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HP Estimation

Old Nov 21, 2011 | 11:59 AM
  #1  
JLCustomizing's Avatar
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From: North Iowa
Car: 1984 Trans Am
Engine: 5.7 Liter V8
Transmission: Auto 700R4
Axle/Gears: Stock
HP Estimation

Im trying to estimate what horsepower I'm pushing so I know what I'll get overhead with a few add-ons. Heres my current setup

5.7 Liter engine bored .30 over (77 chevy block)
Keith Black Flat top pistons
305 Heads with 3 way valve job
Edelbrock Performer Plus Cam
Quadrajet 750 cfm Carb non ccc
Power Bludge Hood connected
700R4 Tranny
Stock 84 T/A gears
Stock Exhaust

I am going to put some headers and an upgraded exhaust this spring and maybe some nitrous. Im wondering what hp and whp Im pushing and what recommendations based on my setup people would have for exhaust and decent nitrous setups. I'm not looking for more then 100 shot of nitrous probably as I wont use it very often, just a fun track thing.
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Old Nov 21, 2011 | 12:30 PM
  #2  
torque_is_good's Avatar
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Re: HP Estimation

specs and flow numbers on heads...........

specs on camshaft...............

Or, I can simply say 400RWHP how does that sound?

I could also say 235 RWHP. Why does it matter?

Go to the track

what is your 60 foot

what is your trap speed

what is your et


those are the only numbers which really matter
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Old Nov 21, 2011 | 12:56 PM
  #3  
JLCustomizing's Avatar
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From: North Iowa
Car: 1984 Trans Am
Engine: 5.7 Liter V8
Transmission: Auto 700R4
Axle/Gears: Stock
Re: HP Estimation

Cam Specs:
Duration @ .50 Int/Exh 204/214

Life @ Valve Int/Exh
.420"/.442"

Lobe Seps
112

Idle Vacuum @ 1000 RPM
14"

As for the heads I'm not sure. I bought the car this way and was interested in what the horsepower number might be. The nearest track is almost 2 hours away so I can't run my numbers till spring when the snow clears up.
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Old Nov 22, 2011 | 04:44 PM
  #4  
gmstrong's Avatar
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From: williamstown,NJ
Car: 95 9C1,99 Sierra,90Sierra,00 sierra
Engine: TBI350,LM7,LT1,Vortec 350
Transmission: 700r4,4L60e,4L60e,4L80e
Axle/Gears: 10 bolt,14bolt,3:42,3:73,3:08,3:73.
Re: HP Estimation

I would say somewhere around 240-250 at the flywheel.
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Old Nov 22, 2011 | 11:54 PM
  #5  
JLCustomizing's Avatar
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From: North Iowa
Car: 1984 Trans Am
Engine: 5.7 Liter V8
Transmission: Auto 700R4
Axle/Gears: Stock
Re: HP Estimation

Hopefully I can drive those numbers up once I get some headers and a better exhaust going. Don't know why you'd drop all the cash on the engine and not let it breath right! I'm sure with this build it could handle a 100 shot of nitrous every once in awhile.
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Old Nov 23, 2011 | 04:59 AM
  #6  
89RsPower!'s Avatar
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From: New Jersey
Car: 86 Corvette, 89 IROC, 1999 TA
Engine: 350, 350, LS1
Transmission: 700r4, 700r4, T-56
Axle/Gears: 3.07, 373, 4.10
Re: HP Estimation

Things happen for weird reasons, I have the built tpi engine that was going to be the replacement for my corvette in my 89 cause the 305 started knocking, been running with complete stock exhaust, 305 prom, all emissions etc, basically it looks like a real pretty stock setup.. still way faster then the old LB9 but nothing like it really should be, still runs just fine for a dd and even made it through emissions..
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Old Nov 23, 2011 | 11:12 AM
  #7  
JLCustomizing's Avatar
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From: North Iowa
Car: 1984 Trans Am
Engine: 5.7 Liter V8
Transmission: Auto 700R4
Axle/Gears: Stock
Re: HP Estimation

Im lucky that I live in Iowa so they never check anything. I'm guessing if I got a set of long tube headers and changed it to an x-pipe or h-pipe exhaust I'd have pretty good luck. I don't want to go to crazy with the engine though as its my daily driver. If I can get it up to maybe 300hp at the flywheel id be pretty happy.
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Old Nov 23, 2011 | 01:46 PM
  #8  
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Re: HP Estimation

I would say right round 290 but if you ditched the 305 heads and got the exhaust flowing I bet you would pick up a fairly large amount of power. Not hating at all as i to have 305 heads on my 350 bored over. But I will say 305 heads deserve to be on a 305 or at the bottom of the ocean haha
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Old Nov 23, 2011 | 01:57 PM
  #9  
JLCustomizing's Avatar
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From: North Iowa
Car: 1984 Trans Am
Engine: 5.7 Liter V8
Transmission: Auto 700R4
Axle/Gears: Stock
Re: HP Estimation

Any head recomendations? I've been considering swapping around heads actually. All 305 headers will bolt right onto a 350 also correct?
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Old Nov 23, 2011 | 02:07 PM
  #10  
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Re: HP Estimation

yup same block just different bore sizes. 305,327,350,400 all look identical on outside. As far as heads I would try to stay around 60-62cc since your 305 heads are like 59cc. That is unless the compression is to high for you as it is then jump up to 64 or higher. I am thinking of getting some RHS assembled heads from Summit if your on a budget you could look into them to. This is the other set I am considering and there aluminum http://www.summitracing.com/parts/EDL-60859/ Both good options IMO

Last edited by 240zboy; Nov 23, 2011 at 02:17 PM.
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Old Nov 23, 2011 | 02:19 PM
  #11  
88gta3508's Avatar
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Posts: 581
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From: NY
Car: 00 SSEi / 94 C4
Engine: 231 / 383
Transmission: 4T65E / ZF 6sp
Axle/Gears: 2.93 / Dana 44 3:45
Re: HP Estimation

The 1.88 valves are going to constrict your flow
That cam and 305 heads and stock valves I don't think you will even make it to 270 HP
The complete edlebrock kit heads, cam, intake is only rated for 315 HP
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Old Nov 23, 2011 | 02:44 PM
  #12  
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Re: HP Estimation

yea there is no real way to tell until you hit the track but your motor will definately have more umph then a stocker but I would say those heads need to go if you want to see your motors potential. Next get that stock exhaust and headers out of there and then I personally would get rid of the quadrajet.
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Old Nov 23, 2011 | 03:31 PM
  #13  
88gta3508's Avatar
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Posts: 581
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From: NY
Car: 00 SSEi / 94 C4
Engine: 231 / 383
Transmission: 4T65E / ZF 6sp
Axle/Gears: 2.93 / Dana 44 3:45
Re: HP Estimation

Mandatory headers and exhaust to let the engine exhale...
Keep the Q-jet most people can't take them apart... They get better milage over holley's
You can do some tricks... And jet They make the same power as a proper tuned holley
The biggest problem with holley designs... the average person has no clue!!! where to start there is way to many adjustment... And make them run way to rich.. takes them to long to figure out
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Old Nov 23, 2011 | 06:12 PM
  #14  
freaky's Avatar
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Posts: 1,074
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From: VA
Car: 88 camaro irocz
Engine: l98 tpi
Transmission: 700r4
Axle/Gears: 2.77
Re: HP Estimation

vortec heads with 1.94 / 1.50 valves seem to be best bang for your buck .
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