NEW FROM MIDWEST

Hi
New member from the midwest. Tuning 1995 lt1 for road racing and am interested in maybe getting some tips from some of the members.

Thanks
Wileyone

:welcome:

Here is a link for AWESOME LT1 information: http://fbodytech.com/eehack-2/

dave w

welcome.. quite a few lt1s here these days

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Originally Posted by steveo

welcome.. quite a few lt1s here these days

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Thanks Stevo…….looking now

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Originally Posted by steveo

welcome.. quite a few lt1s here these days

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I came from a world of methanol and one wire to a magneto so this is somewhat overwhelming. I built this lt1 to run in a road racing series which is dominated by many LS engines. Maybe I should have my head examined for going against the grain and building an LT but it is too late now. (I also like the challenge) SCCA rules dictate that the cam can be the Chevrolet Hot cam with 1.6 rockers. I might be a little high on the compression and around 11:1 instead of their 10.6 I have 30# Ford injectors. I am allowed to do some porting on the heads and intake. (One inch deep into the ports and also open up the ports to match the gasket) I built a complete forged lower end so I can beat this thing to death. I still have the Airflow sensor and Oxy sensors but may try without.
First couple times out the thing pulled very well in 2nd and 3rd gear with a 3:90 gear. In 4th and 5th I could feel the timing retard under load which made it a real turd for the long straights.

I am going back out in a couple of weeks and have the below changes using TunerCat.

EGR DELETE: In ECM constants I entered "0" in EGR enable Max RPM from preset 6375
CLOSED SPARK TPS Spark Advance vs rpm: Changed bottom three to 34 deg
EXTENDED SPARK ADVANCE: Changed all values to 34 deg
In the two MAXIMUM SPARK RETARD VS RPM's I set all values to "0"
Originally I was using 93 octane only gas and now have gone to racing gas. Maybe this would cure the timing retard but I didn't want to deal with it. I wanted my timing to remain at 34 deg throughout the range.
I would like to fuel the thing with a constant air fuel mix and am looking at that now.

I hope you don't laugh at what I have done so far......remember I am old school trying to learn something new.

I'm thinking your still using the Original LT1 computer?

One advantage of the 94 - 95 LT1 computer is "Flash" programming, most all other OBD1 computers use chips. The EE Trimalyzer is a very helpful " Tuning Tool". Most all other OBD1 "Tuning Tools" require skills with Microsoft Excel, but the EE Trimalyzer Does Not require Excel skills.

Using a Wide Band O2 (WBO2) tuning tool with EE Trimalyzer is a proven path to "Optimal Performance".

dave w

you can use eehack and its timing skew feature to determine optimal timing (it can just add or subtract a few degrees for you) in real-time on a few track runs without constant re-flashing

i agree with disabling the knock sensor and just log for knock instead, especially with a stout engine and race gas you're less likely to break things, false knock can definitely ruin your run.

for fuel, once you have a good base fueling table (maf or ve or whatever) you can just disable power enrichment and closed loop and set a good target AFR in the open loop afr target table. you can go a bit leaner at high vacuum to avoid loading up on decel and idle.

then use EEHack to override your AFR target in realtime at the track to see what works best for power output and tweak from there