HCI LS1 Trans Am Dyno
Thread Starter
Launching!
Joined: Mar 2012
Posts: 216
Likes: 25
From: Enid, Oklahoma
HCI LS1 Trans Am Dyno Finally got my car finished and is headed to the dyno on wednesday morning. Anyone want to make some guesses as to what it makes? I'm hoping for 450 rwhp or close to it ... I'll post up the dyno sheet sometime wednesday afternoon!
1998 Trans Am SBE LS1 36k miles
PRC 225 As Cast 62cc chambers
Custom BTR 231/243 112+3
Vengeance Ported FAST 92/NW 92
SE 1 7/8 headers, ORY, SLP LM1
Monster LT1-S Twin Disc
FAST 36lb Injectors
Racetronix 255 Fuel pump hot wired
Will be SD tuned so no MAF
1998 Trans Am SBE LS1 36k miles
PRC 225 As Cast 62cc chambers
Custom BTR 231/243 112+3
Vengeance Ported FAST 92/NW 92
SE 1 7/8 headers, ORY, SLP LM1
Monster LT1-S Twin Disc
FAST 36lb Injectors
Racetronix 255 Fuel pump hot wired
Will be SD tuned so no MAF
Thread Starter
Launching!
Joined: Mar 2012
Posts: 216
Likes: 25
From: Enid, Oklahoma
Yes for now, i do have a flowmaster merge and a 4'' cutout sitting in a box that i didnt have time to get installed before the dyno tune. I was really wanting to get it installed because i know there will be decent gains to be had from the merge and cutout
Good deal. Either way will be sitting on some good power.
I would want to touch up the tune after the 4" install, so you may want to install it first if it is gonna cost you to have the tune checked after it's put on
You're gonna see a decent gain from going from a 3" y pipe to a 4" so the tune will need to be looked at
But with it all done including the 4" I bet you're over 460
You're gonna see a decent gain from going from a 3" y pipe to a 4" so the tune will need to be looked at
But with it all done including the 4" I bet you're over 460
Thread Starter
Launching!
Joined: Mar 2012
Posts: 216
Likes: 25
From: Enid, Oklahoma
I would want to touch up the tune after the 4" install, so you may want to install it first if it is gonna cost you to have the tune checked after it's put on
You're gonna see a decent gain from going from a 3" y pipe to a 4" so the tune will need to be looked at
But with it all done including the 4" I bet you're over 460
You're gonna see a decent gain from going from a 3" y pipe to a 4" so the tune will need to be looked at
But with it all done including the 4" I bet you're over 460
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I wouldn't be surprised if you see up to 20 hp or so with the 4" vs the single 3" exhaust on a near 600 flywheel horsepower engine
Check out the first post in this thread. Seems a little high on the increase in power but I can't find many other dynos back to back to compare single 3" to dual 3" or single 3" vs 4" so take it as you will
https://www.performancetrucks.net/fo...totype-538474/
I'm not saying anything is gonna happen if you don't tune it after you upgrade the exhaust. But I would want the tune optimized with the freer flowing exhaust. And the tune may need a small adjustment with the higher flowing setup to be spot on.
My current truck picked up very considerable power after the tune when I put headers on it. My F body car picked up considerable power when I did headers and exhaust and the tune didn't make much of a difference. Not sure what the deal was there but my truck didn't seem to be any faster after the headers and exhaust, but after it was re tuned with the headers and exhaust it was a huge difference. The truck was already tuned before the headers. So going forward I'm going to always want a tune touch up after even a small exhaust change. Which makes since anyway since it flows more even if it's just a little.
Check out the first post in this thread. Seems a little high on the increase in power but I can't find many other dynos back to back to compare single 3" to dual 3" or single 3" vs 4" so take it as you will
https://www.performancetrucks.net/fo...totype-538474/
I'm not saying anything is gonna happen if you don't tune it after you upgrade the exhaust. But I would want the tune optimized with the freer flowing exhaust. And the tune may need a small adjustment with the higher flowing setup to be spot on.
My current truck picked up very considerable power after the tune when I put headers on it. My F body car picked up considerable power when I did headers and exhaust and the tune didn't make much of a difference. Not sure what the deal was there but my truck didn't seem to be any faster after the headers and exhaust, but after it was re tuned with the headers and exhaust it was a huge difference. The truck was already tuned before the headers. So going forward I'm going to always want a tune touch up after even a small exhaust change. Which makes since anyway since it flows more even if it's just a little.
Last edited by 00pooterSS; Dec 3, 2019 at 12:53 PM.
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Launching!
Joined: Mar 2012
Posts: 216
Likes: 25
From: Enid, Oklahoma
Yea just Speed Engineering headers their ORY and SLP catback, all 3”
It runs soo much better over the mail order tune but that was to be expected
It runs soo much better over the mail order tune but that was to be expected
TECH Enthusiast
Joined: Feb 2018
Posts: 642
Likes: 300
From: Michigan
Congrats! I bet it's a monster now. I curious how much power you'd pick up with a nice merge and a 3.5" or 4" cutout.
How is driveability? Your cam is essentially a tweaked version of a BTR stage 3 right? I bet it pulls hard up top.
How is driveability? Your cam is essentially a tweaked version of a BTR stage 3 right? I bet it pulls hard up top.
Last edited by Bob570; Dec 4, 2019 at 07:57 PM.
Hmmmm. Honestly it made what I thought it would make.
But a dyno reads torque, not horsepower. So when torque was acting up...well that's not how this works.....
Horsepower is a formula that someone came up with based off of torque and rpm.
I'm not bashing you at all, please don't take it that way. As long as your tuner is good I'm sure the car rips regardless of what the dyno says.
But a dyno reads torque, not horsepower. So when torque was acting up...well that's not how this works.....
Horsepower is a formula that someone came up with based off of torque and rpm.
I'm not bashing you at all, please don't take it that way. As long as your tuner is good I'm sure the car rips regardless of what the dyno says.
Thread Starter
Launching!
Joined: Mar 2012
Posts: 216
Likes: 25
From: Enid, Oklahoma
Hmmmm. Honestly it made what I thought it would make.
But a dyno reads torque, not horsepower. So when torque was acting up...well that's not how this works.....
Horsepower is a formula that someone came up with based off of torque and rpm.
I'm not bashing you at all, please don't take it that way. As long as your tuner is good I'm sure the car rips regardless of what the dyno says.
But a dyno reads torque, not horsepower. So when torque was acting up...well that's not how this works.....
Horsepower is a formula that someone came up with based off of torque and rpm.
I'm not bashing you at all, please don't take it that way. As long as your tuner is good I'm sure the car rips regardless of what the dyno says.
Thread Starter
Launching!
Joined: Mar 2012
Posts: 216
Likes: 25
From: Enid, Oklahoma
Yea i really wish i could have had my merge and cutout on there before the dyno, i may go back after i have it installed to see what it picks up. And yea its somewhere in the BTR 3/4 realm. Driveability is well....it drives like a big cam, i cant say its really good because it does buck at low rpms and gets annoying sometimes but i kind of expected it to. I bought a turbo kit from Huron so the cam wont stay in there for long anyhow.
Yea i really wish i could have had my merge and cutout on there before the dyno, i may go back after i have it installed to see what it picks up. And yea its somewhere in the BTR 3/4 realm. Driveability is well....it drives like a big cam, i cant say its really good because it does buck at low rpms and gets annoying sometimes but i kind of expected it to. I bought a turbo kit from Huron so the cam wont stay in there for long anyhow.
Thread Starter
Launching!
Joined: Mar 2012
Posts: 216
Likes: 25
From: Enid, Oklahoma
yes sir! you and me both lol ....wont be til this summer or later would be my guess. The Huron turbo group buy doesnt end til february so wont even get the kit til then. I'll def make a post when its done tho!