Guestimate my HP
Thread Starter
Supreme Member
Joined: Jan 2007
Posts: 1,002
Likes: 12
From: Bastrop, TX
Car: 1988 SC Convertible
Engine: LT-1
Transmission: 700R4
Axle/Gears: 3.23 posi w/PBR's
Guestimate my HP
I ditched the 200K + LO3 several months ago in favor of a low mileage 355 that I got from one of my local club members. I drove the car about 200 miles before I started stripping it down for paint. I just started driving the car again about a week or so ago when I finished making it shiny.
I have no idea what kind HP/TQ #'s I'm putting down with this combo and who knows when I'll get a chance to get it on a dyno. All I know is my car is WAY quicker now than it was with the 305.
Here's what I have in it now:
350 block from '96 Chevy truck
Bored .030 over
9.8:1 compression.
Hypereutectic pistons.
HD rods.
LO3 heads ported and polished, 3 angle valve job, machined surface, cut pockets.
Competition Cam, 211/221 @ .050 with .442/.465 lift 110 LSA.
Port and gasket matched intake/heads
Stock TBI with 350 injectors.
180* stat.
Accel coil.
Accel plugs
8mm Accel wires
Edelbrock shorties with custom Y-pipe
Mail order chip
I've done all of the Ultimate TBI mods and run an open element.
I swapped in a T-5 and my ratios are:
Ratio........1st.............2nd.........3rd.........4th............Rev.......5th
T5U..........2.95...........1.94.......1.34........1.1............2.76........63
I have a 3.27 9 bolt from an 89 GTA.
The car pulls extremely hard up to 5K RPM...I don't really push it much past that driving around.
Does anybody know what this combo should realistically put down?
For the record, after swapping this in I have killed two different 4th gen LS1 cars from stoplights up to 100 MPH. (Not in the city...we have a stoplight out in the middle of a 4 lane highway for some strange reason.)
I have no idea what kind HP/TQ #'s I'm putting down with this combo and who knows when I'll get a chance to get it on a dyno. All I know is my car is WAY quicker now than it was with the 305.
Here's what I have in it now:
350 block from '96 Chevy truck
Bored .030 over
9.8:1 compression.
Hypereutectic pistons.
HD rods.
LO3 heads ported and polished, 3 angle valve job, machined surface, cut pockets.
Competition Cam, 211/221 @ .050 with .442/.465 lift 110 LSA.
Port and gasket matched intake/heads
Stock TBI with 350 injectors.
180* stat.
Accel coil.
Accel plugs
8mm Accel wires
Edelbrock shorties with custom Y-pipe
Mail order chip
I've done all of the Ultimate TBI mods and run an open element.
I swapped in a T-5 and my ratios are:
Ratio........1st.............2nd.........3rd.........4th............Rev.......5th
T5U..........2.95...........1.94.......1.34........1.1............2.76........63
I have a 3.27 9 bolt from an 89 GTA.
The car pulls extremely hard up to 5K RPM...I don't really push it much past that driving around.
Does anybody know what this combo should realistically put down?
For the record, after swapping this in I have killed two different 4th gen LS1 cars from stoplights up to 100 MPH. (Not in the city...we have a stoplight out in the middle of a 4 lane highway for some strange reason.)
Member
Joined: Oct 2005
Posts: 330
Likes: 0
From: Dyer, In
Car: 91 Camaro RS
Engine: 355 Vortec
Transmission: 700r4
Axle/Gears: 3.42
Re: Guestimate my HP
I would say it is not possible to give a reasonable hp estimate without knowing flow date for the heads. However, with the cam you are running it would take a heck of a port job on LO3 heads with stock valve size to get into stock LS1 territory.
Member
Joined: Oct 2005
Posts: 330
Likes: 0
From: Dyer, In
Car: 91 Camaro RS
Engine: 355 Vortec
Transmission: 700r4
Axle/Gears: 3.42
Re: Guestimate my HP
216hp
Thread Starter
Supreme Member
Joined: Jan 2007
Posts: 1,002
Likes: 12
From: Bastrop, TX
Car: 1988 SC Convertible
Engine: LT-1
Transmission: 700R4
Axle/Gears: 3.23 posi w/PBR's
Re: Guestimate my HP
It's a 350 now, not a 305.
I was wondering when I would get the "LO3 heads are boat anchors"
.As I mentioned in my first post I have done all of the Ultimate TBI mods in the sticky. (grinding down the TB, bumping FP, injector spacer, etc....)
I have an LO5 intake.
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Re: Guestimate my HP
Ha, Ha!!!!
It's a 350 now, not a 305.
I was wondering when I would get the "LO3 heads are boat anchors"
.
As I mentioned in my first post I have done all of the Ultimate TBI mods in the sticky. (grinding down the TB, bumping FP, injector spacer, etc....)
I have an LO5 intake.
It's a 350 now, not a 305.
I was wondering when I would get the "LO3 heads are boat anchors"
.As I mentioned in my first post I have done all of the Ultimate TBI mods in the sticky. (grinding down the TB, bumping FP, injector spacer, etc....)
I have an LO5 intake.
Supreme Member
Joined: Jun 2006
Posts: 2,199
Likes: 1
From: West-Central
Car: 91 Trans am
Engine: built 360 TBI
Transmission: built 700r4
Axle/Gears: 10bolt/3.23
Re: Guestimate my HP
I think this could be close.
https://www.thirdgen.org/forums/post...84-post22.html
https://www.thirdgen.org/forums/post...84-post22.html
Joined: Sep 2005
Posts: 1,125
Likes: 55
From: PA
Car: 92 camaro RS
Engine: LSA
Transmission: Magnum F
Axle/Gears: TNT 8.8 wavetrac 3.31
Re: Guestimate my HP
what kinda h.p you putin down alvanwie?
Member
Joined: Oct 2005
Posts: 330
Likes: 0
From: Dyer, In
Car: 91 Camaro RS
Engine: 355 Vortec
Transmission: 700r4
Axle/Gears: 3.42
Re: Guestimate my HP
Reply to "obeymybird":
Never been on a dyno or the track, but Dyno2003 says it should be capable of 400 fwhp.
Never been on a dyno or the track, but Dyno2003 says it should be capable of 400 fwhp.
Last edited by alvanwie; Nov 3, 2009 at 01:56 PM. Reason: This was a reply to "obeymybird"s question
Joined: Feb 2001
Posts: 13,756
Likes: 560
From: Cincinnati, OH
Car: '90 RS
Engine: 377 LSX
Transmission: Magnum T56
Re: Guestimate my HP
A stock valved and unported LO3 head will flow around 165cfm which is good for a theoretical power limit just north of 300. Porting will expand that range but I am not sure if you are near 400hp. I would suspect your car could be a lot faster with some DIY chip tuning. That mail order tune is leaving a lot of power. My geuss is that you are making around 300hp with the capability of making near 340 or so with a better tune and possibly larger TBI unit.
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iTrader: (12)
Joined: Jul 1999
Posts: 12,212
Likes: 13
From: Bertram (outside Austin), TX
Car: 87 GTA
Engine: L98
Transmission: 700R4
Axle/Gears: Dana M78 3.27 posi
Joined: Jan 2007
Posts: 283
Likes: 0
From: Minnesota
Car: 1969 firebird, 1986 Trans Am,
Engine: 461,305TB
Transmission: T-10,700r4
Axle/Gears: 3.55,2.73
Re: Guestimate my HP
IMHO in a street race allot of things can happen, around here ls1 cars run and dyno pretty strong.
For horsepower I always go more by trap speeds at the strip than dyno's. They seem to be more even track to track compared to dyno to dyno. You may be surprised how some cars ET pretty strong with supposed small rwhp numbers.
I always gotta know my "numbers" but it sounds strong. A third with some power is a fun car to drive!
For horsepower I always go more by trap speeds at the strip than dyno's. They seem to be more even track to track compared to dyno to dyno. You may be surprised how some cars ET pretty strong with supposed small rwhp numbers.
I always gotta know my "numbers" but it sounds strong. A third with some power is a fun car to drive!
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iTrader: (12)
Joined: Jul 1999
Posts: 12,212
Likes: 13
From: Bertram (outside Austin), TX
Car: 87 GTA
Engine: L98
Transmission: 700R4
Axle/Gears: Dana M78 3.27 posi
Member
Joined: Apr 2009
Posts: 162
Likes: 0
From: San Antonio
Car: 1990 RS
Engine: 305 TBI
Transmission: T-5
Axle/Gears: 3.08
Re: Guestimate my HP
Its been proven to be within +/- 10hp several times. If you know how to use it.
As for this engine it shows peak (at the flywheel)
tq 422 @ 3500rpm
hp 388 @ 5500rpm
However, the stock tbi injectors, at stock pressure just won't pull those numbers.
My guess 230-240hp 330-360ft-lbs tq
As for this engine it shows peak (at the flywheel)
tq 422 @ 3500rpm
hp 388 @ 5500rpm
However, the stock tbi injectors, at stock pressure just won't pull those numbers.
My guess 230-240hp 330-360ft-lbs tq
Supreme Member
Joined: Jun 2006
Posts: 2,199
Likes: 1
From: West-Central
Car: 91 Trans am
Engine: built 360 TBI
Transmission: built 700r4
Axle/Gears: 10bolt/3.23
Re: Guestimate my HP
I think you should read the OP's post again, you must have done some confusion.
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