Newbie c4 owner in need of help...GRM $2016 challenge build
05-17-2016, 12:37 PM
#1
Newbie c4 owner in need of help...GRM $2016 challenge build
Hi guys...need some advice on how too use a limited budget. For those unintiated grassroots motorsports magazine sponsors a competition for budget builds of an Autocross/drag car limitted to a $2016 budget including price of car. Any parts you sell off your car can be added back to your budget. As smuch I've posted for sale ad in c4 classifieds to gett rid of parts I don't need.
Fortunately the, old c4 I picked up has good driveline. Andl I'm going thru the brake system now. (fortunately oem brake components are excluded from budget as a safety item).
So advice I need now is what to spend limited budget on. I'll only have about $650 left unless I sell some parts. In order of need I see shocks and.bushings as ,first. Shocks next...obviously a coil over set would be ideal but that'd push me way over budget. NeXt order of business, would be lowuering 10 inchl rear bolts. Maybe offset lca Bushings?
Thanks in advance.
Jim
Just so you know, I'm not bs-ing , heres at pic of project car I picked up for $500...my apologies to the purists in here
Fortunately the, old c4 I picked up has good driveline. Andl I'm going thru the brake system now. (fortunately oem brake components are excluded from budget as a safety item).
So advice I need now is what to spend limited budget on. I'll only have about $650 left unless I sell some parts. In order of need I see shocks and.bushings as ,first. Shocks next...obviously a coil over set would be ideal but that'd push me way over budget. NeXt order of business, would be lowuering 10 inchl rear bolts. Maybe offset lca Bushings?
Thanks in advance.
Jim
Just so you know, I'm not bs-ing , heres at pic of project car I picked up for $500...my apologies to the purists in here
Last edited by Dueller; 05-17-2016 at 12:43 PM.
05-17-2016, 02:08 PM
#2
Safety Car
Can you fabricate suspension parts yourself and not take a budget hit? I raced a C4 in NASA ST2 for years, and one of the single biggest impacts i found to the handling was rear toe and camber rods. There are several kits off the shelf but they'll set you back $300-500 bucks. All you need to make your own is a threaded tube and some $25 heim ends and you'll see a massive improvement.
I would ditch the C4 ABS also and run a standard set up with a proportioning valve.
I ran coil overs so I am not sure what adjustment you have with the stock springs.
I would ditch the C4 ABS also and run a standard set up with a proportioning valve.
I ran coil overs so I am not sure what adjustment you have with the stock springs.
Last edited by ScaryFast; 05-17-2016 at 02:10 PM.
05-17-2016, 02:54 PM
#3
Thanks, scary. Just the kind of info I'm looking for. The competition encourages fabricating your own parts and your only have to put materials in you budget so I'd be real interested in the rear suspension mod you're talking about.
Thank you for your input.
Jim
Also was wondering about deleting the abs...as I understand the stock system on a 89 its pretty basic and doesn't seem that effective.
Thank you for your input.
Jim
Also was wondering about deleting the abs...as I understand the stock system on a 89 its pretty basic and doesn't seem that effective.
Last edited by Dueller; 05-17-2016 at 02:59 PM.
05-17-2016, 04:10 PM
#4
Advanced
Keep this forum up to date with your build! I'm a GRM subscriber and have followed the yearly challenge for a while. A few team mates and I also run a 1991 BMW 535i in 24h of Lemons, so I love seeing other budget builds.
There's typically a few 10-second drag cars and some competitive autocrossers. Your '89 should be reasonably competitive in both categories and will probably also do well in concours. You could place pretty high if you've got good drivers.
Does the car have any existing modifications? Do you plan to street drive it and keep it emissions legal? Can you weld?
There's typically a few 10-second drag cars and some competitive autocrossers. Your '89 should be reasonably competitive in both categories and will probably also do well in concours. You could place pretty high if you've got good drivers.
Does the car have any existing modifications? Do you plan to street drive it and keep it emissions legal? Can you weld?
05-17-2016, 05:43 PM
#5
Team Owner
Member Since: Mar 2001
Location: Boston, Dallas, Detroit, SoCal, back to Boston MA
Posts: 30,606
Received 239 Likes
on
167 Posts
Looking forward to seeing how you do
bang for the buck ditch the TPI and go carb
the engine will breath a lot better
a miniram would be better, or you could convert an LT1 intake
but I don't know if that would kill you budget
bang for the buck ditch the TPI and go carb
the engine will breath a lot better
a miniram would be better, or you could convert an LT1 intake
but I don't know if that would kill you budget
05-17-2016, 05:57 PM
#6
Hey, zwoo...I was a little wary of coming to a corvette forum with this request for assistance for fear of the purist backlash but this one seemed the most welcoming. And this is my first vette....I'm a 911 owner so I have that rivary with this crowd. Lol
But I was able to pick this car up so cheap and the body damage looks worse than it is....it was bashed around in a shop when a tornado came thru 2 or so years ago. Fresh rebuilt motor and tyranny right before it was damaged. Parked under a tarp for 2 years while owner arguing with insrance could company.
In state I live in it qualifies as an antique so smog and inspection exempt. Cats long gone. Only brake lights required. So I can remove headlights and just run fogs an be legal. Its an auto but that's a plus I'll explain later. 3.o7 performance rear end. Otherwise a plain Jane c4.
Plans are to keep it simple this year....vet it running right, stopping and turning and save further mods for down the road. Gonna try to take a little weight out of it and firm up suspension
Everybody who's working on it are pretty handy....one is a senior automotive envineer with. NIssan,. Other guys are hardcore racers from various bakgrounds. And a friend of mine is John Thomas and I might get him to enter the autocross...you may have heard of him. He holds the scca record for consecutive national solo II championships at 17....he might be a good choice, eh?
But I was able to pick this car up so cheap and the body damage looks worse than it is....it was bashed around in a shop when a tornado came thru 2 or so years ago. Fresh rebuilt motor and tyranny right before it was damaged. Parked under a tarp for 2 years while owner arguing with insrance could company.
In state I live in it qualifies as an antique so smog and inspection exempt. Cats long gone. Only brake lights required. So I can remove headlights and just run fogs an be legal. Its an auto but that's a plus I'll explain later. 3.o7 performance rear end. Otherwise a plain Jane c4.
Plans are to keep it simple this year....vet it running right, stopping and turning and save further mods for down the road. Gonna try to take a little weight out of it and firm up suspension
Everybody who's working on it are pretty handy....one is a senior automotive envineer with. NIssan,. Other guys are hardcore racers from various bakgrounds. And a friend of mine is John Thomas and I might get him to enter the autocross...you may have heard of him. He holds the scca record for consecutive national solo II championships at 17....he might be a good choice, eh?
Last edited by Dueller; 05-18-2016 at 06:19 PM.
05-17-2016, 06:24 PM
#8
Thanks for your thoughts
Jim
Last edited by Dueller; 05-17-2016 at 06:28 PM.
05-18-2016, 08:53 AM
#9
Le Mans Master
Inside the console there is a list of option codes.
Put them here in the thread.
One thing that woke my 92 up was replacing all the suspension bushings.
Don't know what the kits are running these days, but those old rubber bushings are going to have lots of play!
Put them here in the thread.
One thing that woke my 92 up was replacing all the suspension bushings.
Don't know what the kits are running these days, but those old rubber bushings are going to have lots of play!
05-18-2016, 09:21 AM
#10
Safety Car
Here is the link to the parts i am talking about:
https://www.vbandp.com/auto-parts/c4...ir-detail.html
https://www.vbandp.com/auto-parts/c4...ds-detail.html
I don't have the car but i have most of my records. I can dig up the size of the heim ends as i replaced them a few times over the years. Then just make a rod to capture them and you're done.
I did bushings as well, I have all of those PN's on a list if you need it. However, i have a feeling buying new ones will quickly eat into your budget.
To delete ABS all i did was run new brake lines straight from the master to the calipers. I used a GM truck master for better feel but the stock one is probably fine to start.
https://www.vbandp.com/auto-parts/c4...ir-detail.html
https://www.vbandp.com/auto-parts/c4...ds-detail.html
I don't have the car but i have most of my records. I can dig up the size of the heim ends as i replaced them a few times over the years. Then just make a rod to capture them and you're done.
I did bushings as well, I have all of those PN's on a list if you need it. However, i have a feeling buying new ones will quickly eat into your budget.
To delete ABS all i did was run new brake lines straight from the master to the calipers. I used a GM truck master for better feel but the stock one is probably fine to start.
Last edited by ScaryFast; 05-18-2016 at 09:25 AM.
05-18-2016, 10:46 AM
#11
Team Owner
Member Since: Mar 2001
Location: Boston, Dallas, Detroit, SoCal, back to Boston MA
Posts: 30,606
Received 239 Likes
on
167 Posts
Thanks for input Brian...believe me we would all like to go to carb...we're a bunch old geezers. Lol. What does carb conversion entail? Can we go swap meet shopping and find parts for a typical small block...edlebroch performer and a holly 4 bbl?
Thanks for your thoughts
Jim
Thanks for your thoughts
Jim
took this from a carb swap thread
Are you still doing the swap? I just ran across this thread. I did the swap last October on my early 86 with a 355 crate engine swap and have been trying a few different carb/intake combinations since. I have gotten a lot of flack for doing it from the purists, but it was something I wanted to do, an added bonus is it makes everything a lot more simple and easier to work on (frees up a ton of space under the hood). For what it's worth, below are the changes I made:
-Intake manifold (weiand 7547 xcelerator single plane initially , now I have weiand 8120 dual plane - both fit, but barely)
-Carb (Holley 770cfm street avenger initially, now I have Holley 600cfm (pn 80457), the 770 was too big for my 355ci, but should work well with 383)
-Fuel pressure regulator
-Fuel pump from TBI - the stock pump blew up 2 FPRs so I switched to the TBI pump ~14psi if I remember correctly
-Hotwired the cooling fan to run all the time
- Distributor (MSD street fire vac. advance)
- 1.25" Drop base air cleaner with filter lid
- 700r4 kickdown bracket
- throttle cable/tv cable bracket - I reused the stock throttle cable and tv cable
Also I have a built 700r4 with 2800 stall, 3.73 rear end so your stall and rear end will also be a part in determining which intake you want to use.
It runs very strong with 280 rwhp and 390 rwtq with the dual plane and 600cfm carb. I'm sure you already know just be prepared to let it warm up way more than with the TPI and a little harder to start at times, even with elec. choke. By selling all the TPI stuff I was just shy of breaking even with the swap. That's all that I did off the top of my head, but I'm sure there are a few more odds and ends that I'm missing out.
-Intake manifold (weiand 7547 xcelerator single plane initially , now I have weiand 8120 dual plane - both fit, but barely)
-Carb (Holley 770cfm street avenger initially, now I have Holley 600cfm (pn 80457), the 770 was too big for my 355ci, but should work well with 383)
-Fuel pressure regulator
-Fuel pump from TBI - the stock pump blew up 2 FPRs so I switched to the TBI pump ~14psi if I remember correctly
-Hotwired the cooling fan to run all the time
- Distributor (MSD street fire vac. advance)
- 1.25" Drop base air cleaner with filter lid
- 700r4 kickdown bracket
- throttle cable/tv cable bracket - I reused the stock throttle cable and tv cable
Also I have a built 700r4 with 2800 stall, 3.73 rear end so your stall and rear end will also be a part in determining which intake you want to use.
It runs very strong with 280 rwhp and 390 rwtq with the dual plane and 600cfm carb. I'm sure you already know just be prepared to let it warm up way more than with the TPI and a little harder to start at times, even with elec. choke. By selling all the TPI stuff I was just shy of breaking even with the swap. That's all that I did off the top of my head, but I'm sure there are a few more odds and ends that I'm missing out.
05-18-2016, 01:39 PM
#12
Kinda hard to read some
05-18-2016, 02:11 PM
#13
Since everyone is so helpful I figure you needed a full view of "our" forum project. Obviously rough...it was tossed around inside a shop when a tornado hit. My pilot/composite engineer assures me he can repair left rear damage.
I was told by seller it had recently rebuilt engine and tranny but no documentation...yeah right. Lo a d behold when I got it in air bottom of engine and trans looks brand new...spotless...freshly painted oil pan. Maybe it is fresh. Once we got rid of old bad gas and new fp sock and filter it started right up. No smoking at all. Maybe it is a fresh rebuild. Now that it's run ing have to replace master cylinder and get brakes sorted. Then on to budget suspension refresh with new bushings etc.
It's rough but hey...it was only 500 bucks. Paint is all original and it may buff out OK. No indication of accident damage except tornado quarte. Damage.
I appreciate your guys help so much.
I was told by seller it had recently rebuilt engine and tranny but no documentation...yeah right. Lo a d behold when I got it in air bottom of engine and trans looks brand new...spotless...freshly painted oil pan. Maybe it is fresh. Once we got rid of old bad gas and new fp sock and filter it started right up. No smoking at all. Maybe it is a fresh rebuild. Now that it's run ing have to replace master cylinder and get brakes sorted. Then on to budget suspension refresh with new bushings etc.
It's rough but hey...it was only 500 bucks. Paint is all original and it may buff out OK. No indication of accident damage except tornado quarte. Damage.
I appreciate your guys help so much.
05-18-2016, 04:08 PM
#14
Le Mans Master
Gonna keep those wheels?
If so you would have issues going from JL9 to J55 or c5 conversion
Sorry thats the brakes code. JL9 are kinda small. J55 is better
If so you would have issues going from JL9 to J55 or c5 conversion
Sorry thats the brakes code. JL9 are kinda small. J55 is better
Last edited by jaa1992; 05-18-2016 at 04:09 PM.
05-18-2016, 05:09 PM
#15
Just gonna try to make them work best way I can
Last edited by Dueller; 05-18-2016 at 05:12 PM.
05-18-2016, 06:13 PM
#16
Reduce weight. Cut the roof off, replace the front windshield with a windscreen, and brace the bodywork with pieces of aluminum angle.
Don't lower the car with lowering bolts because that gives up spring pre-load.
Add big swaybars.
Add 200tw autocross tires.
Weld the frame junctions.
Replace the mufflers with generic race mufflers
.
Don't lower the car with lowering bolts because that gives up spring pre-load.
Add big swaybars.
Add 200tw autocross tires.
Weld the frame junctions.
Replace the mufflers with generic race mufflers
.
Any other ideas you guys got?
Last edited by Dueller; 05-18-2016 at 06:55 PM.
05-18-2016, 09:17 PM
#18
Melting Slicks
With an automatic you're going to have a really hard time getting the transmission to live for very long without adding a lot of cooling. The lock up clutch won't lock when the gas pedal is on the floor, so you're running with slip all the time an it generates tons of heat. Big trans cooler is required for sure. There was on guy on here that had a C4 auto and was running track days, He struggled for a long time until he got enough tranny cooling to where he could run a 20 minute session on the track without melting down the transmission.
Not say'n it can't be done but you are going to need a really big cooler to get it to live for very long.
Also the rear end in that car isn't the Dana 44, so life of that could be an issue too.
I know you've got to do this on the cheap, but get as much trans a diff cooling as you can or it's going to be sitting in the pits with the tranny boiled to a crisp if you don't.
I know that beggars can't be choosers, but the automatic c4's cars are really boulevard cruisers and aren't very well suited to any kind of track work. Your car has the soft springs, soft suspension bushings, smaller radiator, small brakes, small diff, no power steering cooler (which the Z51 cars had for good reason an is another cooler that you need to add or you're going to be boiling the PS fluid too)..
Not likely that you can do this for the budget, but you need to spend some time at the wrecking yards looking for the parts from a stick shift car or it's not likely you could run for even an hour on the track without backing off an cooling the car down every other lap or two.
Not say'n it can't be done but you are going to need a really big cooler to get it to live for very long.
Also the rear end in that car isn't the Dana 44, so life of that could be an issue too.
I know you've got to do this on the cheap, but get as much trans a diff cooling as you can or it's going to be sitting in the pits with the tranny boiled to a crisp if you don't.
I know that beggars can't be choosers, but the automatic c4's cars are really boulevard cruisers and aren't very well suited to any kind of track work. Your car has the soft springs, soft suspension bushings, smaller radiator, small brakes, small diff, no power steering cooler (which the Z51 cars had for good reason an is another cooler that you need to add or you're going to be boiling the PS fluid too)..
Not likely that you can do this for the budget, but you need to spend some time at the wrecking yards looking for the parts from a stick shift car or it's not likely you could run for even an hour on the track without backing off an cooling the car down every other lap or two.
Last edited by Solofast; 05-18-2016 at 09:19 PM.
05-18-2016, 09:37 PM
#19
Melting Slicks
Offset bushings are nice but you can just grind down the conical spacers at the top control arms and get some more negative camber, which is sorely needed in the front. Take the rear spacers and put them in the front and cut down the front spacers to almost nothing. This will get you more negative camber and costs nothing. Set the rear at -1.5 degrees of negative camber, look for a set of Z07 springs.
The following users liked this post:
Dueller (05-18-2016)
05-18-2016, 09:56 PM
#20
Solo....great advice. This car will only be used for a/x....and infrequent drag race at the challenge. One of the reasons I went with auto other than the car being so cheap was personal medical issue. About 3 years ago I had a stroke and as a result I've lost some ability on my left side. Before that I did rr on motorcycles and cars hpde etc. Was even an instructor for several years. Doing this as therapy to get back into some type of motoring competition. So going back into local AX where I started 35 years ago. So that's why the auto. I am scouring for big trans cooler.
Any reccomendation advice appreciated
What do you think about generic coil over set up ....what spring rates?
If I were doing a non-GRM $2016 build I'd certainly do it different....but figuring out how to build a fun toy on the cheap is kinda entertaining
Any reccomendation advice appreciated
What do you think about generic coil over set up ....what spring rates?
If I were doing a non-GRM $2016 build I'd certainly do it different....but figuring out how to build a fun toy on the cheap is kinda entertaining
Last edited by Dueller; 05-18-2016 at 10:01 PM.