Dynamometer Results & Comparisons Dyno Records | Dyno Discussion | Dyno Wars

408 little low on power

Thread Tools
 
Search this Thread
 
Old Mar 28, 2011 | 01:08 PM
  #21  
69ls6's Avatar
Thread Starter
Teching In
iTrader: (5)
 
Joined: Dec 2010
Posts: 48
Likes: 0
From: prestonsburg,ky
Default

[quote=jimbob;14702321]For E85, the numbers thrown around is generaly 3% more power. From what I'v seen at 12-12.5 compression look for about 15 more, maybe 20 rwhp (if your lucky) from the ethanol use. If you bumped comp up to 13-14 to 1 comp you can get more out of the engine. Really, E85 is not going to make much difference for timing requirments with our good heads, you'll probably still find low 20's work for max power and 2 or 3 degrees more timing added works for max torque. I'm finally swithching, we have a pump with 25 freeway miles now. If racing with it buy a cheap ethanal weigh set, just to make sure you have the same amount everytime you go to the track. On our more powerful 383 18* engine we're at 14.4 to 1. We will mix 109 with 90% ethanol. We will be ordering E100 and mixing our own. We could go 100 straight but you can never guarantee it's going to fire when it gets cold. Your in that compression range that E85 starts to really shine. There is some real good E85 info over at Corvette forums C6 section...

probly won't go that far..this is a street/strip car,figured 12.5-1 was to the edge of running race fuel..with 12.5-1 do you think afr 225 heads will flow enough or needs to be cut and opened up with what cam I have.
Reply
Old Mar 28, 2011 | 04:40 PM
  #22  
jimbob's Avatar
11 Second Club
iTrader: (4)
 
Joined: Nov 2001
Posts: 787
Likes: 0
From: Woodinville, WA
Default

[QUOTE=69ls6;14702418]
Originally Posted by jimbob
For E85, the numbers thrown around is generaly 3% more power. From what I'v seen at 12-12.5 compression look for about 15 more, maybe 20 rwhp (if your lucky) from the ethanol use. If you bumped comp up to 13-14 to 1 comp you can get more out of the engine. Really, E85 is not going to make much difference for timing requirments with our good heads, you'll probably still find low 20's work for max power and 2 or 3 degrees more timing added works for max torque. I'm finally swithching, we have a pump with 25 freeway miles now. If racing with it buy a cheap ethanal weigh set, just to make sure you have the same amount everytime you go to the track. On our more powerful 383 18* engine we're at 14.4 to 1. We will mix 109 with 90% ethanol. We will be ordering E100 and mixing our own. We could go 100 straight but you can never guarantee it's going to fire when it gets cold. Your in that compression range that E85 starts to really shine. There is some real good E85 info over at Corvette forums C6 section...

probly won't go that far..this is a street/strip car,figured 12.5-1 was to the edge of running race fuel..with 12.5-1 do you think afr 225 heads will flow enough or needs to be cut and opened up with what cam I have.
Yep, 12.5 is on the ragged edge for 92 octane depending on your actual DCR, cooling, engine VE, DA ect. I actually have 12.5 to 1 on my 401 Cubed LT1 "old school" But it has reverse cooling and seems to work ok. Timing down low blows though! Most Ls1 up here do OK at 12.0 comp with E10 92 octane. We also don't get past 90* in the summer so, this works out. If I was in the heat and had really good flowing heads, I might look for 12 to 1 SCR and 8.7 DCR (max), if using pump fuel. You can still get good power at 12.0 comp on E85.

You could also add Meth injection if your car doesn't like summer months (on premium pump gas).....E85 would fix any problem with octane at your compression...

AFR 225's work really well on 40X engines. I like there bigger heads on 42X-45X. The extra flow of the bigger heads and cubes really should require a great SP manifold to get every last ounce of power. I know my heads will be choked with a FAST and that's why I ordered my porting with smaller intake CC. Yeah, I give up 15-20 cfm @ .7 lift. But I'm not going that high lift anyway + Ported LS7 FAST only flows like 310 CFM MAX. You'll be fine with the 225's. With E85 on board you should easily go over 550. That's just a number anyway, but as long as you dyno at the same place you'll get a good handle on how much you gain. That cam you have will like the extra comp and should really show big gains in the TQ area.

One more thing. Advance your cam to 4 degrees total with that cam (108 ICl). That late abdc of that cam does not go well with stock or Fast intake. It may not show up as a double tq bump at the dyno but it will drop your low to mid range tq. That cam on a 408 has more than enough ability to go well past 7200rpm (most hyd lifters and springs don't like it much past this rpm anyway) so why not put your useable range down to below 7200....A ported FAST will generally peak at 6400-6500 on a 408 cube engine.

Last edited by jimbob; Mar 28, 2011 at 05:05 PM.
Reply
Old Mar 28, 2011 | 04:46 PM
  #23  
Johnnystock's Avatar
TECH Addict
15 Year Member
Photogenic
Photoriffic
Liked
iTrader: (6)
 
Joined: Feb 2007
Posts: 2,685
Likes: 41
From: Canada
Default

Originally Posted by MikeG
You already said it man. The LS2 intake is horrible, your exhaust setup is horrible. Get the new headers/exhaust on and get rid of that intake for a FAST and you should break 500 no sweat.
this^^
Reply
Old Mar 28, 2011 | 05:36 PM
  #24  
69ls6's Avatar
Thread Starter
Teching In
iTrader: (5)
 
Joined: Dec 2010
Posts: 48
Likes: 0
From: prestonsburg,ky
Default

[quote=jimbob;14703346]
Originally Posted by 69ls6
Yep, 12.5 is on the ragged edge for 92 octane depending on your actual DCR, cooling, engine VE, DA ect. I actually have 12.5 to 1 on my 401 Cubed LT1 "old school" But it has reverse cooling and seems to work ok. Timing down low blows though! Most Ls1 up here do OK at 12.0 comp with E10 92 octane. We also don't get past 90* in the summer so, this works out. If I was in the heat and had really good flowing heads, I might look for 12 to 1 SCR and 8.7 DCR (max), if using pump fuel. You can still get good power at 12.0 comp on E85.

You could also add Meth injection if your car doesn't like summer months (on premium pump gas).....E85 would fix any problem with octane at your compression...

AFR 225's work really well on 40X engines. I like there bigger heads on 42X-45X. The extra flow of the bigger heads and cubes really should require a great SP manifold to get every last ounce of power. I know my heads will be choked with a FAST and that's why I ordered my porting with smaller intake CC. Yeah, I give up 15-20 cfm @ .7 lift. But I'm not going that high lift anyway + Ported LS7 FAST only flows like 310 CFM MAX. You'll be fine with the 225's. With E85 on board you should easily go over 550. That's just a number anyway, but as long as you dyno at the same place you'll get a good handle on how much you gain. That cam you have will like the extra comp and should really show big gains in the TQ area.

One more thing. Advance your cam to 4 degrees total with that cam (108 ICl). That late abdc of that cam does not go well with stock or Fast intake. It may not show up as a double tq bump at the dyno but it will drop your low to mid range tq. That cam on a 408 has more than enough ability to go well past 7200rpm (most hyd lifters and springs don't like it much past this rpm anyway) so why not put your useable range down to below 7200....A ported FAST will generally peak at 6400-6500 on a 408 cube engine.
I thought there was a station that sold e85 locally,but theres not,so no e85.Is there anything to do beside just putting in e85 in tank..I've heard that it made more power and cooler.
Reply
Old Mar 28, 2011 | 05:56 PM
  #25  
jimbob's Avatar
11 Second Club
iTrader: (4)
 
Joined: Nov 2001
Posts: 787
Likes: 0
From: Woodinville, WA
Default

[QUOTE=69ls6;14703629]
Originally Posted by jimbob

I thought there was a station that sold e85 locally,but theres not,so no e85.Is there anything to do beside just putting in e85 in tank..I've heard that it made more power and cooler.
The biggest thing is to have enough pump and injectors. The "General" rule of thumb is about 30% more fuel needed. There is some metals that don't like ethanol, but you should be ok. Look at the thread going on in the fueling and injection section....I know brass doesn't like it but I have never actually seen any issues with it. Stainless is all good....
Reply




All times are GMT -5. The time now is 05:44 AM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE