Only just seen this, Ok !991 Z28 350 tpi 700r4. 120000 on the clock only thing done to the car is 4th gen interior and a rebuilt lsd everything is else is as GM intended. !st ever trip to the track and the best time of the day was 14.01@ 98 mph. This was at Santa pod raceway in the UK on a cloudy day.

 

Ok I thought I posted this but never mind will try again. 1991 350 Z28, the only thing done to the car was a fresh built lsd and a service thats it. The car was as GM intended from the factory. 14.01@ 98mph and thats a standing quarter on street tyres with jack and spare in the trunk. That was also my first time at the track.

 

There are a lot of simular post about this.
I posted this back in 2007.

145,000+ miles on the odometer

fastest 1/4 mile time:
13.525 @ 99.95 mph
@ KCIR 11/12/2006

Same night:
fastest 1/4 mile speed:
13.611@ 100.87
@ KCIR

Many 1/8 mile passes in the 8.88 sec range.

Race weight = 3660 lbs. with me in it.
I've been cash poor for a while now.
so no futher mods have been added.

Added:
Jet TPI air foil...
K & N air filters...
Gutted air boxes...

TPIS plug wires...
Bosch platinum plugs...
Throttle body coolant bypass...
Empire Inland aluminum drive shaft...

March steel underdrive pulleys # 4405...
Edelbrock ceramic coated TES headers...
Flowmaster American Thunder 3\" Catback...
Catco dual cat replacements...

TPIS MAT relocation kit...
Meziere electric water pump...
Motive Gear master kit & 3.42 gears...
Spohn adj. torque arm...
UMI lower control arms & relocation brackets...
UMI adj. pan hard bar

 

stock 305 tpi 15.2 at 88mph will get new times soon the moter has a top in build accel lower,22lb inj,arizona speed shop runners,custom trans,stock gears hopeing for high 13s

 

anyone run with mods same as mine?

MAF L98 fully built
SLP Air Foil on Stock Throttle Body
Ported Plenum
Ported SLP Runners
TPIS Big Mouth Base
Stock Heads
Dyno Dons 1 3/4 Headers
3" Y Pipe
3" Cat
3" Flowmaster Cat Back
3.73 Posi
Firestone Firehawk 245 50R16 Tires
Built Tranny 2100 Stall

Convertible

I know the verts are heavier but im hoping for mid 13's - maybe too much to hope for on the stock heads

 

1/4 mile times:

1989 GTA 5.7L T-top car, 3.27 rr, single catalyst

When stock, she ran 14.3 @ 96
A few mods - cold air inlet, flowmaster muffler, underdrive pulley, and performance resource chip, she ran 13.9@101
With AFR Cylinder heads, Superram, 58mm tb, she ran 13.1@109
Changing to the 6.3L from the 5.7L, she went down to 12.2@115 mph

 

I don't think I updated from my trip to the track last Sept. 4010lb 89 Jag convertible, 89 Camaro based motor, stock cam, 1.6 rr rocker, ported plenum, edelbrock runners, tpis intake, 52mm tb, 22lb injectors, shorty headers, emissions legal exhaust, 700r, 2800 stall lockup converter, 3.23 gear with dot radials, non drag radials. With a mild, over the internet tune that easily passes emissions, the car ran a new best of 13.39 @ 102. This far exceeds my expectations for this combination. My fear is they always run the best, just before they blow up!! lol!

 

87 IROC L98 auto w/ B&M shift kit, SLP converter, 3.27 9 bolt, Flowmaster 2 on the left exhuast.. "free mods" It ran a best of 14.2 @ 93ish dynoed 195 hp 280 tq

86 Firebird L98 T5 swap SD conversion, 3.42 rear.. Flowmaster dual cat exhaust.
14.3 @ 94ish never got it on a dyno, but it was the engine that was in the 87 originally.

88 IROC L98 SD conversion, T56, Dana44 w 4.10 gears, SLP 1 3/4" headers, Magnaflow exhaust 14.3 @ 93 dynoed 220 hp 370 tq

 

Stock 5.7 tpi 1\8 mile
60 Ft 2.04
9.46 et
73 mph

I drove 30 miles down the interstate at 75mph
Pulled right up and ran 3 times down the track (slow Sunday)
Turned around and drove 30miles back home
No mods

 

89 formula
305 tpi
6.8 psi boost
Dyno don headers no. Cat
3" catbck
3.73 gears
Meth injection
KN intake
Ac
Air pump

60. Ft 2.22 s
1/8 9.333 s
1/4 14.5s
95.3 mph

Only able to do two runs and first was disaster

Should I be expecting more? I thought I would do better

 

Sn blowers are JUNK. Thats 1 of your problems.

 

I had a 91 Z28 LB9,Auto. It had no cat,smog delete,3 in exhaust, an aftermarket chip so pretty much bone stock. I was very surprised when it turned a 14.76 one cool fall evening. It would typically turn 14.85-15.10 depending on the weather, our summers are horrendous down here.

 

60' 1.57
330' 4.79
1/8 7.50
MPH 90.81
1000' 9.84
1/4 11.83
MPH 112.98

91 Vette, 383, TPIS 113 heads, LPE 219 cam, AS&M runners, accel base, ported plenum

 

Those are darn good numbers. Congratulations.

 

305 tpi 120k
Bone stock 86 tranny
Magnaflow exhaust
1/4 on 87 oct = 16.92 was my first run
After warming up I got 16.83

 

There's gotta be more to it. A bolt on LB9 is capable of mid 14s. With meth and boost he should be in the 13s, at least. Something has to be wrong with it.

Unless those blowers are just THAT bad, but I don't see how that's even possible.