Is 300hp possible with these mods?
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Joined: May 2010
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From: Morgans Point Resort Texas
Is 300hp possible with these mods?
1987 vert. 4+3 96k
Present Mods: Flowmaster cat back, open lid on breather.
Goals: To build a nice responsive street car.
HP Goal: 300
Budget: $1500
Proposed Mods:
Hedman Elite headers #68448
Remove precats and replace with hooker y pipe 3”
Replace cat with 3” in/out (already have flowmaster cat back)
Remove EGR, and air pump plumbing
Install SLP intake tubes, port/match factory plenum
delete slp
Add HSR
Install 1.6 roller tip rockers
Do TB bypass
Install adjustable fuel pump regulator
Possible options:
MAF mod
New injectors
Port match factory intake base
Present Mods: Flowmaster cat back, open lid on breather.
Goals: To build a nice responsive street car.
HP Goal: 300
Budget: $1500
Proposed Mods:
Hedman Elite headers #68448
Remove precats and replace with hooker y pipe 3”
Replace cat with 3” in/out (already have flowmaster cat back)
Remove EGR, and air pump plumbing
Install SLP intake tubes, port/match factory plenum
delete slp
Add HSR
Install 1.6 roller tip rockers
Do TB bypass
Install adjustable fuel pump regulator
Possible options:
MAF mod
New injectors
Port match factory intake base
Last edited by 1stvet87; Aug 5, 2010 at 02:18 PM. Reason: add/delete
Le Mans Master
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From: Houston Texas
Le Mans Master
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From: One day you're a Comet...the next day you're dust... Arkansas
1987 vert. 4+3 96k
Present Mods: Flowmaster cat back, open lid on breather.
Goals: To build a nice responsive street car.
HP Goal: 300
Budget: $1500
Proposed Mods:
Hedman Elite headers #68448
Remove precats and replace with hooker y pipe 3”
Replace cat with 3” in/out (already have flowmaster cat back)
Remove EGR, and air pump plumbing
Install SLP intake tubes, port/match factory plenum
Install 1.6 roller tip rockers
Do TB bypass
Install adjustable fuel pump regulator
Possible options:
MAF mod
New injectors
Port match factory intake base
Present Mods: Flowmaster cat back, open lid on breather.
Goals: To build a nice responsive street car.
HP Goal: 300
Budget: $1500
Proposed Mods:
Hedman Elite headers #68448
Remove precats and replace with hooker y pipe 3”
Replace cat with 3” in/out (already have flowmaster cat back)
Remove EGR, and air pump plumbing
Install SLP intake tubes, port/match factory plenum
Install 1.6 roller tip rockers
Do TB bypass
Install adjustable fuel pump regulator
Possible options:
MAF mod
New injectors
Port match factory intake base
Le Mans Master
Joined: Oct 2008
Posts: 9,758
Likes: 49
From: Houston Texas
Team Owner
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Thread Starter
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Joined: May 2010
Posts: 89
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From: Morgans Point Resort Texas
I understand things like TB bypass does not add HP. But are you saying that with upgraded exhaust, 1.6 rockers, and SLP runners, not to mention any porting that somewhere near 300 is not achievable. If so would i just be releasing some of the factory 240hp that is not being utilized. Either way improved performance is the primary goal.
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From: Morgans Point Resort Texas
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1987 vert. 4+3 96k
Present Mods: Flowmaster cat back, open lid on breather.
Goals: To build a nice responsive street car.
HP Goal: 300
Budget: $1500
Proposed Mods:
Hedman Elite headers #68448
Remove precats and replace with hooker y pipe 3”
Replace cat with 3” in/out (already have flowmaster cat back)
Remove EGR, and air pump plumbing
Install SLP intake tubes, port/match factory plenum
Install 1.6 roller tip rockers
Do TB bypass
Install adjustable fuel pump regulator
Possible options:
MAF mod
New injectors
Port match factory intake base
Present Mods: Flowmaster cat back, open lid on breather.
Goals: To build a nice responsive street car.
HP Goal: 300
Budget: $1500
Proposed Mods:
Hedman Elite headers #68448
Remove precats and replace with hooker y pipe 3”
Replace cat with 3” in/out (already have flowmaster cat back)
Remove EGR, and air pump plumbing
Install SLP intake tubes, port/match factory plenum
Install 1.6 roller tip rockers
Do TB bypass
Install adjustable fuel pump regulator
Possible options:
MAF mod
New injectors
Port match factory intake base
I wouldn't do 3" pipe or the MAF mod with your config.
Le Mans Master
Joined: Jun 2006
Posts: 5,642
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From: One day you're a Comet...the next day you're dust... Arkansas
I understand things like TB bypass does not add HP. But are you saying that with upgraded exhaust, 1.6 rockers, and SLP runners, not to mention any porting that somewhere near 300 is not achievable. If so would i just be releasing some of the factory 240hp that is not being utilized. Either way improved performance is the primary goal.
However, the car will be peppier and sound better. They are still worth doing.
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From: Morgans Point Resort Texas
Did you put a 3" cat-back on a stock car? What's your future goals. What's listed about is worth an optimistic 35hp IMO. But the AFPR is the one mod I find controversial. Vader's site show this mod as making some fairly significant gains. They were enough I had to wonder if the test car had a problem getting to 12.5 AFR w/o the mod.
I wouldn't do 3" pipe or the MAF mod with your config.
I wouldn't do 3" pipe or the MAF mod with your config.
I also have read many opinions on the afpr's adding more hp. Not sure i would agree, but making sure adequate pressure is supplied to injectors so that proper spray patterns are acheived seems logical.
As far as future goals, I doubt i will go beyond the mods i have listed.
Le Mans Master
Joined: Oct 2008
Posts: 9,758
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From: Houston Texas
The cat back system was already on there when i bought it. Haven't measured pipe to be honest but it looks like a 3" just past the cat. Doing research i believe it to be the flowmaster i believe it was called force II. recommended for torque.
I also have read many opinions on the afpr's adding more hp. Not sure i would agree, but making sure adequate pressure is supplied to injectors so that proper spray patterns are acheived seems logical.
As far as future goals, I doubt i will go beyond the mods i have listed.
I also have read many opinions on the afpr's adding more hp. Not sure i would agree, but making sure adequate pressure is supplied to injectors so that proper spray patterns are acheived seems logical.
As far as future goals, I doubt i will go beyond the mods i have listed.
Le Mans Master
Joined: Oct 2008
Posts: 9,758
Likes: 49
From: Houston Texas
Team Owner
Joined: Aug 2005
Posts: 34,988
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From: Riverside County Southern California
Co-winner 2020 C4 of the Year - Modified
2018 Corvette of Year Finalist
2017 C4 of Year
2016 C7 of Year Finalist
St. Jude Donor '09 thru '20
Good point but you can buy the LT1 and with those mods you'll get more HP out of it. 
If you have a busget of $1,500 it means you can go $5,000. How do I know?
I had no money when I bought my LT4 Vette and magically I rebuilt and fixed the whole thing.
Money is there, get a loan, get a new credit card. Live now, December 21, 2012 is coming 
.
Thread Starter
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Joined: May 2010
Posts: 89
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From: Morgans Point Resort Texas
Morgans Point Resort is just off 35 outside of Temple/Belton. There is also a Morgans Point somewhere near coast, Galveston area. I used to live and work in your area. Remember Lawrence Marshall Chevrolet in Hempstead.
Thread Starter
Advanced
Joined: May 2010
Posts: 89
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From: Morgans Point Resort Texas
Good point but you can buy the LT1 and with those mods you'll get more HP out of it. If you have a busget of $1,500 it means you can go $5,000. How do I know?
I had no money when I bought my LT4 Vette and magically I rebuilt and fixed the whole thing.
Money is there, get a loan, get a new credit card. Live now, December 21, 2012 is coming .
Le Mans Master
Joined: Jun 2006
Posts: 5,642
Likes: 5
From: One day you're a Comet...the next day you're dust... Arkansas
Good point but you can buy the LT1 and with those mods you'll get more HP out of it. If you have a busget of $1,500 it means you can go $5,000. How do I know?
I had no money when I bought my LT4 Vette and magically I rebuilt and fixed the whole thing.
Money is there, get a loan, get a new credit card. Live now, December 21, 2012 is coming .