[dreeve]

i just did a top end rebuild on my lt1 and would like to have a estimate of hp im pushing. so here are the mods ive put on..

-ram air intake
-edelbrock intake manifold
-bbk 52 mm throttle body
-accel 30lb injectors
-scorpion 1.6 roller rockers
-erson .480 lift cam
-ported/polished stock heads
-lunati lifters
-msd coil,opti cover,wires
-bosch +4 plugs
-dougs shorty headers
-magnaflow highflow cat
-cherry bomb muffler
-whole block was cleaned up, new bearings, seals, etc.

thanks a bunch!! -dennis

 

[Viper]

Without duration and lsa on cam difficult to estimate. Also the porting work is unknown.
T56 or 4L60e transmission?

Good stock engine 245-255HP at wheels depends on transmission.
shorty header high flow cat +15hp
52 T body +5hp
If higher compression est +5hp
Working ram air intake +10hp
Ported heads +20hp
Edelbrock intake is a wash stock ported runs faster.
Assuming mild daily driver cam with .480 Lift +25HP
1.6 Rockers +8hp Lift at .513 great for stock heads

With automatic transmission estimate ~ 330rwhp Manual 340rwhp

Performance use differential gear ratio 3.73

Stall convertor 2400 2800 3400 3800 RPM

Depends on state of tune and density altitude could run 13.10et to high 12's
Faster with slicks street compound and suspension mods.

 

[KW Baraka]

Need intake and exhaust duration as well as the lobe seperation angle for the cam.

Need compression ratio.

Need to know the extent of head porting and whether stock or aftermarket (size) valves are used.

Need to know if the PCM was tuned.

BTW......Edlebrock Intake = magnificent waste of money .

With automatic transmission estimate ~ 330rwhp Manual 340rwhp.....

Highly unlikely; especially if that Erson cam is as dinky as I believe it is.....

KW

 

[dreeve]

intake duration- 222.0
exhaust duration- 226.0
lobe angle- 116+8
valve intake- 1.94
valve exhaust- 1.50

i had the pcm custom tuned from pcmforless,it has stock compression, i am about to install a monster 700r4 tranny with a 2500-2800 stall, 373's are not far behind that,im getting the feeling i should throw a heftier cam in with a set of trickflow heads. any other info you may need let me know! this is greatly appreciated, also just curious but what is the reason for the edelbrock intake not having a better flow than stock?

 

[Viper]

That cam is similar in Duration to GM846 Performance close to CC503 but 116lsa with auto trans I'd say 345-355 rwhp with everything tweaked to perfection.


Suggest a 110LSA or 112LSA cam 221-224 intake duration 227-230 exhaust duration with ported heads .550 intake and .560 exhaust with 1.6 rocker arms .520 intake .530 with 1.5's .


If really want more power and rev to 6500rpm 230I/236E duration at .050 and .550/.560 Lift with 1.6 Rocker arms 110lsa.

I'd try changing the cam 1st to see if the ported stock heads are good enough. If still want MORE then change to the Trick Flows.

The cam you have now should have good mid range fair top end. Try the convertor and 3.73 gears 1st it will make a different car by getting the engine s current combination up into its powerband shift around 6200-6300RPM in tune.

Also if your 93z28 is an original T-top there are very few of them.

 

[dreeve]

thanks alot man i just learned alot! not to familiar with cam sizes and durations etc. so kinda toyin around with that, i figured if im going to go through the hassel of changing the cam again i might as well get the whole trick flow kit, and i will more than likely make it a 383 im thinking the gears are holding me back the most right now, if im correct it has 272's...thats just ridiculous, but yes it is all original, i believe there was just over 2,000 of them made. i know i will have that car the rest of my life for sure!

 

[95whitetransam]

Those shorty headers are really going to hold you back. Get some long tubes and off road y pipe and you'll pick up a nice little gain.

 

[Viper]

Information on the 93Z28's that differs from other year Z28's post #8

http://www.ls1lt1.com/forum/lt1-|-lt4-|-l99-engine-tech/58848-got-me-new-toy.html#post485347

 

[Viper]

Edelbrock parts heads cam and intake do not make very good power for LT1's they were and are excellent in other varieties and generations of Gm Small Block Chevy's.

The factory GM LT1 intake only differs from the LT4 intake in the height of the runners internal dimensions and flow is similar. The factory intake is similar to a large open plenum short runner tunnel ram It works better at mid and high rpm. Older tuned port engines had small plenum long runners good for low rpm torque. Newer LS1 engines have a hybrid long runner and large open plenum good across the powerband.

Ported or unported the factory manifold flows 250-275cfm this is much more than stock heads and as good as most all ported heads flow. In a trick 355 you'd have to make 450+HP to utilize the flow. The Edelbrock flows more but velocity is slower making less power down low etc. For a race only engine The Edelbrock LT1/LT4 RPM air gap might help but they usually cut the top off of the stock one port them and re weld or mfg bolt on panel some make custom sheet metal intakes or run LT1 carbureted race single plane manifolds.

Edelbrock RPM Air Gap LT1 Intake Manifold Testing - GM High-Tech Performance

LT1 Intake. - Hot Rod Forum : Hotrodders Bulletin Board

GM High-Tech Perf tests the Edelbrock LT1 intake - CamaroZ28.Com Message Board

Edelbrock LT1 Performance Package - Engine Masters Magazine

Flow numbers for DIY intake vs stock, & LE2 head - CamaroZ28.Com Message Board

 

[Viper]

Gear calculator that shows difference between 2.73 and 3.23 gear ratios can also enter 3.73s see mph shift point differences.

http://radd.zeroproof.com/gears.htm

 

[dreeve]

thats crazy how little hp gain there is from the intake, kinda makes me sick i paid that much money for it