What does an L98 C4 'Vette need to be a decent/reliable track car?

If I wasn't shopping for a house right now, I'd buy this. But it definitely got me thinking.

http://madison.craigslist.org/cto/5413744498.html

L98/6-speed cars are starting to show up for less and less. Like, cheap enough that they make a Camaro or Mustang that needs all kind of bracing to keep from being a wet noodle seem like a silly investment by comparison. I've been a tried-and-true import guy my entire life so I know pretty much nothing of V8s other than the fact that LS1 is the classic swap answer...but I have a soft spot for C4 Corvettes and prices like these are hard to ignore.

I know the LT1 is a big improvement in a lot of ways, but say I were to pick this thing up. What do I need to reliably go tear up Road America? What modifications are really worth doing on the L98? Does the C4 need much beyond decent rubber to handle well? All of the Corvette forums seem to answer this question with "spend $5000 at X Corvette shop," but my thought is that there's gotta be a more Grassroots way...it's just a Chevy V8 under there after all, right? Miniram intakes seem to come up a lot as a great way to add power while letting the engine rev, but that setup alone is about $1000 all said and done. Perhaps worth it, but is there no cheaper alternative?

Basically, with $2k or so to spend on top of purchase what would I want to look at to get this track-ready?

That is new enough to have the upgraded front suspension geometry (88-ish, iirc) so bushings all around plus good shocks and tires will get you most of the way there.

Were it mine I'd do a basic tune up and run what is in it until something breaks, then drop in a 6.0L truck motor and stand alone harness.

Is there anything to worry about as far as oiling with these engines? Turns 9 & 10 (aka the Carousel) at RA is a super fast right-hander that can cause oil starvation in some engines; I've seen that some companies offer massive oil pans for the L98...is this something I'd want to look into? Even an L98 C4 is a lot more car than I'm used to...never had a car with 275-series rubber, let alone stock

We ran an 88 with a 6 speed (blew up the 4+3) for years in nasa se.

Canton road race pan and zr1 oil cooler. Home ported and polished intake and heads. Tpis headers, Flowmaster exhaust. 4 point bolt in roll bar and 5 point harness. C5 calipers and rotors on the front, wildwood h pads. Stock rear, wildwood pads. Vb&p springs, zr1 sway bars, fresh bilstien shocks, and that's about it. It was a daily driver super car. Sure, the c6 z06 was faster. But....

God, I miss that car.

On top of the above suggestion for a bigger pan and an oil cooler, I'd make sure to add an oil temp gauge (and an oil pressure gauge if it doesn't have one already).

My immediate first thought was Vette Kart

https://www.youtube.com/watch?v=GD3y7ylpqO8

Plan on spending all of that 2k on safety gear if you don't have it already.

They don't need much in the handling department; just replace everything worn out, get some good shocks, and put good tires on it.

As for cheaper intake options, I've seen two. One is to modify an LT1 intake to fit the earlier motors. Two is to use a four barrel carb style intake with port injectors and an elbow adapter to an LS1 type throttle body.

Look at the Danger Zone build thread for ideas. Keep in mind he's working within a rule set, so not everything might apply, but it should give you something to think about.

I keep looking at ads for them as a replacement for the MR2 (plus we did own a C4 before and I liked it before the shop who "help" fix some cooling issued ended up helping me to cook the engine...). Ours had the Z51 package and I was pretty impressed with the handling.

Can the oil pan be changed with the engine in place or is that an engine out job?

oil pan can be changed with engine in car. it's not horrible under there, starter was annoying though. my car is so screwed i'm considering an ls swap.

pointofdeparture wrote: I All of the Corvette forums seem to answer this question with "spend $5000 at X Corvette shop," but my thought is that there's gotta be a more Grassroots way...it's just a Chevy V8 under there after all, right? Miniram intakes seem to come up a lot as a great way to add power while letting the engine rev, but that setup alone is about $1000 all said and done. Perhaps worth it, but is there no cheaper alternative?

Exactly, it is just a small block Chevy. The L98 heads aren't terrible, they are one of the better tradition small block Chevy heads out there (GM used them on the ZZ 383 crate motors for years). I'd say toss the TPI rather than beat your head against the wall with that and go with an Edelbrock RPM Air Gap intake and a good tuned carburetor, call Comp Cams for a good cam recommendation and some roller rockers.

I took out the oil pan on Jack stands on my L98( cracked it on a speed bump... Welded it back up) just disconnect the battery first: the starter hot is close to the air injection line: my socket welded itself.

The stock dash has an oil temp read out.

The stock clutch/flywheel has a bad internet rep: I changed mine out to an al one piece to find out it was just bad hydraulics. Also, the $100+ clutch flex line can be replicated with $15 in brake hose + line.

I chose the overfill the sump with an extra quart for racing instead of getting a nice pan... Sustained right hand turn pulled oil into the intake from the pcv system. Just smoke show, no harm.

I have an lt1 intake sitting on a shelf for a poor man's miniram.. the vette is long gone.

Opening the stock exhaust/better cats/ downpipe helped a lot.

Of trivial matters: I 're-programmed the ecm to eliminate the stock security system after getting stranded hundreds of miles from home. Once you "socket" the chip, reprogramming becomes easy.

Enjoy !

NickD wrote:

pointofdeparture wrote: I All of the Corvette forums seem to answer this question with "spend $5000 at X Corvette shop," but my thought is that there's gotta be a more Grassroots way...it's just a Chevy V8 under there after all, right? Miniram intakes seem to come up a lot as a great way to add power while letting the engine rev, but that setup alone is about $1000 all said and done. Perhaps worth it, but is there no cheaper alternative?

Exactly, it is just a small block Chevy. The L98 heads aren't terrible, they are one of the better tradition small block Chevy heads out there (GM used them on the ZZ 383 crate motors for years). I'd say toss the TPI rather than beat your head against the wall with that and go with an Edelbrock RPM Air Gap intake and a good tuned carburetor, call Comp Cams for a good cam recommendation and some roller rockers.

If you upgrade the intake, an lt4 Hotcam and self aligning roller rockers (i think the hot cam is designed for 1.4:1) would be grassroots.

1.6:1 roller rockers. Self aligning allows you to not modify l98 heads

Since it would be a track car the stock seats can be thrown up for sale or the garbage. I have no idea how people handle the stock seats. They hit my shoulders all wrong with their weird needlessly aggressive bolstering. Also the ergonomics are a little weird. That's all I have to say for them. Well that and C5s are a hell of a lot more comfortable with normal ergonomics.

clutchsmoke wrote: Since it would be a track car the stock seats can be thrown up for sale or the garbage. I have no idea how people handle the stock seats. They hit my shoulders all wrong with their weird needlessly aggressive bolstering. Also the ergonomics are a little weird. That's all I have to say for them. Well that and C5s are a hell of a lot more comfortable with normal ergonomics.

Yeah, the C4 interior is garbage. I dunno how big the OP is, but at 6'3" and 235lbs, I just about throw my back out every time I get in and out of one of these.

In reply to MadScientistMatt:

agreed. replace all the worn out stuff in the suspension, get some new brake fluid and pads, spend the rest on beer and bbq. its not the fastest ride but it will go all day then get you home.

In reply to NickD:

I'm 6'2" and 185lbs, so thinner but about as tall. I will say that I've heard almost nothing good about C4 ingress/egress, and I typically hate GM seats, so hypothetically a nice set of used Recaros would be on the list.

I'm about your height and a bit heavier. Getting into the C4 was a bit weird and more involved than your usual car, but I found it quite comfortable after getting in. It's mostly just a low seat with a really, really big door sill.

NickD wrote:

clutchsmoke wrote: Since it would be a track car the stock seats can be thrown up for sale or the garbage. I have no idea how people handle the stock seats. They hit my shoulders all wrong with their weird needlessly aggressive bolstering. Also the ergonomics are a little weird. That's all I have to say for them. Well that and C5s are a hell of a lot more comfortable with normal ergonomics.

Yeah, the C4 interior is garbage. I dunno how big the OP is, but at 6'3" and 235lbs, I just about throw my back out every time I get in and out of one of these.

That and the lack of foot space with the manual. With 3 pedals there's no place to rest your left foot. It's tight, hot and uncomfortable. Very few seats will fit in the narrow space provided etc. Not a fun place to spend long hours.

But.... they are a hoot and that L98 has torque for weeks. You're just above idle? No problem, here's 300ftlbs of torque. At the rear wheels. Sure there's no revs there bu who cares with that much torque? I almost think this should have been an RV engine.

pointofdeparture wrote: In reply to NickD: I'm 6'2" and 185lbs, so thinner but about as tall. I will say that I've heard almost nothing good about C4 ingress/egress, and I typically hate GM seats, so hypothetically a nice set of used Recaros would be on the list.

I've seen you get in and out of an Alfa Spider, and I've been in and out of a couple C4s. You should have no problem.

pointofdeparture wrote: http://madison.craigslist.org/cto/5413744498.html

For a mere $5k that's mighty tempting. There's a guy that I see out at High Plains with one of these. It's surprisingly fast and he seems to have almost no money into it.

In reply to RealMiniParker:

That Spider was nothing. You should have seen the X1/9 procedure

Bobzilla wrote:

NickD wrote:

clutchsmoke wrote: Since it would be a track car the stock seats can be thrown up for sale or the garbage. I have no idea how people handle the stock seats. They hit my shoulders all wrong with their weird needlessly aggressive bolstering. Also the ergonomics are a little weird. That's all I have to say for them. Well that and C5s are a hell of a lot more comfortable with normal ergonomics.

Yeah, the C4 interior is garbage. I dunno how big the OP is, but at 6'3" and 235lbs, I just about throw my back out every time I get in and out of one of these.

That and the lack of foot space with the manual. With 3 pedals there's no place to rest your left foot. It's tight, hot and uncomfortable. Very few seats will fit in the narrow space provided etc. Not a fun place to spend long hours. But.... they are a hoot and that L98 has torque for weeks. You're just above idle? No problem, here's 300ftlbs of torque. At the rear wheels. Sure there's no revs there bu who cares with that much torque? I almost think this should have been an RV engine.

aside of my right leg getting really freaking hot, it's not a bad space to spend a day.