Calling Mad-Mic

[Doug 87L98]

I just got an 87 coupe. I've been to the track a couple of times, and also entered the East Coast Corvette Challenge.
So far the best that I have run is - 1/4, 14.188 60', 2.019. I have had many guys tell me that that's about the best the car will do with major mods.
What have you done to get 13.1 out of your 87?

 

[Vettefan87]

Maybe I can fill in before he gets here. So let me get this straight You have ran 14.188 on a stock 87? The 60 ft times are a little low, but letting some air out of the tires should bring that down a little. What mods do you have done? Does your car have the perfomance axle ratio, the 3.07's? Is it a manual, or auto?

Now the mods that I have done starting with the free ones. Ported the ridges right behind the plenum, port matched the plenum to runner gaskets, bypassed the coolant that runs underneath the throtthe body, tried to add some timing but my car knocked, you should try to add some timing base is 6 degrees before TDC I believe.

Now for the ones that cost money. I have vortex ram air, 160 degree Tstat, 1.6 Harlan Sharp rolling rockers, TPIS long tube headers, and Muffler eliminators, which I put on yesterday. Also a Hypertech Thermo master chip. And a throttle body airfoil.

I have gteched the car a couple of times and the best I have gotten is 13.70 @ 104.9 mph, with a 5.17 0-60 time. This is launching at 1300 Rpms, and still getting a little tire spin running 35 lbs in both rear tires. Hopefully I can knock it down to 13.4's or so at the track.

If you have any questions just ask, I think Mic has a few more mods done then me...

 

[Doug 87L98]

My 87 is stock and an auto.
2.59 rear axle ratio
Z52 Suspension
K&N filter
Recently had the injecters cleaned.
Launch at 1500 RPM on DR's with 20lbs
Front tires at 40lbs
Make my runs in 'drive'
Run at Englishtown NJ

 

[Vettefan87]

I always manually shift mine at when the display says 48-4900 RPM's that way it shifts at close to 5100. It also depends on how far above sea level you are too. Those guys are wrong though about not being able to go any faster, cut the lid off your airbox, port your plenum, get it to runn cooler and you should notice a difference.

 

[Doug 87L98]

I always manually shift mine at when the display says 48-4900 RPM's that way it shifts at close to 5100. It also depends on how far above sea level you are too. Those guys are wrong though about not being able to go any faster, cut the lid off your airbox, port your plenum, get it to runn cooler and you should notice a difference.

Thanks for the info. When I get ready to 'play' with the engine I'll check in with you about porting the plenum.

 

[Vettefan87]

Yeah, do all the free mods, maybe gut your cat depending on emissions, and get a front Y without precats, or if you get the headers like I bought they come with a 3 inch front Y pipe. I think mic has a smaller Crank pulley on his car, I have considered buying one, but am not sure if the gains are worth a 100 bucks, which includes the belt.

 

[Doug 87L98]

Yeah, do all the free mods, maybe gut your cat depending on emissions, and get a front Y without precats, or if you get the headers like I bought they come with a 3 inch front Y pipe. I think mic has a smaller Crank pulley on his car, I have considered buying one, but am not sure if the gains are worth a 100 bucks, which includes the belt.

Emissions here in PA are a PITA. It has been recomended to me NOT to gut my precats. I was just thinking about installing muffler eliminaters for the sound. Will that have any performance change?

 

[Vettefan87]

If you want to see performance wise just take off your mufflers, and see since the elims will just be straight pipes, or ones that are chambered. I wanted the chambered ones but I couldnt resist the price my brother sold his to me for. The chambered ones I think add some back pressure, so you might just want the straight piped ones.

 

[Moonunit 451]

I bet if you shift it manually you're in the 13's. Those are very good times for a stock car

 

[Edmond]

Emissions here in PA are a PITA. It has been recomended to me NOT to gut my precats. I was just thinking about installing muffler eliminaters for the sound. Will that have any performance change?

The stock L98 exhaust is very strict. In fact, I believe that each stock muffler only flows through one outlet. A high performance exhaust will get you a few real ponies.

 

[Doug 87L98]

The stock L98 exhaust is very strict. In fact, I believe that each stock muffler only flows through one outlet. A high performance exhaust will get you a few real ponies.

Thanks for the info guys. I have noticed in the mornings when I start my Vette that condensation is only coming out of one pipe on each side.

 

[Mad-Mic]

lose the mufflers thats about 20-30 hp and 50 lbs. buy a front Y pipe from a 85-86 used or from ecklers or mid am with out the pre cats. you don't need them. 85 and 86 didnt' come with them. with that setup and a handfful of mods with a gutted cat i went a 13.26 @103 mph on a 1.81 60' time


here is my mod list at that time....

Current Mods:
K&N open air box, MAF descreened, TB Bypassed, 160* T-Stat, Accel Super Coil, 12* degree advance timing, !cat, no precat front Y pipe, and muffler elims. Hayden Tranny cooler. Stock 1600 rpm stall, 2.59 rear gear on 285/40/17" Goodyear F1 D3's.

i put headers on the car with the same mods and went the 13.1 at 105.84 in crap weather. the DA that day was over 700 feet.

http://www.corvettekillstories.com/photogallery/albums/Mad-Mic/Racing/L98DragRacing.wmv

since then i added a few other mods. here is my new list that is on the car.
Current Mods:
K&N open air box, MAF descreened, TB Bypassed, 160* T-Stat, Accel Super Coil, 12* degree advance timing, Cut Back AC Delco Rapid Fire plugs gapped at .050 Indexed, TPiS Long Tube Headers, !Air, Air Elim Pulley, !EGR, Crank Pulley, and KBD Targa 3" Mufflers. Hayden Tranny cooler. Stock 1600 rpm stall, 2.59 rear gear on 275/40/17" BF Goodrich Drag Radials.

so as you see with a handful of mods these cars wake up. my times were run in heavy cool fall air. the 13.18 cam in late spring last year and was 65+ degrees. there is 12's in my car i just gotta get back to the track but working 70+ hours a week it's hard too.

check out my car domain for more info.....

 

[Moonunit 451]

Most all the 86's had pre cats, I've heard that some didn't. I have an early 86 and it had pre cats

 

[rrubel]

And my early 86 didn't... Pretty sure it was the original Y-pipe, though the cat had been replaced.
[RICHR]

 

[Vettefan87]

My bros vert had precats, but that was a later year 86 obviously since it is a convertible.

 

[G Winter]

If it had cats or not may have depended on delivery state.

 

[rrubel]

New Jersey, FWIW.
[RICHR]

 

[Mad-Mic]

BTW i took the vette thru emissions today and she passed with flying colors with NO emissions equipment on the car.

previous readings with code 34 code 12 and a lazy 02 sensor with Rich flags on the data logger.

hydro carbons
state standards 220 ppm
inspection readings 531 ppm
FAIL

carbon monoxide
state standards 1.20 pct
inspection readings 1.11
PASS

carbon dioxide
state standards 6.0 pct
inspection readings 13.38
PASS



hydrocarbons
state standards 220 ppm
inspection readings 181 ppm
PASS

carbon monoxide
state standards 1.20 pct
inspection readings 0.25
PASS

carbon dioxide
state standards 6.0
inspection readings 14.24
PASS

all pass. put the heated O2 sensor in last night and had 1 or 2 bars above 1/4 tank and added 2 bottles of 91% isopropyl alcohol did the same thing on the first attempt and it failed bad. both times i didnt even bump down the timing. :L

good for another 2 years

seems like she's running really strong now. from a dead launch at 1200 rpm on DR's she laid about 100 ft of posi marks before i let out....lol i guess i nailed the tune finally

time for the dyno.......

 

[Vettefan87]

Damn...I wish my car could do that.

 

[Edmond]

Buddy of mine told me a few years ago that if a car is properly tuned up, it will pass without any emissions equipment. I really didn't believe him but Mic is living proof!