88 Cradle Swap thread
Printed From: West Coast Fieros
Category: General Fiero Chat
Forum Name: General Talk about Fieros
Forum Description: Just want to chat about fieros? here's the place to make that happen.
URL: http://www.westcoastfieros.com/forum/forum_posts.asp?TID=528
Printed Date: 22 November 2024 at 11:20am
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Topic: 88 Cradle Swap thread
Posted By: CFoss
Subject: 88 Cradle Swap thread
Date Posted: 04 April 2008 at 9:08am
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Anyone know where I can find a build thread for a 88 cradle swap. I looked on Pennocks but I keep coming up with engine swaps on 88 cars!
Thanks,
Chay ------------- 86 SE 3.4 |
Replies:
Posted By: Dr.Fiero
Date Posted: 04 April 2008 at 5:31pm
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It's not that hard a swap depending on how 'crafty' you are. Do you have a way to do some of your own steel fab work? If so, you can save a STACK and do a better job (IMHO) than going through Held for there (overpriced crappy) kit. |
Posted By: Roadfury
Date Posted: 04 April 2008 at 7:45pm
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why would you want to do the 88 swap? what advantages are there? ------------- 
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Posted By: Dr.Fiero
Date Posted: 04 April 2008 at 8:32pm
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MAJOR improvement in handling - the 88 is just totally superior. I've got it in the back of my '87, and it's the best handling car I've driven (still has semi stock front). |
Posted By: CFoss
Date Posted: 05 April 2008 at 12:38am
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Yeah, I can weld (I have a 250 A AC ARC and a 150 MIG) and have access to basic tools like a grinder/metal cutting disk and a metal lathe, powder coater for finishing etc. I saw on Pennocks (I think) that someone was talking about cutting a long thin triangle out of the early struts, then rewelding them and relocating the strut mounts on the top end, but the write up was lacking in dimensions/measurements. I found it hard to picture exactly what was needed to do the job to an appropriate level of accuracy. Perhaps you can shed some light on this? I wouldn't mind saving the 300+ bucks, plus, once I do it I can help others with the same if they want. Chay ------------- 86 SE 3.4 |
Posted By: CFoss
Date Posted: 05 April 2008 at 12:42am
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One more thing...I'm doing a total tear down so I may attempt the front 88 suspension as well. I have the front complete cali to cali, so I have most of what I need I think. I'll be documenting each step in the process for swap, with tons of pics etc. Chay ------------- 86 SE 3.4 |
Posted By: Roadfury
Date Posted: 05 April 2008 at 9:00pm
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Why does it do that? Is it just more stiff? lighter? if its just more stiff could you brace the 84-87 cradles differently? -------------
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Dr.Fiero wrote:Posted By: Dr.Fiero
Date Posted: 06 April 2008 at 2:07pm
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You'd have to see them side by side, and know how the geometry of suspension works to see/understand why it's so much better. I honestly wouldn't bother with the front though. In a lot of ways, I prefer my '87 over my '88 steering wise. It responds a lot quicker, and just feels better (though the '88 is much lighter steering wise). As for dimensions for the conversion - All you really need is a pair of cars sitting side by side, and you can get the measurements off 'em. Then, the way *I* was going to do the backend, was to use the way Held did it (with a modded strut, and coil over kit), but then intead of the way they make you cut out the top of your strut tower (yuck!), you'd make a plate that fits in the stock location (with studs sticking up as usual), then have a 2nd strut plate below it with the tipped in/fwd location of the 88 setup. Few (5?) tubes connecting the 2 plates together. A hole in the bottom plate to mount the strut to, and a larger hole in the top plate to let you get to the nut. The strut starting its travel position lower down is no big deal, as the thing barely moves at all with 350lb springs anyhow. That of course is just the basic concept in my head.
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Posted By: CFoss
Date Posted: 07 April 2008 at 9:01am
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Ok. I'm not sure I like the fact that the strut would be lower (Inducing a slight rake would be cool though). So, what you have written has me asking a few questions...
I get the fact that I need to relocate the strut mounts in order to attain the correct allignment etc for the rear end, and that this causes an interference with the spring on the strut. What I don't understand having not seen an 88 is what is the difference that causes this interference fit? Is the shape of the 88 frame different in this area (I was told they were pretty much the same) or is the wheel well area different on the 88 or both? I like the idea of the stock looking upper end though. Also, I have the 88 struts as well...could these give me some advantage? They don't look a lot different in legth or spring diameter but I'll check them closer as I go along here.
Chay ------------- 86 SE 3.4 |
Posted By: Dr.Fiero
Date Posted: 07 April 2008 at 5:30pm
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By the strut being lower, I mean it would simply start off lower in the travel of the piston. Doesn't matter anyhow. The stock position of the 88 strut is further inboard, and sits forward of an early car (it looks the same, just sits in a different location in space). To get the 88 strut to sit in the correct position of an early car strut tower, you need to go into a coil over - since any stock coil would be too large to fit otherwise. Ok, here's a shot of my relocated strut tower:  You can see the circled areas, red was where it started, and in green where it is now - this at least shows the relative positions of the two , and how BUTT UGLY it ends up being! Here's what the kit, and coil overs looks like (boy am I glad I took all these shots over the years):  That explain it better? |
Posted By: CFoss
Date Posted: 07 April 2008 at 6:50pm
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I think I'm with you now. When I get closer to doing the swap I may ask you to run a tape measure beside your relocation to help me solidify the location change. It looks very similar to what I found in a pic in this article: http://www.martinwhite.name/fiero/88cradle/index.html By lower in 'the piston' I supect you mean the height is adjustable somehow (I'm new to struts with coil overs). Anyway, I'll put the stuff together on the ground and figure it out. I have some reading to do. I have to admit, I'm kind of on the fence. It's only $300 bucks for the pre engineered version, and it would save a lot of time, even if it's a bit ugly. I get where you're coming from though. We'll see how much time it takes to figure out. Too much time and I'll just get the kit and move on to driving the car! I see that the strut shaft comes through the tower by about 1" or so it looks in your pic. I guess then if I made a plate which relocates forward, and in, and down then it would need to be about 1-1.5" below the current tower level, and then as you suggest, drill a large hole in the existing tower to access the nut where the shaft comes through it. Comments? Chay ------------- 86 SE 3.4 |
Posted By: Dr.Fiero
Date Posted: 07 April 2008 at 7:43pm
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What you could also do to save SOME of the engineering, is take the Held kit, and use it as a starting point. Just make my 'upper plate', and graft it onto the Held kit. Then you keep your stock appearance, but still get the relocation. To make up for the (arbitrarily say 2" lower position) you just get 2" shorter springs. If it's 1.75" lower, you get a 2" shorter spring and twist the ring up .25" until you're level (or down, or whatever it takes). Other bonus, if you add something that makes a corner heavy, you can twist it up/down to compensate. |
Posted By: CFoss
Date Posted: 09 April 2008 at 5:28pm
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Ok, got it now. I read a 'make your own coil overs' thread on Pennock's and now I understand that the ride height is determined by the spring length and the shock comresses to that height. I'll have to figure out the travel length in the shock...However much I remove off the height will make it that much closer to bottoming out. Chay ------------- 86 SE 3.4 |
Posted By: CFoss
Date Posted: 09 April 2008 at 5:30pm
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One more question...why 350lb springs? The stock ones are about 150#/inch (So I've read) so why so much heavier?? I don't have more weight in the rear end with the 3.4. Chay ------------- 86 SE 3.4 |
Posted By: Dr.Fiero
Date Posted: 09 April 2008 at 6:54pm
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I actually have 400's! Yeah, they're stiff.... But the springs I have in the front are stupid hard as well, so I needed to balance it out (don't want one end twisting and the other not!). I'd do 300's next time, maybe 350's. But I like a firm ride. If I want a Caddy ride... I'll go buy another caddy....  |
Posted By: Dr.Fiero
Date Posted: 09 April 2008 at 6:57pm
That'll depend a lot on which springs you use. Mine move, oh.... 1/4"-1/2" under a HARD corner! Heh... The strut piston has something like 10" of working stroke. I think you'll be OK. |
Posted By: marcelvdgn
Date Posted: 09 April 2008 at 10:22pm
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John..... whats your opinion on using the standard 86/87 location for the strut top of a SE coupe with the 88 lower suspension and cradle. i know the geometry would change and possibly the ride, but willl there be some interference?????? problems???? Marcel ------------- Marcel 86SE V6 Auto 85SE V6 Auto 85 2m4 soon to be sleeper 3.8sc 5 speed |
Posted By: Dr.Fiero
Date Posted: 10 April 2008 at 7:19am
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Frankly, I don't think it would work. As you say, even if you COULD ram it in there, you just killed the caster setting, and made it about 15* positive camber! Doubt you could adjust that out. |
Posted By: Borteep
Date Posted: 10 April 2008 at 3:20pm
At that point I would wonder why you were bothering with the switch to begin with. The whole point with going to 88 suspension is that it has improved geometry... so if you completely compromise that improved geometry by mounting it wrong... |
Posted By: marcelvdgn
Date Posted: 10 April 2008 at 10:19pm
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After reviewing John's photos i realized the extent of the geometric changes moving the top of the strut tower. (using the stock 84/87 position wouldn't work well.) hey just thinkin outload, and this is what this group is all about, its all good!!! M ------------- Marcel 86SE V6 Auto 85SE V6 Auto 85 2m4 soon to be sleeper 3.8sc 5 speed |
Posted By: Capt Fiero
Date Posted: 14 April 2008 at 8:27pm
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I had a giant 2 page reply wrote up. Then went to hit the backspace to edit something, and it shot back the entire web page and cleared my entire reply. FRACK.
So here is the short version. 88 Suspension Great, but REALLY expensive. Roughly 10x the price of 84-87 parts. 85GT can be made to handle as well as an 88GT however at the cost of a really really rough ride. I own an 88GT and an 85GT. The 88 rides like a luxury car in comparison to my 85GT. Fiero Racing List. Check out www.yahoogroups.com and search for Fiero, the list is dedicated to guys that Races Fiero's. The consensus on the 88 debate, is that the BEST Fiero suspension is an 84-87 front suspension, lowerd 1" and install all poly bushings, then install an 88 Rear suspension and drop it and install Poly. So start with an 85-87 V6 car, install an 88 rear suspension and you are good to go. (special note, the 84 front suspension was slightly different, so try and stay away from the 84 front stuff) Uhm, that is the short version of the post. ------------- Capt Fiero 88 Fiero GT 5spd V6 Eight Fifty Seven GT V8 5spd. |
Posted By: CFoss
Date Posted: 15 April 2008 at 2:26pm
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Freaking network error!!! Anyone else get that after writing a book?
Wiped my response out!
Thanks for the post David. I'll check out the Yahoo Groups for more info. I've read somewhere that lowering the 88 doesn't yeild positive results, so it's interesting. I'm deciding on this right now. I have an 86se (Rough but good drivetrain) and an 84 in good shape which I'm going to swap the drivetrain and an 88 rear into. Now maybe I have to swap the 86 front too? Or the 88 front? Hard to decide, because I don't really want to lower it. Probably the 88's are the way to go?
Chay ------------- 86 SE 3.4 |
Posted By: Capt Fiero
Date Posted: 15 April 2008 at 2:34pm
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Don't use the 84 Front suspension unless you absolutely have to. The 84 had something wrong with it. GM did a change to it in 85. You can install an 85-87 suspension on an 84 car to correct the issue. It was something to do with the turning radius and suspension travel. I am sorry I don't have details on what they changed. Oh the cables showed up. I am back in BC now and got the package. They look very cool. I spoke to Watts about them and he said there are COM Port to USB Adapters out there. So we are going to try and find some and test them out. The only laptop I have with a com port has all but 64mb of ram removed from it so it is really slow. You did mention you had the 84 that you were going to pull the engine and trans from. When you have it dropped, I would love to check it and see if it is a 3.32 or a 4.10. Heck if you are close enough I will come and help you pull it. ------------- Capt Fiero 88 Fiero GT 5spd V6 Eight Fifty Seven GT V8 5spd. |
Posted By: CFoss
Date Posted: 15 April 2008 at 2:59pm
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It's in Duncan and I't's coming out probably next week.
I have experience with the USB to com adapters...they are cheap and work pretty well.
The old computer would probably run winaldl fine though. I'd try it unless you want to port the data to some other computer it which case lan/usb jump drives are nice to have.
If there's an easy way to check the ratios? Would the VIN help? Chay ------------- 86 SE 3.4 |
Posted By: Capt Fiero
Date Posted: 15 April 2008 at 4:08pm
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It would be on the RPO sticker on the drivers fender under the hood. I will have to look up the RPO for the 3.32 ratio trans. However these cars are 20+ years old and its really hard to tell if the parts have been swapped out or not until you get the trans right out of the car. Once it is out of the car, you can put it into 4th gear and turn the input shaft by hand and count the rotations of the output. I have all the ratio's here. Its also listed on my trans website.
http://captfiero.com/transratios.htm ------------- Capt Fiero 88 Fiero GT 5spd V6 Eight Fifty Seven GT V8 5spd. |