LT1 breakup at top end, dyno graph

Reply Subscribe

Thread Tools

Search this Thread

Aug 18, 2012 | 03:38 PM

StolenRedCamaro

Thread Starter

Staging Lane

iTrader: (2)

Joined: Jan 2008

Posts: 86

Likes: 0

From: Long Island

LT1 breakup at top end, dyno graph

So i figure i post this up and get some opinions

97 LT1, experiencing a breakup at the top end under load. New opti, NGK 3403 TR55 plugs, taylor 8mm wires done about 20,000 miles ago

Modifications are Cold air intake, Kooks 1 3/4 long tubes, catted Y pipe, GMMG catback, rear O2's delete, EGR delete

Im thinking ignition coil and or control module.. other thoughts?

Aug 18, 2012 | 03:46 PM

ale76051

On The Tree

iTrader: (2)

Joined: Jan 2008

Posts: 158

Likes: 0

From: DFW, TX

I had a similar issue with mine, but it would drop 150 hp instantly then come right back up then break up. I changed everything like you have and it ended up being the crank position sensor going out, thinking there was a lot of walk

Aug 18, 2012 | 04:40 PM

BIGCAT7274

TECH Enthusiast

Joined: Oct 2011

Posts: 556

Likes: 0

From: Apopka FL

there are a lot of things that could be causing it. i always start with the easy stuff first and put in a fresh set of plugs.

Aug 18, 2012 | 05:11 PM

guppymech

12 Second Club

iTrader: (7)

Joined: Jan 2010

Posts: 1,621

Likes: 3

From: Chicagoland

What's up with that graph, torque and hp are supposed to cross at 5252 rpm not 4500.

Aug 18, 2012 | 05:22 PM

forgedlt4

TECH Apprentice

Joined: Apr 2006

Posts: 326

Likes: 0

Quote:

Originally Posted by guppymech

What's up with that graph, torque and hp are supposed to cross at 5252 rpm not 4500.

HP and torque curves are probably graphed differently.

mine graph was the same way. hp and torque had their scales on each side of the chart

OP, as you can see, I am having a similar issue with mine, I still haven't figured it out either.

Aug 18, 2012 | 05:55 PM

96capricemgr

11 Second Club

iTrader: (1)

Joined: Sep 2004

Posts: 11,975

Likes: 15

with 20K on the Taylors I would be spraying them with a little water after dark to see if they arc.

Aug 19, 2012 | 02:09 PM

StolenRedCamaro

Thread Starter

Staging Lane

iTrader: (2)

Joined: Jan 2008

Posts: 86

Likes: 0

From: Long Island

I also had the car dyno'd when it was stock and it still had the same breakup at the top end, and after that is when I did opti/plugs/wires. I had the plugs out just recently (the ngks) when I did the headers and they were ok, I re gapped them too. wires I tucked in and zip tied away from the headers. I'll try that arc check idea though. and good call on the crank pos sensor, I'll try that after the coil. I'll probably just buy a new coil and module and re dyno and see if that works