What is the best C4 year and suspension for autocross racing?
09-13-2009, 07:27 PM
#21
Le Mans Master
Member Since: Feb 1999
Location: Hawaii
Posts: 8,522
Likes: 0
Received 3 Likes
on
3 Posts
St. Jude Donor '03 & '05
Another thing was tire sizes, 89-92 all had 275/40-17's( not sure of 87 and older), 93 they changed to 255 up front with 285 rearm unless you had the ZO7 type suspension as the codes changed, ZO7, Z51 etc etc.
Of course the Grand Sport of 96, coupe, had 275 front with 315 rear.
Of course the Grand Sport of 96, coupe, had 275 front with 315 rear.
09-13-2009, 08:08 PM
#22
Melting Slicks
But aggressive does not equate to best...
If you are racing on a pool-table smooth track, it is a GREAT suspension. But it is SO stiff that any ripples in the pavement make it bounce like mad. Stiff is not always the best.
Also, the engines (and the 4+3 transmissions) sucked in the '84's (IMO).
If you are racing on a pool-table smooth track, it is a GREAT suspension. But it is SO stiff that any ripples in the pavement make it bounce like mad. Stiff is not always the best.
Also, the engines (and the 4+3 transmissions) sucked in the '84's (IMO).
09-13-2009, 10:29 PM
#23
I have an 89 "true" Z51 car (no FX3) that I autocrossed and tracked for years. Hard to beat the combo.
However, keep in mind that in 89 all Z51's were not created equally. The cars with FX3 got the big brakes and auxiliary coolers but they had Z52 base rate springs, stab bars, and bushings. This was done for a couple of reasons. The first was to make sure they could tune the car so that it rode better than a base car when the shocks were set to comfort. More importantly, there were some significant doubts as to whether Bilstein could keep up with the projected volumes in 89 so they restricted the option to require a manual and the big brakes to help keep the FX3 volumes down. There were only 651 "true" Z51's built in '89, so it may be tough to find one.
The 91 ZO7 had all the true Z51 parts (springs, bars, etc) but added FX3 and the 26mm rear stab bar from the ZR1 (89 true Z51's had a 24mm bar).
However, keep in mind that in 89 all Z51's were not created equally. The cars with FX3 got the big brakes and auxiliary coolers but they had Z52 base rate springs, stab bars, and bushings. This was done for a couple of reasons. The first was to make sure they could tune the car so that it rode better than a base car when the shocks were set to comfort. More importantly, there were some significant doubts as to whether Bilstein could keep up with the projected volumes in 89 so they restricted the option to require a manual and the big brakes to help keep the FX3 volumes down. There were only 651 "true" Z51's built in '89, so it may be tough to find one.
The 91 ZO7 had all the true Z51 parts (springs, bars, etc) but added FX3 and the 26mm rear stab bar from the ZR1 (89 true Z51's had a 24mm bar).
09-14-2009, 10:27 AM
#24
Advanced
Thread Starter
Member Since: Feb 2008
Location: Little Rock Arkansas
Posts: 97
Likes: 0
Received 0 Likes
on
0 Posts
Thank you all for the very valuable input. Sounds like it may take a lot of salvage yard mixing and matching to put together the best combo as it seems “the right stuff” combinations happened in limited quantities and in different years.
There is no way, I would be interred in A Stock class with my planned car. And my project goals are to build the best handling C4 possible on a very limited budget. I’ll get the Bilstien shocks for autocross that’s for sure, and plan to rebuild the car with polyurethane bushings and install a 6, 8 or 10 point cage. (still will have full interior, but may eventually upgrade to road racing style seats and harnesses since the economy ones are less expensive than re- upholstering the stock seats). However, it’s NOT going to be a “Butcher job” or have the look of a race-only car. It will keep all stock dash functions and the mods will be kept clean enough that it can go to some local car shows. I do plan on running 17 X 11 rear wheels with 315/35s and I may put the 17 X 11s under the front as well, but have not yet decided if stretching the 275s or mounting the 315s would be best. (I’m open for opinions on that one).
I plan to get and install THE thickest aftermarket front sway bar possible and use whatever diameter rear bar will best balance that after my engine weight & placement, and wheel/tire combo is in place (I suspect that the thickest stock rear sway bar would be about right – as a guess, but I don’t want too stiff of a rear bar if the rear springs are too stiff – again, that is a guess.
For this suspension thread, what I will mention about the engine is that it is 35 pounds heavier than the 350, but will sit 1.5” to 2” rearward of the stock location. I am willing to relocate the battery or loose the AC to compensate the weight if needed, however slightly stiffer springs (like maybe the 84 front springs- maybe???) Anyway, I do understand the softer spring to stiffer shock advantage over stiffer springs when it comes to imperfections in the track. But I must also consider the extra weight of the engine and whatever weight the padded and covered roll cage will add. I’m hoping the rearward positioning of the engine and the weight of the cage will maintain the front to rear balance.
I’ll be using an automatic with a Dana 44 rear end and 3.07 gears because of the torque building nature of the engine 550 lbs. torque @ 3000 RPMs and in the autocross runs will be using first and second gear up to about 4600 RPMs. I may only see third in the slalom, and that would be for a just few seconds. Building a clutch that would survive this engine and paying for a strong enough manual shifting tranny limits me to an automatic, but since my engine will red line at 5,000 and have an optimum shift point at about 4500 RPMs, I don’t think a manual would be that much of an advantage.
Whatever car I get will eventually have the 13” brakes up front, and I have even thought about swapping in 13 discs on the rear (may have to run Eldorado rear calipers to open up wide enough for the vented discs.) And then using an adjustable proportion valve to balance the braking.
I don’t know if solid body mounts are available, but I have also thought about using them for chassis stiffening. The cage is mainly to keep the chassis firm for cornering to keep the engine from torquing the body to the point of loosing the glass top.
Since I plan to run a modified version of the Car’s TPI or swap one in, I have been told I would need to avoid 90 up cars due to their electronics. I’m not at all opposed to swapping in suspension components from a 90 up car, however.
I would not want to lower the front of the car if that would interfere with suspension geometry for cornering, but would at least lower the rear one inch for better weight transfer under acceleration as I will need all of the help I can get to hook the tires coming out of the turns and unleashing the 350 lbs. of torque that will hit them at 1500 RPMs and quickly build to the 500 + range.
It looks like 86 and 88/89 are the best starting points, however there is a debate about early vs. late suspension designs. One thing I have thought about (if there is a fix to the camber loss of the later suspension design, is running a later front suspension with an earlier rear suspension and having all four wheels of the later suspension offset. This would allow the 11 rear wheels to have a narrower center of track width than the front, and cars with a narrower rear track have a cornering advantage over cars with a wider rear track.
Still so many variables to consider, I just wanted to know what the best starting point would be; it may be that my willingness to mix and match may mean, just buy any C4 and start from there, but I’d still like to have at least part of my final product under the car that I buy to save on the expenses and to have the ability to drive and race as I experiment and upgrade (as budget allows….)
The challenge of taking a C4 and trying to improve on its already good design will be half of the fun of ownership and a very enjoyable hobby.
Any more thoughts now that I have really stirred up the waters with this incredibly long reply - LOL
There is no way, I would be interred in A Stock class with my planned car. And my project goals are to build the best handling C4 possible on a very limited budget. I’ll get the Bilstien shocks for autocross that’s for sure, and plan to rebuild the car with polyurethane bushings and install a 6, 8 or 10 point cage. (still will have full interior, but may eventually upgrade to road racing style seats and harnesses since the economy ones are less expensive than re- upholstering the stock seats). However, it’s NOT going to be a “Butcher job” or have the look of a race-only car. It will keep all stock dash functions and the mods will be kept clean enough that it can go to some local car shows. I do plan on running 17 X 11 rear wheels with 315/35s and I may put the 17 X 11s under the front as well, but have not yet decided if stretching the 275s or mounting the 315s would be best. (I’m open for opinions on that one).
I plan to get and install THE thickest aftermarket front sway bar possible and use whatever diameter rear bar will best balance that after my engine weight & placement, and wheel/tire combo is in place (I suspect that the thickest stock rear sway bar would be about right – as a guess, but I don’t want too stiff of a rear bar if the rear springs are too stiff – again, that is a guess.
For this suspension thread, what I will mention about the engine is that it is 35 pounds heavier than the 350, but will sit 1.5” to 2” rearward of the stock location. I am willing to relocate the battery or loose the AC to compensate the weight if needed, however slightly stiffer springs (like maybe the 84 front springs- maybe???) Anyway, I do understand the softer spring to stiffer shock advantage over stiffer springs when it comes to imperfections in the track. But I must also consider the extra weight of the engine and whatever weight the padded and covered roll cage will add. I’m hoping the rearward positioning of the engine and the weight of the cage will maintain the front to rear balance.
I’ll be using an automatic with a Dana 44 rear end and 3.07 gears because of the torque building nature of the engine 550 lbs. torque @ 3000 RPMs and in the autocross runs will be using first and second gear up to about 4600 RPMs. I may only see third in the slalom, and that would be for a just few seconds. Building a clutch that would survive this engine and paying for a strong enough manual shifting tranny limits me to an automatic, but since my engine will red line at 5,000 and have an optimum shift point at about 4500 RPMs, I don’t think a manual would be that much of an advantage.
Whatever car I get will eventually have the 13” brakes up front, and I have even thought about swapping in 13 discs on the rear (may have to run Eldorado rear calipers to open up wide enough for the vented discs.) And then using an adjustable proportion valve to balance the braking.
I don’t know if solid body mounts are available, but I have also thought about using them for chassis stiffening. The cage is mainly to keep the chassis firm for cornering to keep the engine from torquing the body to the point of loosing the glass top.
Since I plan to run a modified version of the Car’s TPI or swap one in, I have been told I would need to avoid 90 up cars due to their electronics. I’m not at all opposed to swapping in suspension components from a 90 up car, however.
I would not want to lower the front of the car if that would interfere with suspension geometry for cornering, but would at least lower the rear one inch for better weight transfer under acceleration as I will need all of the help I can get to hook the tires coming out of the turns and unleashing the 350 lbs. of torque that will hit them at 1500 RPMs and quickly build to the 500 + range.
It looks like 86 and 88/89 are the best starting points, however there is a debate about early vs. late suspension designs. One thing I have thought about (if there is a fix to the camber loss of the later suspension design, is running a later front suspension with an earlier rear suspension and having all four wheels of the later suspension offset. This would allow the 11 rear wheels to have a narrower center of track width than the front, and cars with a narrower rear track have a cornering advantage over cars with a wider rear track.
Still so many variables to consider, I just wanted to know what the best starting point would be; it may be that my willingness to mix and match may mean, just buy any C4 and start from there, but I’d still like to have at least part of my final product under the car that I buy to save on the expenses and to have the ability to drive and race as I experiment and upgrade (as budget allows….)
The challenge of taking a C4 and trying to improve on its already good design will be half of the fun of ownership and a very enjoyable hobby.
Any more thoughts now that I have really stirred up the waters with this incredibly long reply - LOL
Last edited by CadVetteStang; 09-14-2009 at 10:34 AM.
09-14-2009, 11:55 AM
#25
Safety Car
You can get what you want (HP and torque) from an L98 with a modified TPI...no special electronics needed. I'm pushing 400 HP/500 lb.ft. with a 355 L98. A custom PROM is all you need with a stock computer to make it work. Less chances of something going wrong with a harness interface...
You really want a later model car. The problems with early EFI is speed-density vs. MAP. The speed-density limits you to a certain airflow through the sensor, and with MAP you aren't. They (GM) had good reasons to go to it...
Wheels/tires and suspension geometry are tricky things to get right. I'm not sure doing a mix & match will be good for you. I did go with all the Rippie mods (camber & trailing link brackets and heim trailing links/camber rods). I run Goodyear Eagles on 18" rims to race with, they are 12" wide on all 4 corners. Can't fit anything more than that without going beyond the fender lip. I have my car lowered as far as it would go with the stock Z07 front spring (shaved the rubber pad off and inserted a 1/8" spacer on top). Then, I lowered the rear to within 1/4" of the front (measured at the top of the wheel arch opening).
CCW Wheels is where I got mine made, and John knows what my offsets are...he can hook you up with a nice set of 3-piece forged wheels for pretty cheap (mine were $1800/set 4 or 5 years ago).
Sounds like you are in for a multi-year project. I've been there before
.
I have my eye on building a race car using a wrecked ZR1 to give me more room for tires on the rear. I have been assembling the goodies to build a 427 SBC using a Bowtie racing block putting out > 700 HP and 750 lb/ft. This poor car doesn't have room to get enough tire under the back to keep it all planted. I will do it the same as you...full cage (w/swing-out door bars), full interior (with A/C) and show others it can be done (and be able to cruise in comfort here in Texas in the summer).
There is certainly a wealth of knowledge here. Ask questions and you'll get hundreds of answers and ideas. If you can think of it, someone in here has already done it and can help you out (or steer you in another direction because of their experience).
Good luck on the build...take lots of progress pictures and document it so others can learn as well.
Joe Raymond
Longhorn Corvette Club
'91 Z07 White/Grey 6-speed
"91 Z07" TX Vanity Plate
Engine:
355 ci L98 with 52MM Throttle-Body, Ported Plenum, ASM Runners, Accel siamese-ported base plate, 24# injectors, 1.6 rollers, 218 CFM CNC-ported stock heads, Corvette Challenge cheater cam, 10.6:1 compression, Canton Road-Race Oil Pan, Ron Davis Aluminum Radiator w/Integrated oil cooler, 180 Deg. Thermostat, TPIS Jet-Hot coated headers, Formato custom chip
Drivetrain:
Single-mass flywheel, CenterForce Dual-Friction clutch/pressure plate, Hurst billet shifter, Poly bushings, Mid-America lowering kit, 295/30YF18 BFG k/d's on OZ 18"x10" Monte Carlo Rims, Doug Rippie suspension modifications, Bilstein custom-valved FX3 shocks, GM DuraStop "Performance" Drilled/Slotted rotors & GS calipers
Exhaust:
3" Random Tech "bullet" cats, Corsa LT1 dual exhaust
Dyno pull:
326.4 HP/399.3 lb/ft at wheels
397.56 HP & 487.8 lb/ft at flywheel
You really want a later model car. The problems with early EFI is speed-density vs. MAP. The speed-density limits you to a certain airflow through the sensor, and with MAP you aren't. They (GM) had good reasons to go to it...
Wheels/tires and suspension geometry are tricky things to get right. I'm not sure doing a mix & match will be good for you. I did go with all the Rippie mods (camber & trailing link brackets and heim trailing links/camber rods). I run Goodyear Eagles on 18" rims to race with, they are 12" wide on all 4 corners. Can't fit anything more than that without going beyond the fender lip. I have my car lowered as far as it would go with the stock Z07 front spring (shaved the rubber pad off and inserted a 1/8" spacer on top). Then, I lowered the rear to within 1/4" of the front (measured at the top of the wheel arch opening).
CCW Wheels is where I got mine made, and John knows what my offsets are...he can hook you up with a nice set of 3-piece forged wheels for pretty cheap (mine were $1800/set 4 or 5 years ago).
Sounds like you are in for a multi-year project. I've been there before
.I have my eye on building a race car using a wrecked ZR1 to give me more room for tires on the rear. I have been assembling the goodies to build a 427 SBC using a Bowtie racing block putting out > 700 HP and 750 lb/ft. This poor car doesn't have room to get enough tire under the back to keep it all planted. I will do it the same as you...full cage (w/swing-out door bars), full interior (with A/C) and show others it can be done (and be able to cruise in comfort here in Texas in the summer).
There is certainly a wealth of knowledge here. Ask questions and you'll get hundreds of answers and ideas. If you can think of it, someone in here has already done it and can help you out (or steer you in another direction because of their experience).
Good luck on the build...take lots of progress pictures and document it so others can learn as well.
Joe Raymond
Longhorn Corvette Club
'91 Z07 White/Grey 6-speed
"91 Z07" TX Vanity Plate
Engine:
355 ci L98 with 52MM Throttle-Body, Ported Plenum, ASM Runners, Accel siamese-ported base plate, 24# injectors, 1.6 rollers, 218 CFM CNC-ported stock heads, Corvette Challenge cheater cam, 10.6:1 compression, Canton Road-Race Oil Pan, Ron Davis Aluminum Radiator w/Integrated oil cooler, 180 Deg. Thermostat, TPIS Jet-Hot coated headers, Formato custom chip
Drivetrain:
Single-mass flywheel, CenterForce Dual-Friction clutch/pressure plate, Hurst billet shifter, Poly bushings, Mid-America lowering kit, 295/30YF18 BFG k/d's on OZ 18"x10" Monte Carlo Rims, Doug Rippie suspension modifications, Bilstein custom-valved FX3 shocks, GM DuraStop "Performance" Drilled/Slotted rotors & GS calipers
Exhaust:
3" Random Tech "bullet" cats, Corsa LT1 dual exhaust
Dyno pull:
326.4 HP/399.3 lb/ft at wheels
397.56 HP & 487.8 lb/ft at flywheel
Last edited by 1991Z07; 09-14-2009 at 12:01 PM.
09-14-2009, 11:58 AM
#26
Team Owner
Member Since: Mar 2001
Location: Boston, Dallas, Detroit, SoCal, back to Boston MA
Posts: 30,638
Received 239 Likes
on
167 Posts
Where's the OP going to race this?
(FYI he's dropping a 500ci Caddy into it)
The engine swap puts you soundly into SSM (Super Street Mod) and in that car just get a car since you'll be upgrading all the suspension pieces anyways.
(FYI he's dropping a 500ci Caddy into it)
The engine swap puts you soundly into SSM (Super Street Mod) and in that car just get a car since you'll be upgrading all the suspension pieces anyways.
09-14-2009, 02:19 PM
#28
Advanced
Thread Starter
Member Since: Feb 2008
Location: Little Rock Arkansas
Posts: 97
Likes: 0
Received 0 Likes
on
0 Posts
A basically stock 500, will be totally streetable; my 4860 lb. 70 Eldorado could handle 20 MPH stop and go traffic jambs in the summer with no issues. Fuel economy should be about 25 MPGs interstate if I use the MPG cam or about 22 MPG with the RV cam which is probably what I will start with. After I get the Dana 44 built up and the Tranny the way I want it, I can always go one step further on cam grinds and do some more porting - keep streetability and see 600 lbs. torque at less than 3600 RPMs. But then interstate MPGs would drop to less than 20MPG and I want to keep it as a daily driver in the 22 or better MPG range at 75MPH with the 3.07 gears. For now I want the best compromise of power and MPGs so I am keeping the Caddy very close to stock.
09-14-2009, 02:23 PM
#29
Safety Car
) Averages over 10 tanks HWY/CITY around 16-18 MPG. Has torque for days and I usually just shift 1-3-5 when driving it around. Will smoke the tires at will before I got new BFG KD's on it, but will still break them loose through 3rd when giving it a heavy right footed start (1-2-3) and bark them going into 4th.Idles nice, just a slight lope to it to let you know it isn't completely stock. From the outside the engine looks completely stock, I just powder-coated the intake crinkle-black to make it look a little different.
It's a real nice "sleeper", has A/C and full interior...and can pass emissions here with flying colors. Has dual CATS, TPIS headers with AIR injectors, and a full LT1/LT4 Corsa stainless exhaust on it.
It was always fun showing up to an autocross and people looking in/under/around the car trying to figure out WHY it was an NCCC Group 3E car...everything you see from the outside was all 2E (except the Goodyear slicks on it). After the first run when I'd crack the pedal and they heard the thing bark, the crowd would REALLY gather then...
Small clip of it here:
Last edited by 1991Z07; 09-14-2009 at 02:37 PM.
09-14-2009, 03:06 PM
#30
Pro
Member Since: Jun 2008
Location: Calgary Alberta
Posts: 531
Likes: 0
Received 0 Likes
on
0 Posts
Z07 - Can't view the video through this server... will check it out soon.
Sounds like a great setup!
-What do you figure the conversion cost you?
-Do / have you had any concerns about the bottom end?
-If you were about to do it again, is there anything you'd do slightly differently?
-how' are the exhaust notes while cruising?
Sounds like a great setup!
-What do you figure the conversion cost you?
-Do / have you had any concerns about the bottom end?
-If you were about to do it again, is there anything you'd do slightly differently?
-how' are the exhaust notes while cruising?
09-14-2009, 03:27 PM
#31
Safety Car
Z07 - Can't view the video through this server... will check it out soon.
Sounds like a great setup!
-What do you figure the conversion cost you?
-Do / have you had any concerns about the bottom end?
-If you were about to do it again, is there anything you'd do slightly differently?
-how' are the exhaust notes while cruising?
Sounds like a great setup!
-What do you figure the conversion cost you?
-Do / have you had any concerns about the bottom end?
-If you were about to do it again, is there anything you'd do slightly differently?
-how' are the exhaust notes while cruising?
Exhaust was $1k (including bending new head-pipes out of stainless to meet up with the headers).
Bottom end is solid (now). I was stupid and tried to save a few bucks on the initial build and put the stock pan on it. When you have as much sticky rubber as I do, it only takes the wrong combination of moves to screw things up. Heavy brakes, hard right hander into a sweeper and I sucked air and killed a crank and 3 rods. On the rebuild we used a Canton Road Racing pan and never have that problem anymore. Also added (2) 1-quart Accusumps for added insurance.
Exhaust note is sweet. The Corsa system seems to be a "love it or hate it" system in here. I LOVE being able to talk and not yell while cruising. No drone anywhere. Crack the throttle and it roars. That's what I like. I lived with a Flowmaster system on the car for 4 or 5 years and learned to HATE it...those of you who like it...wait a while, you'll change your mind like I did.
I think I spent somewhere around $1k total on all the suspension work done. Urethane bushings, Rippie brackets and links, Rebuilt FX3 shocks and new controller.
Edit: I also replaced the POS stock oil cooler with something that ACTUALLY works! I bought this from Canton and replaced the sandwich adapter. Bought a Ron Davis radiator with integrated oil cooler (same one for a auto-trans car) and had them put -8 fittings on it. Ran -8 braided hose to the radiator and voila! No more oil temp problems or water temp problems (says a lot for Texas summers). This stuff WORKS!
Last edited by 1991Z07; 09-14-2009 at 06:29 PM.
09-14-2009, 04:49 PM
#33
Burning Brakes
If you really want to dispel the "rumor and hearsay", do us all a favor and jack up your 91's front suspension. Count the number of turns from lock to lock and average the two sides; and then see what two letter code is imprinted on your rack.
09-14-2009, 04:54 PM
#34
Safety Car
As long as you don't get too aggressive, you can (most likely) get one built in the $4500-5000 range that will have every bit as much muscle as I have.
Heads will get a big chunk...good CNC heads will cost you in the $2k range. Forged pistons and crank will bite off another $1000-1500. The rest is machine work (squaring the decks, new 4-bolt splayed caps (mine was converted over) and an align-bore, boring the holes for the pistons, balance rotating assembly and blue-printing the assembly...and a slew of other details). Full roller-rockers, manifold, oil pan and oil pump round out the really big stuff.
Then I paid my machinist an extra $350 to assemble the block...came to me ready to drop back into the car. Intake sealed and RTV cured. Oil pan buttoned up and ready to go.
On some of this stuff, you can get it cheaper if you shop around and know what you want. Online shopping is one way, swap meets are another way and local sources (clubs, machine shop bulletin boards, etc.). I don't think I'd ever personally buy a used crank from anybody without a magnaflux test done to see if there are any hairline cracks. But I'm kinda funny about buying someone elses problems...which is why I got a new crank for mine...twice.
Find a good machinist and ask around about them. Mine does a crapload of boat motors, drag motors, drag-boat motors, off-road motors...been around here a long time and has a great reputation. I'll be sorry when he retires and I have to find a new one, but usually a GOOD machinist will know who else in their area is the next best choice to them...ask them...they'll tell you
Some can cut corners to save money and get lucky, but I went into it figuring about $5k...and if it wasn't for the fact that I had to spend money on a lawyer and getting a used motor (in parts) for $2k I'd have been right in the ball park.
I found my web site (again) and here are the numbers and costs associated with the rebuild:
Here is a basic list of parts we used for this engine:
130979 - J&E Pistons - $546.00
134-6003 - ARP Rod bolts - $45
234-5501 - ARP Main Studs - $112.00
134-3601 - ARP Head bolts - $92
JB2079 - Crower roller tappets - $197.95
73603 - Crower 1.6:1 ratio roller-rockers - $386.62
134-7101 - ARP Rocker studs - $45
74197 - Accel base plate - $425
20199-T9 - AS&M Runners - $394
X22212271-13 - Cam Dynamics Corvette Challenge cam designed for Tommy Morrison. Basically this is a ZZ9 cam with a "little" bit extra. Specs: 225/229@.050, duration 282/287, lobe separation 113 deg., lift w/1.6:1 rockers - .555/.556
With machine work and other "parts" the total came to $4771.70
Head CNC work would have added an additional $1600 to the total.
http://temp.corvetteforum.net/c4/joe90/index.shtml
Last edited by 1991Z07; 09-14-2009 at 08:10 PM.
09-14-2009, 05:26 PM
#36
Safety Car
Not that I doubt that you have the B1X code on your build sheet; however, saying that code means the quick steering ratio is a leap of faith. (What if all 91's have B1X and that's why it isn't on the console's build options list?)
If you really want to dispel the "rumor and hearsay", do us all a favor and jack up your 91's front suspension. Count the number of turns from lock to lock and average the two sides; and then see what two letter code is imprinted on your rack.
If you really want to dispel the "rumor and hearsay", do us all a favor and jack up your 91's front suspension. Count the number of turns from lock to lock and average the two sides; and then see what two letter code is imprinted on your rack.
And guess what is also on the Z51 cars...drum roll please....
...an Optional quick-ratio steering box (B1X)!
It isn't a leap of faith...but what they don't have in the parts catalog anymore is what the ACTUAL ratios are...
I'm not worried about dispelling myths...and getting a jack under the front crossmember on my car is impossible without getting it on some ramps. I have to pull onto ramps just to get my lift arms under the body. Next time I have it on the lift I'll let you know
There are a lot of things not on the door codes...HD radiator is one of them. Power steering cooler is another. BUT, they did have the oil cooler in there...strange, eh?
09-14-2009, 06:38 PM
#38
Safety Car
Glued to the road...maintains consistent camber through the entire travel of the tire. I didn't need to have something that changed camber (like the stock unit does). I run a pretty aggressive setup, so dialing in MORE camber at the top of the arc would have reduced the footprint on the ground. Rippies rear suspension changes made a real difference. Got the brackets and the rear knuckle mods done...what a difference!
I guess the best way to describe it is the car is more consistent. You can feel it at the edge of grip much better, and it won't just go away without advertising it like the stock setup can do. Best thing I did to the suspension, along with re-tuned shocks and urethane bushings.
(P.S. Buy the bushings from Rippie. I priced them out and they beat everyone else hands down.)
Last edited by 1991Z07; 09-14-2009 at 06:41 PM.
09-14-2009, 07:05 PM
#39
Pro
Member Since: Apr 2008
Location: middle of Illinois
Posts: 542
Likes: 0
Received 0 Likes
on
0 Posts
I'm pushing 400 HP/500 lb.ft. with a 355 L98.
Engine:
355 ci L98 with 52MM Throttle-Body, Ported Plenum, ASM Runners, Accel siamese-ported base plate, 24# injectors, 1.6 rollers, 218 CFM CNC-ported stock heads, Corvette Challenge cheater cam, 10.6:1 compression, Canton Road-Race Oil Pan, Ron Davis Aluminum Radiator w/Integrated oil cooler, 180 Deg. Thermostat, TPIS Jet-Hot coated headers, Formato custom chip
Dyno pull:
326.4 HP/399.3 lb/ft at wheels
397.56 HP & 487.8 lb/ft at flywheel
Engine:
355 ci L98 with 52MM Throttle-Body, Ported Plenum, ASM Runners, Accel siamese-ported base plate, 24# injectors, 1.6 rollers, 218 CFM CNC-ported stock heads, Corvette Challenge cheater cam, 10.6:1 compression, Canton Road-Race Oil Pan, Ron Davis Aluminum Radiator w/Integrated oil cooler, 180 Deg. Thermostat, TPIS Jet-Hot coated headers, Formato custom chip
Dyno pull:
326.4 HP/399.3 lb/ft at wheels
397.56 HP & 487.8 lb/ft at flywheel
Those #s are just ridiculous for a stock stroke TPI car. 
PS, ever try it in the 1/4 mile?
09-14-2009, 08:04 PM
#40
Safety Car
12.696 @ 115.76 MPH.
I found my web site that I had on the Forum...they moved it on me. Pics of the car at the track, build information, it's ALL there!
http://temp.corvetteforum.net/c4/joe90/index.shtml