Forced Induction Superchargers | Turbochargers | Intercoolers

Breaking up in boost

Thread Tools
 
Search this Thread
 
Old Aug 5, 2018 | 02:11 PM
  #1  
jimmyg's Avatar
Thread Starter
TECH Fanatic
10 Year Member
 
Joined: Jun 2014
Posts: 1,533
Likes: 12
Default Breaking up in boost

car runs fine but breaks up as soon as the boost kicks in. Fuel pressure drops 2lbs@WOT.Checked the fuel filter , looks fine. Plugs? I guess what Im Asking is what are the main causes? Ly6/whipple2.9 running 93/water/meth. Plugs are TR7ix gapped @.42
Reply
Old Aug 5, 2018 | 03:51 PM
  #2  
ls3fox's Avatar
7 Second Club
10 Year Member
Photogenic
Photoriffic
Liked
 
Joined: Apr 2015
Posts: 692
Likes: 149
Default

gap the plugs tighter and figure out why fuel pressure drops it should increase with boost not drop
Reply
Old Aug 5, 2018 | 04:14 PM
  #3  
jimmyg's Avatar
Thread Starter
TECH Fanatic
10 Year Member
 
Joined: Jun 2014
Posts: 1,533
Likes: 12
Default

I ordered plugs . I’ll try swapping them out . If it don’t work, I will swap out fuel pump(Walbro 450) . The FPR is not boost referenced. Mast motor sports tuned it. They set the fuel pressure @65lbs . I think they control fuel with injector timing? What ever they do, it’s been working fine for 10-12k. Plugs and fuel pump been in about the same. Pretty sure it’s a modified ls9 tune.
Reply
Old Aug 6, 2018 | 07:24 PM
  #4  
stevieturbo's Avatar
9 Second Club
 
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
Default

Is this a new problem or has it ever ran correctly ?

How much water/meth ?

42thou is on the large side for a boosted build unless it has extremely powerful coils.
Reply
Old Aug 6, 2018 | 08:13 PM
  #5  
jimmyg's Avatar
Thread Starter
TECH Fanatic
10 Year Member
 
Joined: Jun 2014
Posts: 1,533
Likes: 12
Default

It’s been together running my fine since 2015. Im hoping I accidentally put 100% water in meth tank? Seems to be not getting fuel up top but pressure seems ok . If plugs were bad wouldn’t it run like **** all the time? I ordered new TR7ix what should I gap them at? I’m only running 13-14 lbs. 50/50 water meth progressive snow kit I think it’s the biggest nozzle they have , a 6?
I’ll look it up
Edit. it’s a number 6. 625 ml/min


Reply
Old Aug 6, 2018 | 08:30 PM
  #6  
stevieturbo's Avatar
9 Second Club
 
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
Default

Certainly too much water and the engine will be less happy although it's a relatively small nozzle.

Any plug/performance issues are more likely to show under load than with no load....same as anything really.

Always be careful gapping precious metal tipped plugs, never touch the tips themselves, so gap carefully. I prefer the round wire type gauges over regular flat feeler blades.

I'd doubt you'd need to go as low as say 25thou, but it would do no harm either. Anywhere 25-30thou should be fine.
Reply
Old Aug 7, 2018 | 08:43 AM
  #7  
dr_whigham's Avatar
The Scammer Hammer
Veteran: Marine Corps
15 Year Member
Photogenic
Liked
iTrader: (49)
 
Joined: Apr 2009
Posts: 6,717
Likes: 24
From: Lafayette, LA
Default

I'd gap between .028 and .032... How much boost are you seeing?
Reply
Old Aug 7, 2018 | 04:06 PM
  #8  
jimmyg's Avatar
Thread Starter
TECH Fanatic
10 Year Member
 
Joined: Jun 2014
Posts: 1,533
Likes: 12
Default

13-14 lbs
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Aug 7, 2018 | 04:22 PM
  #9  
3 window's Avatar
TECH Addict
10 Year Member
Liked
Loved
Community Favorite
iTrader: (1)
 
Joined: Aug 2014
Posts: 2,051
Likes: 187
Default

.020-.022 gap
Reply
Old Aug 10, 2018 | 01:04 PM
  #10  
dr_whigham's Avatar
The Scammer Hammer
Veteran: Marine Corps
15 Year Member
Photogenic
Liked
iTrader: (49)
 
Joined: Apr 2009
Posts: 6,717
Likes: 24
From: Lafayette, LA
Default

Originally Posted by jimmyg
13-14 lbs
PD blower.... 13-14... I'd try .028 and see how she reacts.
Reply
Old Aug 10, 2018 | 07:36 PM
  #11  
jimmyg's Avatar
Thread Starter
TECH Fanatic
10 Year Member
 
Joined: Jun 2014
Posts: 1,533
Likes: 12
Default

It was fine on the stock gap .42? For a year or so. I think the plugs are junk. They finally showed up in the mail, so I’ll put them in in the morn @.28 and see what’s up.
Reply




All times are GMT -5. The time now is 09:21 PM.

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