C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

421 dyno run!

Thread Tools
 
Search this Thread
 
Old Sep 12, 2011 | 11:02 PM
  #1  
88BlackZ-51's Avatar
88BlackZ-51
Thread Starter
Race Director
Photogenic
Photoriffic
Liked
 
Joined: May 2003
Posts: 10,749
Likes: 41
Default 421 dyno run!

I finally had time to throw her on the dyno. The dyno was a DynoJet 224x.

I dyno operator mentioned that he recently had a Corvette dyno day where he mentioned that stock LS3's were throwing down 370-380 rwhp. After watching a few cars before mine it seemed that the dyno numbers were a tad on the low side, but either way it didnt matter because this was my baseline.

1st run- Coolant temp around 165

424rwhp@5900
458rwtq@4000


2nd run- Coolant temp around 210

434rwhp@5900
470rwtq@4000

It was very hard to tell exactly what the rwtq peaked at because the torque curve was so flat. There was also an issue with my car because my wires were too think, and the torque rating spiked in some areas, but I will add that at 2500 she made 450rwtq. Also the airfuel stopped working after the 2nd car which was a bummer, but I think I am somewhat close, but it would have been nice to see it.

The horsepower peaked at 5900, but stayed flat to 6300 rpm's then started a slight decline to 6500. I was kinda suprised that horsepower curve didnt drop more past 6000, but those heads still kept on trucking.

All in all I was pleased. I thought I would have made more rwhp, but I didnt think I would make that much rwtq. I do have to say that I am very impressed with that TPIS miniram intake as it makes power everywhere in the curve, and thats with 3.07's (4+3 still).

Many of you wanted to see what the little heads could do, and it is fair to say that these heads are maxed out. Everyone has there own opinion but I dont think this combo is maximized so there is a little left on the table.

The car was dynoed with the B&B reasonator, B&B mufflers, and 1 3/4 Hooker Headers. I do believe my exhaust is holding me back a tad (15-20rwhp). I will be making some changes and re-attending the dyno for some pulls.

All in all the car ran well, but I did notice that I had a header leak after the dyno runs. The car isnt quiet at WOT, and with the fan blowing on the car, it would have been very hard to hear that noise. I am kinda pissed off at myself for not checking the header bolts (bolt actually fell out, and other bolt was loose). Now I am not saying this affected my dyno number, but I do think its worth noting.

I am glad I got a baseline, and I am happy that Jim Barth built this motor. I wanted a motor to run on the street that was snappy and had excellent low, mid, and upper hp, and I got it!

Take care guys!







Last edited by 88BlackZ-51; Sep 12, 2011 at 11:45 PM.
Reply
Old Sep 12, 2011 | 11:26 PM
  #2  
Dr.Huxtable's Avatar
Dr.Huxtable
Burning Brakes
10 Year Member
 
Joined: Nov 2010
Posts: 1,006
Likes: 2
From: Spartanburg South Carolina
Default

Awesome bud! I'm happy your happy, good work and patience. It's been a long haul I know. Congrats

Oh and remember a number is nothin more just that, a number. The butt dyne is what counts. Jim told me your car was nothin short of badazz fast. Get that baby to the strip

Last edited by Dr.Huxtable; Sep 12, 2011 at 11:40 PM.
Reply
Old Sep 12, 2011 | 11:48 PM
  #3  
cv67's Avatar
cv67
Team Owner
15 Year Member
 
Joined: Oct 2004
Posts: 81,241
Likes: 3,062
From: altered state
St. Jude Donor '05
Default

Well ya made a few less hp and more rwtq than expected, cant complain about that. Strong street car regardless.
Reply
Old Sep 12, 2011 | 11:54 PM
  #4  
Caboboy's Avatar
Caboboy
Le Mans Master
20 Year Member
Veteran: Navy
St. Jude 20 Year Donor
All Eyes On Me
 
Joined: Mar 2002
Posts: 5,889
Likes: 2
From: Castro Valley Calif.
St. Jude Donor '03 thru '26
Default

Good job Rick, git'er tight now!

Hey..........I think I win the sweepstakes. Remember my guesstimates last month on IM?
Reply
Old Sep 13, 2011 | 12:10 AM
  #5  
Corvette0096's Avatar
Corvette0096
Race Director
20 Year Member
Liked
 
Joined: Aug 2000
Posts: 11,506
Likes: 4
From: Vancouver,Wa.
Default

Dyno jets all read high, Take it to the track and see what she does. Don't be like the supra guys.
Reply
Old Sep 13, 2011 | 12:11 AM
  #6  
weaselbeak's Avatar
weaselbeak
Racer
10 Year Member
 
Joined: Sep 2010
Posts: 327
Likes: 2
From: se iowa
Default

This is very cool! i think it's very rewarding when a plan comes to fruition.
Reply
Old Sep 13, 2011 | 12:20 AM
  #7  
1989TransAm's Avatar
1989TransAm
Racer
 
Joined: Oct 2007
Posts: 478
Likes: 1
Default

I think you will be able to get 450rwhp with your combination. A leaky header will effect the AFR. The O2 sensor will think the mixture is leaner than it is and add more fuel. So you need to go back when the AFR sensor is working. The torque is insane. So yes you have more left on the table.
Reply
Old Sep 13, 2011 | 07:56 AM
  #8  
bjankuski's Avatar
bjankuski
Safety Car
20 Year Member
Photogenic
Liked
Top Answer: 1
 
Joined: Sep 2001
Posts: 4,134
Likes: 531
From: Glenbeulah Wi
Default

Good numbers, hopefully this combination makes you happy for years.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

 Michael S. Palmer
story-1

2027 Corvette vs The World: Every Model vs Closest Competitor

 Joe Kucinski
story-2

10 Most Common Corvette Problems of the Last 20 Years!

 Joe Kucinski
story-3

5 MOST and 5 LEAST Popular Corvette Model Years in History!

 Joe Kucinski
story-4

2027 Corvette Buyer's Guide: Everything You Need to Know!

 Joe Kucinski
story-5

10 Things C8 Corvette Owners Hate (But Won't Tell You)

 Joe Kucinski
story-6

10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

 Brett Foote
story-7

Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

 Joe Kucinski
story-8

Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

 Michael S. Palmer
story-9

5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

 Joe Kucinski
Old Sep 13, 2011 | 08:16 AM
  #9  
87 rag's Avatar
87 rag
Drifting
 
Joined: May 2004
Posts: 1,747
Likes: 0
From: Port McNicoll Ontario
Default

Wish I could have been there Rick.
I will try to be there when you go back to re-test.

Amazing torque!!
Reply
Old Sep 13, 2011 | 09:01 AM
  #10  
yedister's Avatar
yedister
Pro
20 Year Member
 
Joined: Mar 2000
Posts: 658
Likes: 7
From: Perth Amboy New Jersey
Default

The motor is still new, it has not been broken in yet, the torque should get better after you put more miles on it. Which gear did you test it in?
Reply
Old Sep 13, 2011 | 09:06 AM
  #11  
esham's Avatar
esham
Pro
Supporting Member
15 Year Member
Liked
Loved
Community Favorite
 
Joined: Feb 2009
Posts: 541
Likes: 60
From: Auburndale Florida 1990 Vert, 6 speed
Default

Nice!
Reply
Old Sep 13, 2011 | 09:07 AM
  #12  
tpi 421 vette's Avatar
tpi 421 vette
Melting Slicks
20 Year Member
Active Streak: 30 Days
Photogenic
Top Answer: 1
 
Joined: Mar 2002
Posts: 3,105
Likes: 126
From: S.L.C. UT
Default

Congrats Rick. I hope you are happy with your engine
Reply
Old Sep 13, 2011 | 09:11 AM
  #13  
DDSLT5's Avatar
DDSLT5
Team Owner
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Jul 2002
Posts: 36,950
Likes: 68
From: This city NEVER sleeps! Frank's back yard!
Default

Originally Posted by bjankuski
Good numbers, hopefully this combination makes you happy for years.
I'll have to introduce you to Rick sometime.
Reply
Old Sep 13, 2011 | 09:20 AM
  #14  
96 lt-4's Avatar
96 lt-4
Drifting
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Oct 2005
Posts: 1,913
Likes: 48
From: Angier nc
Default

That is a LOT OF TORQUE everywhere.Gonna be hard to plant it but when she does I hope you are pointed in the direction you want to go!
Gonna be a blast to ride in.
Reply
Old Sep 13, 2011 | 09:49 AM
  #15  
5abivt's Avatar
5abivt
Safety Car
20 Year Member
Liked
Loved
Community Favorite
 
Joined: May 2002
Posts: 4,659
Likes: 82
From: Toronto ontario
Default

There's so many variables it isn't even possible to know how optimized the combo is. There's alot I want to say but it's just chatter since I'm no expert myself but I know I was spot on at guessingthe peak ! With a little tweaking of afr and timing and dropping those mufflers I think I would have been right on at guessing the #s too.

Sure the heads are undersized. I've believed it since i knew that the c6 zo6 uses a 427 with a 360+ cfm giant port. If anyone thinks they know more than GM engineers they need to face reality. The ls7 doesn't have a flat spot from 0-4000 rpm that's for sure. I don't actually think the heads are an issue here though. in my opinion With a bigger cam you would have had more torque across the range and held power longer if you wanted.

The dyno could be reading low and with tweaking you could end up with tons more power than you think you have. That's a ton of torque though wow !
Reply
Old Sep 13, 2011 | 10:14 AM
  #16  
383vett's Avatar
383vett
Race Director
20 Year Member
Liked
Loved
Community Favorite
 
Joined: Apr 2003
Posts: 17,695
Likes: 1,666
From: moraga ca
Default

Nice going Rick.
Reply
Old Sep 13, 2011 | 10:23 AM
  #17  
cv67's Avatar
cv67
Team Owner
15 Year Member
 
Joined: Oct 2004
Posts: 81,241
Likes: 3,062
From: altered state
St. Jude Donor '05
Default

Originally Posted by DDSLT5
I'll have to introduce you to Rick sometime.


Lets get some WOT road vids
Reply

Get notified of new replies

To 421 dyno run!

Old Sep 13, 2011 | 11:40 AM
  #18  
Kubs's Avatar
Kubs
Le Mans Master
15 Year Member
Community Builder
Community Favorite
Top Answer: 5
 
Joined: Oct 2007
Posts: 9,660
Likes: 3,359
From: Akron Ohio
2025 Corvette of the Year Finalist - Modified
2024 C5 of the Year Winner - Modified
2023 C5 of the Year Finalist - Modified
2022 C5 of the Year Finalist - Modified
St. Jude Donor '09-'10-'11
Default

Nice numbers! This thread needs video though....
Reply
Old Sep 13, 2011 | 01:00 PM
  #19  
88BlackZ-51's Avatar
88BlackZ-51
Thread Starter
Race Director
Photogenic
Photoriffic
Liked
 
Joined: May 2003
Posts: 10,749
Likes: 41
Default

Thanks guys....

Caboboy- Yes you were mightly close in your predictions. Say I sent you a pm in regards to those 2 bolts.

Yedister- 1:1 gear which is 4th (4+3).

96 lt-4- My 315/30/18 (RT-615's) certainly have there work cut out, but have been somewhat up to the task.

bjankuski- Thanks, and I am sure it will!

1989TransAm- I "hope" you are right. Jim also mentioned the same thing about the leaky header. I will get it back on the rollers.

5abivt- Mike I agree that there is a bit left in the combo.....I should have the eliminators on is a week or two. I fixed the exhaust leak, and I would like to strap it down again.
Reply
Old Sep 13, 2011 | 01:57 PM
  #20  
Yguy's Avatar
Yguy
Drifting
25 Year Member
Liked
 
Joined: Jan 2001
Posts: 1,408
Likes: 13
From: Dayton, Ohio
Default

congrats on the project Rick! It has definately been a long haul, but now that it's done, I hope you get a lot of fun from the car.
What's your driving impressions of just driving around? Off idle, thru traffic, how it runs just driving thru the gears, etc...
Reply



All times are GMT -4. The time now is 04:21 PM.

story-0
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2

Slideshow: Should you buy a 2020-2026 Corvette or wait for 2027?

By Michael S. Palmer | 2026-04-22 10:08:58


VIEW MORE
story-1
2027 Corvette vs The World: Every Model vs Closest Competitor

Slideshow: 2027 Corvette lineup vs the world.

By Joe Kucinski | 2026-04-20 17:58:41


VIEW MORE
story-2
10 Most Common Corvette Problems of the Last 20 Years!

Slideshow: 10 major Corvette problems from the last 20 years.

By Joe Kucinski | 2026-04-14 16:37:05


VIEW MORE
story-3
5 MOST and 5 LEAST Popular Corvette Model Years in History!

Slideshow: 5 most and least popular Corvette model years.

By Joe Kucinski | 2026-04-08 13:25:01


VIEW MORE
story-4
2027 Corvette Buyer's Guide: Everything You Need to Know!

Slideshow: 2027 Corvette buyer's guide

By Joe Kucinski | 2026-04-17 16:41:08


VIEW MORE
story-5
10 Things C8 Corvette Owners Hate (But Won't Tell You)

Slideshow: 10 things C8 Corvette owners hate, but won't tell you.

By Joe Kucinski | 2026-04-01 18:36:07


VIEW MORE
story-6
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!

Slideshow: Should you add one of these incredible Corvettes to your garage?

By Brett Foote | 2026-04-01 18:14:05


VIEW MORE
story-7
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)

Slideshow: Every Corvette Grand Sport explained

By Joe Kucinski | 2026-03-26 07:13:44


VIEW MORE
story-8
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!

Slideshow: Breaking down the 2027 Grand Sport, Grand Sport X, Stingray, and LS6 V8.

By Michael S. Palmer | 2026-03-26 13:48:45


VIEW MORE
story-9
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!

Slideshow: 5 reasons bad drivers crash sports cars & 5 ways to avoid a costly shame!

By Joe Kucinski | 2026-03-25 16:32:55


VIEW MORE