gjestico

iTrader: (5)

I have been driving this for a couple of weeks now and it has been running great. Its been a long time since i had a 'hotrod' and its fun to be on the street again. I would like to tune it up to its full potential. Looking for suggestions.
As now :
'02 LQ4 6.0
Untouched 243 heads swapped
Edbrk Performer rpm dual plane
Holley 670 street avenger (box stock jetting)
MSD 6010 with #2 curve pill
700r4 trans with 2300 stall, 3.36 rear gear.
1 3/4 headers to dual 2 1/2 pipes.

gjestico

iTrader: (5)

I think I should start with the carb. I guess I will be needing to get a selection of jets.
Forgot to mention, engine has a Comp 269HR cam 216/220 .525/.532 114d

bigchief52780

iTrader: (10)

how does it feel with that cam and head setup?

79-mailbu

how hot does the fuel regulator get?

3pedals

iTrader: (3)

time to get a wideband 02 setup, and start tinkering. are you runing a map sensor to get some vacuum advance? there is power and throttle response hiding in the timing and jetting for sure. Personnally I like to run lots of initial timing, it really improves throttle response.

ZONES89RS

iTrader: (25)

Two things to do off the top would be a 750 carb and custom tuned timing curve, will feel like a different car.

gjestico

iTrader: (5)

It runs great right now. Throttle response is good and it really wants to go off idle.
I am running map sensor. #2 pill curve results in about 14 degrees initial at 750 rpm. 8 Map advance at idle puts timing at about 22 degrees idling, according to MSD guage screen.

Question : In the MSD pro-data link, is the timing curve displayed on the scrren the current curve off the pill ?

It really wants to rev. I have bumped the rev limit from 5500 to 6100, and now 6500.
If I could get my trans auto shifting to cooperate I wouldnt have to touch the shifter.

Zone, You think there is much to be had going to a 750 carb from a 670 ? I chose the carb on the 'smaller' side as i wanted it to run great off idle and in traffic. It does.

85LSburb

iTrader: (1)

I had the same set up in my burb with 69 front jets and 33 nozzel. It had perfict throttle response. I could punch it from idle and spin my tire with no bog or anything weird. Then i put a 1000 cfm throttle body injection on it and it is like a compleatly diff motor. It has way more power. The efi puts out about as much as a 750 holley in the power department. My 670 was to small and causing funny things with my A/F ratio that were hard to fix. I still have the #2 pill in it tho.

ZONES89RS

iTrader: (25)

I have a 750 and it is perfect off idle and does well in traffic, it is just one thing to do to get the most from the top end.

team39763

iTrader: (3)

I thought I read somewhere that the 670 avenger is wet-flowed and the 750 is most likely dry flowed which would make them flow similar in stock form(not HP or ProForm body).

Pop N Wood

iTrader: (1)

Carbs are rated by airflow, not displacement. That 6 liter is making a lot more HP then a traditional first gen SBC which means it is moving more air. Most guys go at least 750 cfm with their stock LS1's and bigger. Your cam is pretty conservative, but it is still bigger than an LS6 cam. A 750 would have been a better choice for that motor.

FWIW I have a stock LS2 (i.e. 243 heads and LS6 cam) with a single plane intake and Holley 750 DP. Took me a while to figure out the combination but now I have no bog with excellent throttle response. I can drive all day and never go over 2000 RPM. The combo of a classic double pumper and single plane intake makes tuning an LS more of a chore, but not because the carb is too big. It just needed something other than out of the box tuning.

If I were you I would enjoy the current carb. Like suggested, get a wideband and start tuning. A different timing curve will make a difference in power. Later on you might try a bigger carb. you won't lose anything down low and there is unquestionable some power to be picked up on the top end.

BTW, moving that fuel regulator off the head wouldn't be a bad thing either.

gjestico

iTrader: (5)

Thanks for the replies. I appreciate the tech help here.
Last night I modded the spark curve to be 18d 0 to 1000 rpm, then ramp up to 36d at 3300 rpm. Map advance is 6d on top of that at idle. It felt about the same as the #2 pill. Hard to tell by seat of the pants.

I was thinking about cutting the plenum divider in the manifold. If my carb is on the small side then its even worse that each bank is seperated ?. I guess I could also try an open spacer which would achieve more plenum and reduce the seperation.
Surpisingly, I dont have a ton of hood clearance with this engine. My air cleaner is a drop base style , like a shrink fit on the carb. I think i could squeeze a 1 inch spacer in there.

gjestico

iTrader: (5)

So I have been doing a little tinkering and finally made it to a real drag strip.
I now have a 770 Vac secondary Ultra street carb.
Best time at dragstrip was 12.68@109 ; 2.0 60 ft. Track is 50 feet above sea level. Temp was about 65 degrees. Regular street tires.
Yes I know the 60ft would be lots better with drag radials , but I prefer to run on my street tires just as the car would be on the road. I am mainly looking to see what kind of mph I get as that indicates power - I believe ?
Car weighs 3590 on the drag scale with my fat butt on board.
I had expected a bit better MPH than this. I have read of many LS1 98-02 camaros on LS1tech that get times like this with with just an exhaust and air intake mod ?. Perhaps its time to book a dyno day and bring some tunage.

ZONES89RS

iTrader: (25)

The faster you can 60 foot the fasterthe car will start to get to making mph, so you are not doing too bad for that weight, but will not know till you get a good short time to complete a good pass.

speedtigger

iTrader: (16)

A 3000 to 3600 stall, 750 HP carb, 3.73 or 4.10 gear and some tuning and you would probably be in the 11s. It is all the little things in the combo that all add up.