build! Glad it turned out well for you - I thought I had learned a lot in recent years but the conversation here just made me feel like a 10 year old when it comes to suspension set up :/
Old 03-26-2019, 04:59 PM
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Re: I'm putting a C4 front suspension into my trans am!!

Originally Posted by V6canvas
Glad to hear you got it sorted out, that toe in will really make a difference! Any idea if the Hawks reproduction lace wheels are close to the right offset (at least compared to what you ended up with)?
Honestly no idea on the hawks wheels, but I'm assuming they are a 3rd gen type of offset which will probably be way off. The front wheels I'm running with this setup are 17x9 with a 6.1" backspace I believe. They are very close to 4th gen front wheels if I'm not mistaken.

Originally Posted by ughmas
Awesome thread and build! Glad it turned out well for you - I thought I had learned a lot in recent years but the conversation here just made me feel like a 10 year old when it comes to suspension set up :/
Thank you! Honestly, I learned a TON of new info during this project as far as suspension geometry goes. I thought I was pretty knowledgeable before, but once you dive into custom suspension, it's a whole new world!
Old 03-27-2019, 12:15 PM
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Re: I'm putting a C4 front suspension into my trans am!!

It's great to hear you have everything sorted out. Looking forward to getting mine on the road.




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