New guy here, bringing another thirdgen to the mix Options

[Pablo]

Hello all,
I have been lurking for some time and wanted to introduce myself. I'm an aircraft mechanic living in so cal coming from the drag racing scene. Being originally from south florida, there was essentially no attraction to good handling for me since every road in basically the whole state of florida is straight and flat.
In the past 8 years of living in California I have seen what I can only say is the death of drag racing through track closures, police harassment, etc. This in addition to the magnificent twisties around here has built an itch for me to get into the road racing/ autox scene. It didn't help when a buddy of mine was able to regularly get me a ridiculous amount of free track time at a shall be un-named go kart track. Chasing faster lap times is extremely addicting. Couple this with going for canyon runs in his gutted E36 bmw, and I was hooked.

I previously owned an 89 Firebird from 97-04. It was basically set up for drag. I was very heavy into thirdgens for that time period. That car ended up meeting it's end when I moved on to an 86 T-type which I still own. (It's run as quick as a 7.0@95 mph, 1.54 60' in the 1/8th and should be substantially quicker when I get a working transmission under it).
Even after all these years I still missed my thirdgen, so I decided to go out and buy one. After putting out some feelers, I found a 91 Z28 LB9/T5 hardtop (rear drums (IMG:http://www.frrax.com/rrforum/style_emoticons/default/sad.gif) ) that was pretty rough. I managed to get it home with what felt like 75 hp. After repairing countless atrocities committed by previous owners I now have it running pretty well. Feels like stock with the "upgraded" 2 1/4" kink bent exhaust that some retard put on it. It's my daily driver now, knocked down almost 25 mpg last tank. Unfortunately it still looks like hell. I'll be painting it myself soon.

Anyway, plans for the car are to build it to either STX, STU, or ESP. I am still debating this. In the meantime here is what I have sitting on the shelf waiting for install; complete poly bushing set (will not do both lca ends in poly) MOOG 5664/5665 springs, AC delete heater box (already have the pulley installed), Koni Yellows (on backorder), lt1 ministarter, GTA crosslace wheels (will go with something else later), G.W. Tracklink (left over from the old car, still researching if the short arm is a good idea for what I am doing), 82-83 factory fiberglass z28 hood, hooker headers + 3" y pipe, T-top/vert door shim strikers.

I plan on cutting the springs half coil or so in the front which from what I understand will bump me into the low 800s spring rate wise. To help compensate for the roll center and camber curve issues this creates I'm looking into some taller ball joints (will post about this in the susp. forum). Rear springs will be cut as well. I'll probably start at 3/4 coil for those.
I would love to run a weight jack setup but I wanted to get my feet wet cheaply and quickly.

I'll probably look into some LCA RBs and a panhard relocation setup soon.

Right now I just want to get it to where I can go out and tear up some tires. As it sits, the shocks are so blown that I can induce violent wheel hop (on the front wheels!) with aggressive driving. So I'm taking it easy.

I'll also be applying some of my composites training to the car- I have some ideas (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif)

And yes, from what I've read, some of these mods are probably not technically legal in stx/stu but I think I can fly under the radar locally (don't snitch on me). I would mostly like to be in a challenging class. In judging from local results for ESP, there are basically no competitors in that class or F stock. STX isn't very good either but a lot better. STU has a ton of competitors.
I thrive on competition, I'd rather be dead last in STU with a bunch of other drivers than first in an ESP class with only one or two other drivers.

Anyway, sorry for the book. Check my post on the susp. forum for my ball joint q.
Here are some picts of the cars. The camaro looks slightly nicer now that I've touched up the bare metal the previous owner left from his "paint prep" job.


Buick:
(IMG:http://i53.photobucket.com/albums/g71/Chewbaccathedog/Barona/_MG_7630.jpg)
(IMG:http://i53.photobucket.com/albums/g71/Chewbaccathedog/eng-1.jpg)


Camaro
(IMG:http://i53.photobucket.com/albums/g71/Chewbaccathedog/IMG_0710.jpg)

[CrashTestDummy]

Welcome! Nice rides, both of them. There's lots to glean from this forum, I'd start with the Chassis and suspension sticky in the Suspension section, with a copy of the SCCA Solo rulebook open for reference.

Personally, I would not cut the springs, as it looks like the car is sitting about right now. You want the front and rear lower control arms to sit as close to level as possible. Additionally, I would highly recommend subframe connectors, if the rules allow. I know they are allowed in ESP, but not sure of the Street Touring class.

Other than that, put some decent tires on the GTA wheels and go get about a year's worth of driving experience before spending a lot on the car other than normal maintenance.

[CMC #37]

Welcome Pablo! After doing some research on my '91 Formula WS6 car, which also had drums, there was some kind of "shortage" on the disc brake rears. It is not hard to buy some PBR disc brakes new, so I would either do that or find another rear end that comes with them. Here's the '91 Formula here:

http://www.frrax.com/rrforum/index.php?sho...&hl=Formula

I decided to do a "resto-mod." (IMG:http://www.frrax.com/rrforum/style_emoticons/default/wink.gif) Project is still at Blaine Fab awaiting his magic hands! (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif)

[rhit_rs]

Welcome to the forum! Great intro!

I'm no longer in a third gen, but I do miss how well these cars handle when you throw big sway bars on them.

If you want to be competitive, you're going to have a hard time in either STX or STU if there's any decently prepped, well driven cars in the region you want to run with. STX is tough for f-bodies because you're capped at a 265mm wide tire and you'll definitely be at a power to weight disadvantage compared to the top cars in the class (non-M e36 bmws, RX8, WRX, etc) because engine modifications are extremely limited (before intake manifold, chip tune, and exhaust mods only). STU will let you run a wider tire (unlimited, I think), but you'll be even more down on power compared to the evo's, sti's, m3's and the like. Obviously the street tire rule doesn't do high torque rwd cars any favors either.

ESP on the other hand, you can actually be competitive nationally with a third gen (ex: Mark Madarash in his 3rd gen trans-am). You can swap engines from any 82-92 camaro (read the update/backdate section of the rules), letting you swap to an L98. Sub-frame connectors are now legal (not in ST*), and you have more flexibility in what you can do to the suspension as well (I don't think panhard rod relocation is legal in ST*). You can also swap to rear disc brakes (can't in ST*). Basically, it lets you fix a bunch of the third gen's problems that he ST* rules don't let you address. Oh, and you can run massive race tires, as wide as you want (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif) . If you don't want to pop for $$ race rims and tires right away, I'd work on getting the suspension stuff sorted out and run on a decent set of street tires in ESP. You can still compare your raw times to STX or STU cars, but you aren't putting their panties in a jumble by running in their class illegally. Once you get a bit of seat time and brush up on your "wheel man" skills, shelling out the cash for wide, grippy race tires and rims will pay huge dividends in your times.

Oh, and if you want to go crazy...there's always CP!

I think cutting a new set of moog springs is a good way to get a stiffer spring and lower ride height for cheap. Obviously the stock springs are sagging a bit at this point. I did a bunch of searching for factory rear springs that I could cut down a coil and get the right ride height and a little stiffer than stock rate (like the 5665 for the front), but didn't have much luck. I have a spread sheet with a bunch of moog springs compiled. If you want to see it, send me a PM.

[CMC #37]

You can also swap to rear disc brakes (can't in ST*).

Hmmm? Rear discs are stock in 3rd gens.

[roostmeyer]

Actually STU allows brake swaps, ST and STS don't, not sure about STX, unfortuneately you can't cut stuff off to install the common front brake kits or to put discs on drum rear. I've always thought an STU build would be fun with barebones f-body, but if the e36/e46 M3's can't get it done with the same amount of power as us, IRS and lighter weight, I don't think a f-body can be anything more than regionally competitive.

265/45r16 Kumho XS's on GTA wheels would get you started in STX on the cheap if you have a 305 car.

This post has been edited by roostmeyer: Apr 9 2010, 09:24 PM

[StanIROCZ]

This in addition to the magnificent twisties around here has built an itch for me to get into the road racing/ autox scene.

You've came to the right place my friend. (IMG:http://www.frrax.com/rrforum/style_emoticons/default/2thumbs.gif)

I'll also be applying some of my composites training to the car- I have some ideas (IMG:http://www.frrax.com/rrforum/style_emoticons/default/smile.gif)

SWEET! Let us know how that goes.

Sound like your on the right track with your mod list.

[Pablo]

Thanks for the warm welcome everyone,

Yes the stock springs in the car are severely sagging. Actually I would not be surprised if someone cut them at some point, the car is very low. The only indication that they are probably completely stock is that the rest of the car is completely stock except for a flowmaster muffler.
The moog springs should probably raise my ride height even when cut I reckon.

CMC 37, thats a very nice Formula you have there. Yes I've seen the same information concerning the rear drums, I too have heard about some shortage at the end of the thirdgen run. Its kind of funny because I think there was a shortage in the early years too which led to a "ws7" option which was just ws6 with rear drums.

rhit, I may have seen your chart of moog springs, I did a lot of searching before I finally settled on the 5664s on the front. For the rear I had the same issue as you, it seemed to me that I could only find one of two springs for the rear, one of which were the "cargo coils" that I did not want.
I wouldn't mind seeing that chart of yours anyway though in case I haven't seen it.

I see what you are saying about running in ESP vs the ST classes. One of the things that attracted me to the ST classes is the tire rules. Getting a set of wheels and tires for ESP would cost a pretty penny. Though I can see how running a third in those classes would be rough. I think the fact that thirdgens have done so well in ESP also kind of takes some fun out of it for me personally as I like to be an underdog. I'll see what I end up with mod wise and go from there. I'm waiting till sometime in may for these dang konis to come in off backorder before I tear into the car.
In the meantime I just came back from an AutoX event today just to spectate. It just has me even more amped up.

Roostmeyer
I didn't think that anything wider than a 245 would really fit right on the 8" wheels so I'm kind of surprised at the suggestion. Do the 265/45s really fit on there well enough to run on? I would have thought I'd need a 9" wheel instead. If the gta wheels really can accept a 265 then that's probably the route I will go. That's very a interesting suggestion, I'm looking into those tires now.


Stan, about the composites, I'd have to look more closely at the rules to see what is allowed. Even so, I'm surprised I haven't heard of people using them for chassis stiffening at all. It would be very easy to stiffen up parts of the car with very little weight penalty. In the meantime I think the first project that I'll try is reproducing the AC delete heater box in either CF or fiberglass just for kicks. It might be a little while before I get around to that though

Thanks again for the welcome!
Pablo

[ReEntryRacer]

Hello Pablo!

Great to see another 3rd Genner. I've been racing for 10 years, first in a '89 LB9T5 IROC, and for the last 5 years in a '82 TA built to SCCA GT1 rules.
I also enjoy the underdog role up here and truly enjoy it when I win. If I can assist with anything, just ask.

http://thetwobells.shawwebspace.ca/pages/v...portscar_champ/

This post has been edited by ReEntryRacer: Apr 12 2010, 06:27 AM

[rhit_rs]

You can also swap to rear disc brakes (can't in ST*).

Hmmm? Rear discs are stock in 3rd gens.

I think so. The later Z28's (89-92?) have the same rear brakes as the LT1 cars (11" PBR).

[rhit_rs]

rhit, I may have seen your chart of moog springs, I did a lot of searching before I finally settled on the 5664s on the front. For the rear I had the same issue as you, it seemed to me that I could only find one of two springs for the rear, one of which were the "cargo coils" that I did not want.
I wouldn't mind seeing that chart of yours anyway though in case I haven't seen it.

I see what you are saying about running in ESP vs the ST classes. One of the things that attracted me to the ST classes is the tire rules. Getting a set of wheels and tires for ESP would cost a pretty penny. Though I can see how running a third in those classes would be rough. I think the fact that thirdgens have done so well in ESP also kind of takes some fun out of it for me personally as I like to be an underdog. I'll see what I end up with mod wise and go from there. I'm waiting till sometime in may for these dang konis to come in off backorder before I tear into the car.
In the meantime I just came back from an AutoX event today just to spectate. It just has me even more amped up.

Pablo

I'll try to dig up the chart and post it on here in some fashion. I may have to email it if it won't let me upload an excel file...

Street tires act as an equalizer and nullify the torque advantage of the V8. Light weight is the key in the ST* classes...just look at how fast the ST and STS cars can be with very little power and on skinny 205mm tires! The 265mm Kumho XS would definitely be a good STX tire for 3rd gen. It has gobs of grip but sucks in the rain from what I've read. And lets face it, if the course is wet, the WRX's are going to dominate STX.

Another thought, and you'd have to check with the regional rules, is to run in a street tire index class. That would let you run on street tires against other cars with street tires and use the rules (and subsequent index) of ESP. I think some of the California regions do this to give everyone on street tires a place to be competitive. Just a thought.

With regards to being an underdog, you see so few 3rd gens autocrossing, that very few of your competitors will take you seriously. If you can put down some fast times, you'll definitely turn some heads!

[trackbird]

Josh,

Send me the spreadsheet and I can upload it to the board (assuming it's not over the file limit).

[Pablo]

So what is the verdict concerning the Kumho 265/45 xs tires? Will they really fit an 8" wheel well enough to autoX with? Their specs state the minimum size is an 8.5" wheel. What's going to happen if I use them on an 8" wheel?

[trackbird]

You can also swap to rear disc brakes (can't in ST*).

Hmmm? Rear discs are stock in 3rd gens.

I think so. The later Z28's (89-92?) have the same rear brakes as the LT1 cars (11" PBR).

I don't believe that's exactly true. Jon A found a wilwood aluminum hat (2 piece rotor) setup for his LT1. Upon asking if that was a fot for a 3rd gen, I was advised that the offset of the rotors is somewhat different. I don't know that the brackets do (or don't) swap but the rotors very well may be different part numbers between the vehicles (and I suspect they are).

[roostmeyer]

So what is the verdict concerning the Kumho 265/45 xs tires? Will they really fit an 8" wheel well enough to autoX with? Their specs state the minimum size is an 8.5" wheel. What's going to happen if I use them on an 8" wheel?

I would stick real close to the recommended rim widths once you get to a lower profile tire, but for a 265/45 i think they will still be plenty safe on a 8" wheel. It'll probably give up a little bit of tread width due to the pinch and may cause the tire to react slower. For a 16" performance tire I think you'll still be better off with the XS than a crap tire in the right size. I'm guessing you could pick up some 17x9's and have a lot more options for street tires, but the only wheel options I can think of would be pretty heavy.

Kevin, this is quick and dirty spreadsheet I made for doing spring rate/height calcs. For whatever reason it isn't quite right, but it should be able to get somebody in the ballpark on spring rates. Its got all the OEM springs in there as well.

https://spreadsheets.google.com/ccc?key=0Am...1KMGc&hl=en

This post has been edited by roostmeyer: Apr 15 2010, 02:58 PM

[Pablo]

So what is the verdict concerning the Kumho 265/45 xs tires? Will they really fit an 8" wheel well enough to autoX with? Their specs state the minimum size is an 8.5" wheel. What's going to happen if I use them on an 8" wheel?

I would stick real close to the recommended rim widths once you get to a lower profile tire, but for a 265/45 i think they will still be plenty safe on a 8" wheel. It'll probably give up a little bit of tread width due to the pinch and may cause the tire to react slower. For a 16" performance tire I think you'll still be better off with the XS than a crap tire in the right size. I'm guessing you could pick up some 17x9's and have a lot more options for street tires, but the only wheel options I can think of would be pretty heavy.

Kevin, this is quick and dirty spreadsheet I made for doing spring rate/height calcs. For whatever reason it isn't quite right, but it should be able to get somebody in the ballpark on spring rates. Its got all the OEM springs in there as well.

https://spreadsheets.google.com/ccc?key=0Am...1KMGc&hl=en

Thanks for the reply. I also did some searches online and it seems like plenty of people are running tires a little wider than spec for various rim sizes. So I think I will be ok

I was looking at your spreadsheet, pretty cool info on there. One thing that seems like a mistake is that the 5664 and 5662 springs seem to be reversed in their spring rate. The 5664 has a larger wire diameter and is listed at a lower spring rate. Doesn't seem right. I had read other posts on TGO speaking of this apparent discrepancy on the moog spring rate listings. Do you think they screwed up? It would seem so to me, the 5664 is the spec spring for convertables. I wouldn't figure they would use a lighter spring on an even heavier car.

[roostmeyer]

Thanks for the reply. I also did some searches online and it seems like plenty of people are running tires a little wider than spec for various rim sizes. So I think I will be ok

I was looking at your spreadsheet, pretty cool info on there. One thing that seems like a mistake is that the 5664 and 5662 springs seem to be reversed in their spring rate. The 5664 has a larger wire diameter and is listed at a lower spring rate. Doesn't seem right. I had read other posts on TGO speaking of this apparent discrepancy on the moog spring rate listings. Do you think they screwed up? It would seem so to me, the 5664 is the spec spring for convertables. I wouldn't figure they would use a lighter spring on an even heavier car.

Most likely the 5664 has more active coils for it to get a lower spring rate with a larger diameter coil. If you mess with the spreadsheet some you can see the differences it makes with cutting just 1/2 a coil off. It would seem to be smarter to just add another 1/4 of a coil to a spring with .750 wire to make a slightly softer spring but they may have had some other design criteria that we're not seeing now 20 years later that justified the larger coil size. If you've got good photos of the 5664 and the 5662 I can make a guestimate on the number of active coils and add those to the spreadsheet to see what the spring rate should be analytically.

[Pablo]

Most likely the 5664 has more active coils for it to get a lower spring rate with a larger diameter coil. If you mess with the spreadsheet some you can see the differences it makes with cutting just 1/2 a coil off. It would seem to be smarter to just add another 1/4 of a coil to a spring with .750 wire to make a slightly softer spring but they may have had some other design criteria that we're not seeing now 20 years later that justified the larger coil size. If you've got good photos of the 5664 and the 5662 I can make a guestimate on the number of active coils and add those to the spreadsheet to see what the spring rate should be analytically.

I have 5664s new in the box sitting at home. I can upload pics of them later today.

[Pablo]

Ok got the pics loaded (a little later than I had hoped)

Here are the 5664s, I measured it to just past .76 on wire diameter, about .762
(IMG:http://i53.photobucket.com/albums/g71/Chewbaccathedog/IMG_0771.jpg)


5665s:
(IMG:http://i53.photobucket.com/albums/g71/Chewbaccathedog/IMG_0773.jpg)

[Pablo]

Thought I would post an update on the car

It's come a long way since I first posted. I got a hold of some 17x11 and 17x12 CCWs with 315 hoosier R6s up front and 335 Hoosier R6s on the back. Had to do a minitub and throw in a 6 point cage. I've done a lot of little things besides that like spherical bearing strut mounts, phb relocation, al lcas, phb, new steering wheel, 'glass hood etc etc.. Even these picts are not up to date.
Right now im in the process of fixing the hole in the trunk, adding a dana 44, ultrashield rally sport seat, harnesses, battery relocation, 3" exhaust, headers, etc.

I've decided to go C prepared. It should be interesting at the autoX down here in so cal. I think they will have a heart attack when they see a thirdgen camaro tearing it up. I certainly had jaws drop at a local time attack and that was just on 275 victoracers, open diff, and before I gutted it/caged it, etc.

anyway here are the picts a lot of them were the "in progress" pictures. Most of this work is done now.

(IMG:http://i53.photobucket.com/albums/g71/Chewbaccathedog/IMG_0925.jpg)
(IMG:http://i53.photobucket.com/albums/g71/Chewbaccathedog/IMG_0929.jpg)
(IMG:http://i53.photobucket.com/albums/g71/Chewbaccathedog/IMG_0923.jpg)
(IMG:http://i53.photobucket.com/albums/g71/Chewbaccathedog/mailgooglecom.jpg)
(IMG:http://i53.photobucket.com/albums/g71/Chewbaccathedog/IMG_20100926_182429.jpg)
(IMG:http://i53.photobucket.com/albums/g71/Chewbaccathedog/IMG_1021.jpg)
(IMG:http://i53.photobucket.com/albums/g71/Chewbaccathedog/IMG_1022.jpg)


I don't have any good picts of the cage but you can see a little through the windows on the last picts. I'll get those up when I get the harness bar in etc.

This post has been edited by Pablo: Dec 6 2010, 06:24 AM