RWHP question
Thread Starter
Instructor
Joined: May 2000
Posts: 137
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From: Boise Idaho
RWHP question
I had just gotten my 98 vette dyno tuned after putting on some mods and I was a little disappointed with the gains. Here is what I have on my vette:
dual cone air intake, vram velocity stack, LG long tube street series headers w/o cats and borla stingers.
With the tune I am putting down 321RWHP and 336ft/lbs of torque.
I didn't get dyno before the mods so I am not sure what I was putting down before. The tune guy said that my limiting factors are my air intake manifold and air bridge. He recommended upgrading to the F.A.S.T intake manifold (using the stock throttle body) and a new air bridge and smooth coupler. I have a couple questions. Would it be fine to just go with the stock size 78mm F.A.S.T intake manifold with the air bridge or do I need to buy the F.A.S.T throttle body too (like the 90mm)? And, do the numbers I am putting down sound about right with the mods I have?
Additionally, if my future plans include upgrading my heads/cam, would I see any significant benefit in upgrading to the 90mm throttle body?
Your input would be greatly appreciated!
dual cone air intake, vram velocity stack, LG long tube street series headers w/o cats and borla stingers.
With the tune I am putting down 321RWHP and 336ft/lbs of torque.
I didn't get dyno before the mods so I am not sure what I was putting down before. The tune guy said that my limiting factors are my air intake manifold and air bridge. He recommended upgrading to the F.A.S.T intake manifold (using the stock throttle body) and a new air bridge and smooth coupler. I have a couple questions. Would it be fine to just go with the stock size 78mm F.A.S.T intake manifold with the air bridge or do I need to buy the F.A.S.T throttle body too (like the 90mm)? And, do the numbers I am putting down sound about right with the mods I have?
Additionally, if my future plans include upgrading my heads/cam, would I see any significant benefit in upgrading to the 90mm throttle body?
Your input would be greatly appreciated!
Race Director
Joined: Apr 2005
Posts: 10,179
Likes: 2,306
From: Wesley Chapel, FL Las Vegas, NV
Here is what I have on my vette:
dual cone air intake, vram velocity stack, LG long tube street series headers w/o cats and borla stingers.
With the tune I am putting down 321RWHP and 336ft/lbs of torque.
dual cone air intake, vram velocity stack, LG long tube street series headers w/o cats and borla stingers.
With the tune I am putting down 321RWHP and 336ft/lbs of torque.
I would suggest picking up a LS6 Intake. (approx. $325 for a like new used) The FAST is way too expensive for what you get.
The Stock Throttle Body is OK. (I'm still on a stock throttle body with my setup.)
A smooth Airbridge will help but very little.
Race Director
Joined: Jun 2004
Posts: 19,459
Likes: 48
From: Schaumburg IL
CI 7-8-9-11 Veteran
St. Jude Donor '06-'10, '13
Stock you were probably 290 -300 so your numbers are right on for the mods you have.
I would suggest picking up a LS6 Intake. (approx. $325 for a like new used) The FAST is way too expensive for what you get.
The Stock Throttle Body is OK. (I'm still on a stock throttle body with my setup.)
A smooth Airbridge will help but very little.
I would suggest picking up a LS6 Intake. (approx. $325 for a like new used) The FAST is way too expensive for what you get.
The Stock Throttle Body is OK. (I'm still on a stock throttle body with my setup.)
A smooth Airbridge will help but very little.
Don't waste your money on a fast intake, unless you are going with a bigger cam, and changing heads...even then the FastIntake will get you about 20HP give or take...
I am running Heads/cam and still have the LS6Intake...for me the $800+ was not worth 20 or so HP people have shown by adding the Fast. Also leave the stock throttle body too, again unless you are planning on doing head work and swapping cams.
For the mods you have, your numbers seem fine.
Safety Car
Joined: Oct 2000
Posts: 4,949
Likes: 10
From: Monticello MN
Stock you were probably 290 -300 so your numbers are right on for the mods you have.
I would suggest picking up a LS6 Intake. (approx. $325 for a like new used) The FAST is way too expensive for what you get.
The Stock Throttle Body is OK. (I'm still on a stock throttle body with my setup.)
A smooth Airbridge will help but very little.
I would suggest picking up a LS6 Intake. (approx. $325 for a like new used) The FAST is way too expensive for what you get.
The Stock Throttle Body is OK. (I'm still on a stock throttle body with my setup.)
A smooth Airbridge will help but very little.
Ed
Pro
Joined: Jun 2007
Posts: 713
Likes: 9
From: Saratoga Springs Ut
I agree with not going with the FAST intake unless you are going with a huge cam and ported heads. The LS6 intake will be enough and just port and polish your stock TB. A nice H/C package will give you the best gains.
Drifting
Joined: Sep 2005
Posts: 1,258
Likes: 0
From: Home Southern Maine
St. Jude Donor '08
I dont think the FAST/90 is needed unless you are going with a big cam, try an LS6 intake. Swap the velocity stack for a stock ported TB.
For comparision purposes, here is my car with AR LT headers/Cats/Xpipe/Borla Stingers, LS6 Intake, Stock Ported TB, EFI Live Self tune (Weeks of logging and tweaking) with stock Airbridge and stock connector to TB.
Added patriot stage two heads and a mild comp cams 224/228 114 with a powerbond pulley
For comparision purposes, here is my car with AR LT headers/Cats/Xpipe/Borla Stingers, LS6 Intake, Stock Ported TB, EFI Live Self tune (Weeks of logging and tweaking) with stock Airbridge and stock connector to TB.
Added patriot stage two heads and a mild comp cams 224/228 114 with a powerbond pulley
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Burning Brakes
Joined: Jun 2007
Posts: 1,043
Likes: 3
From: Roselle IL
Hi,
I had my Dyno Tune done and got 321 hp and 319 tq.
1998 A-4 Mods:
3.42 gears, 3200 stall, Vararam, FLP Longtube Headers,
I thought the numbers were low too, mostly the torque, but everyone here said there were right on.
I had my Dyno Tune done and got 321 hp and 319 tq.
1998 A-4 Mods:
3.42 gears, 3200 stall, Vararam, FLP Longtube Headers,
I thought the numbers were low too, mostly the torque, but everyone here said there were right on.
Racer
Joined: Jan 2003
Posts: 471
Likes: 0
From: Monterey Area CA
My '03 with Hurricane intake, new plugs, Kooks Longtube, stock cats, and Borla Stingers, tuned made high 300s see below. Every car is slightly different - plus I think there was some changes between my year and some previous years that accounts for some difference too.
The highest numbers were thanks to TTi X.
The highest numbers were thanks to TTi X.
Le Mans Master
Joined: Feb 2007
Posts: 9,296
Likes: 1,531
From: Oviedo Florida
2024 C5 of the Year Finalist - Modified
2024 C2 of the Year Finalist - Modified
2023 C2 of the Year Finalist - Modified
2021 C2 of the Year Finalist - Modified
2016 C5 of Year Finalist
Your right there brother now you need to pull more air in the
top side LS6 intake ,bridge and smooth out the air flow.
And your headen in the right direction.
top side LS6 intake ,bridge and smooth out the air flow.
And your headen in the right direction.
Burning Brakes
Joined: Jun 2005
Posts: 860
Likes: 0
From: Jacksonville Florida
My '98 A4 with K&N FIPK and Ti exhaust netted a little over 300/300....something like 302/304 if I remember correctly. Another 20+ rwhp from longtubes and a tune isn't out of this world but definitely within what you'd expect.
There might be a few more horsepower found in a different tune, but an LS6 intake is a good option for you at this point. Taking into account the cost of the parts and labor I think that's your most cost effective dollar for horsepower option at this point.
There might be a few more horsepower found in a different tune, but an LS6 intake is a good option for you at this point. Taking into account the cost of the parts and labor I think that's your most cost effective dollar for horsepower option at this point.
Race Director
Joined: Apr 2005
Posts: 10,179
Likes: 2,306
From: Wesley Chapel, FL Las Vegas, NV
My '03 with Hurricane intake, new plugs, Kooks Longtube, stock cats, and Borla Stingers, tuned made high 300s see below. Every car is slightly different - plus I think there was some changes between my year and some previous years that accounts for some difference too.
The highest numbers were thanks to TTi X.
The highest numbers were thanks to TTi X.
Melting Slicks
Joined: May 2005
Posts: 2,866
Likes: 123
From: gresham oregon
The twin turbos sure made a huge difference in the dyno numbers. 
Race Director
Joined: Jan 2003
Posts: 19,802
Likes: 0
From: San Antonio Texas
St. Jude Donor '05-'06-'08
