PCM Diagnostics & Tuning HP Tuners | Holley | Diablo

Tuning for head swap / lower compression ?

Thread Tools
 
Search this Thread
 
Old May 18, 2005 | 03:32 PM
  #1  
Bad30th's Avatar
Thread Starter
12 Second Club
iTrader: (13)
 
Joined: Nov 2001
Posts: 1,898
Likes: 0
From: San Diego, CA
Default Tuning for head swap / lower compression ?

I went from 11.1:1 to 9.8:1 compression over the weekend with a head swap, I have a 222/224 114 cam and HPTuners.

Having a little trouble with hot starts now, stumbling to life and sometimes requiring a little pedal to keep it running until it smooths out. What tables do I need to adjust ?

I had previously reduced the low RPM idle VE somewhat to help with low RPM surging on the old heads setup (which worked great and helped considerably with cold starts).

I found with the swap to the new heads that the idle range was struggling and sputtering after the head swap (like it did when I went too far lowering the VE during testing), so I just now swapped the stock VE table back in, seemed a little better idle but still has the hot start issue.

Do I need to find a happy medium between stock and where I had it ? (I had it at 2000/90%, 1600/90%, 1200/85%, 800/85%, 400/85%).

Thanks for any help.

Rob (Bad30th)
Reply
Old May 18, 2005 | 08:39 PM
  #2  
jimmyblue's Avatar
Moderator
iTrader: (11)
 
Joined: Mar 2002
Posts: 12,604
Likes: 7
From: East Central Florida
Default

I would look at adding some spark advance, especially
at start and idle RPM. The low compression heads will
burn slower and could probably use some.
Reply




All times are GMT -5. The time now is 05:32 AM.

story-0
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-1
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-2
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-3
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-4
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-5
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-6
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
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE