3rdBird

iTrader: (1)

Why so many carb'd cars?

87_GTA_5.7

Mine is. Im not done with it yet but I would think Id be in the 11s easy on motor and 10s on the bottle.

Old set up with Nitrous 12.8s at 108-110 MPH.
Bone stock L98 with a 75 shot, Nothing other than the nitrous.
Eld. Shortys with SLP Loud mouth
Stock 700R4..didnt last long..(4 rebuilds in a year)
Moser 9in 3:70s
Micky T DRs on the GTA Wheels.
Suspension..Spohn Panhard bar and Control arms

NOW
350 .040 over
Eagle Stroker kit (ESP 12011).. what is that like 387-388 CID? I dont know
Comp Cams 260/262 .630/630 R106s
Demon 750 Carb
Wiend Team G High Rise
Brodix Race Heads Stainless Valves
Motor Build by Boyds Racing in Norman, OK.
500 hp on 93 octain.

Build for Nitrous.. prob only spray a 150-175 shot.

Tranny now
Performabuilt 700R4 3000 Stall http://performabuiltautomatics.com/G...00r4_4l60e.htm Great people..

Supsenion
Cheap Coil over in the front with Lakewood 90/10s
Spohn Adj Torque Arm
" " Panhard bar
" " Control Arms
and BMR Subframe con.
Pretty much Stock weight of an 87 GTA


One thing Do I need the 50/50s for the rear?

If I can drive and hook what does it look like?

skinny z

11's all day.
----------

Suited for drag racing.
Less expensive too.

SLP-GTA

iTrader: (1)

still have factory exhaust manifolds?? nothing done to the engine??

Orr89RocZ

iTrader: (20)

you SHOULD have alot more than 500hp on that setup 550 atleast. should go bottom 11's at over 123-124 mph in a pretty light 3400-3500 lb raceweight. my car is milder than that and i run 11.50's, about 400whp which is 480-500 on crank

87_GTA_5.7

They hooked up my buddys motor for his nova on the dyno..pretty close set up but with eldelbrock heads and smaller cam and his made 490 at the flywheel and they said mine should be higher than that. I guess his heads arent really as good as mine idk. Im going down to OK Next weekend or the next to get it and well see how seh does. It would be bad *** to pull a tire or both!!

Orr89RocZ

iTrader: (20)

i think you will be happy with it

91RamAir Formula

So what do you think about going with 1.7 RR's on my Setup to bump up the lift a little more or should I just step up to a solid roller and keep the 1.6's and I definately agree I need more Stall, I'm going for a 3600 when I switch over to a TH350 probably this winter.

Orr89RocZ

iTrader: (20)

i woudlnt try 1.7's. i was told it starts to mess with valve train geometry and is hard to control at higher rpms with the extra long pushrods

you may get away with a 1.65 ratio but i'd just keep the 1.6's for now

3rdBird

iTrader: (1)

Edelbrock 1 3/4" w/ air inj tubes...Otherwise, Stock.

skinny z

Curious as to how much has changed in the 8 years since this thread was active.
Lots of carbed Gen I small blocks doing their thing then.
I bet there are a lot more in the 12 second crowd now. Probably plenty of stock or nearly stock LS swaps out there too.
While I've been in the 12's for a while now, I haven't yet tested my latest combination on top of the old 355. While I doubt 11's are in the works, it's gotta be faster than before. Personal best with the unported heads and 274 cam was a corrected 12.4 @ 108 (+/-). I'm thinking a couple of tenths with ported heads and 288 cam. Maybe a couple of more tenths with a better converter and true dual exhaust. Maybe 11's.

Jorlain

iTrader: (4)

What were you running for a converter and exhaust? I'll be interested to see what you end up with since our builds are so similar, although your cam is a little more aggressive.

skinny z

When I ran the XR276HR Vortec headed 353, I had a TCI 10" converter and Hedman LT (but really mid-length) headers into a 2 1/2" x 2 to 3" y-pipe. From there to the back via a Flowmaster 3" cat-back (with no cat) to a crappy Flowmaster muffler in the stock location.
The exhaust certainly cripples the cars performance at the track. I can gain a tenth and almost 2 MPH in the 1/8th just by bypassing the muffler with a cut-out placed just in front of it at the turn.
The converter allowed me to foot brake to about 2200 RPM at the most. Flash stall was arguably around 3500 judging by the tach when the car was on the chassis dyno.
Race weight waiting at the tree is 3650 lbs.
12.75 @ 105.93, 8.082 @ 83.39, 1.74 60’ (Density altitude was 2050').
12.449 @ 108.551 MPH corrected.

Jorlain

iTrader: (4)

Are you planning on staying with the 3" cat-back, or do you plan on moving up in diameter?

skinny z

I'm thinking I'll redo the exhaust in it's entirety. New headers although I'll probably stick with 1 5/8". From there I'll go with Holley's Black Heart duals. That'll bump up my intermediate pipe sizes from a single 3" to 2 x 2 1/2" but more importantly, I'll have a pair of mufflers to work with rather than the single I have now. Following the generally applied rule of 2.2 CFM/ HP, that means instead of a single muffler with an 800+ CFM capacity, I can use a pair of mufflers with 400 CFM each. Much easier to design and definitely much quieter than a single 800 CFM muffler. That should make the biggest improvement.
If I get really frustrated and haven't managed that wholesale change by the end of the next racing season, I may go a temporary route and hang a couple of mufflers off the headers. Get the length right and with properly spec'd mufflers, it'll be as good as an open exhaust (or very close to). Ground clearance will suffer though.

Jorlain

iTrader: (4)

It's sort of a balancing act with these cars when you plan to street drive them at all. I wouldn't mind the black heart setup, but it's tough to justify the cost to myself. In the end I'll probably end up with a 3" exhaust. I'd like to just fab up my own 3.5" single, but I don't want to blindly buy a bunch of bends and hope I can make it work. Unfortunately, neither of my cars came with a full exhaust, so I don't have anything to compare and/or measure.

skinny z

There are/were aftermarket 3-1/2" and 4" over the axle packages available for these cars although I can't say if they're still produced or not. Unless you get imaginative, you still have to deal with a single muffler though. That's the biggest bottleneck.
The Black Heart system aside, I've thought that about the best arrangement for these cars as street cars is to buy a reasonable 3" single over the axle exhaust, single muffler and all and have cut-outs placed at the correct distance from the collectors. That's the hot ticket for a dual purpose car. At least when the ground clearance and chassis fitment are a problem as they are on third gens. Particularly lowered ones.

billybob6110

I have bullets do u get a lot of resonance in car? I do around 55mph have same setup as yours but 3 inch mufflers

pancherj

Single 3" into a dynomax muffler on my car with a "worked over" mufflex y-pipe. At our power level (I was running high 11's...gunning for low 11's now), the single 3" isn't hurting too much.

skinny z

Which Dynomax muffler is that?

pancherj

Ultra-Flo I believe. It has a single inlet and outlet. It has been on there since 2000 or so.

skinny z

The reason I ask is because I'm also running a single 3" muffler although in this case it's the last in line Flowmaster. It's possibly 300 CFM and that absolutely kills performance. I had thought about one of the race mufflers from the likes of Borla but those things are loud.
The best move I think in my case is to go either with something like Holley's new duals or keep the single 3" but add cutouts near the collectors.

pancherj

I'm guessing mine must flow pretty well. I once unhooked right behind the Y Pipe at the strip and it made no difference in my ET. It isn't loud at all with the muffler in place.


I agree with you though...your system may be hindering your performance a good bit.