npbassman

93 LT1 with a ZF.

59k on the clock and the only mods are shorty headers and corsa cat back. The car runs very well. It's got plenty of power, a nice idle, and it starts up every time (knock on wood). I'd take it on a 300 mile round trip without a worry. The only thing that may be wrong is I sometimes think I hear a slight ping in 5th or 6th under load but I've had 3 car guy friends take it for a ride and they said wouldn't worry about it.

That said, with no aftermarket heads or cam would I still benefit from a tune? The cost benefit for me would be a little more power, maybe better mileage, and perhaps removing that mystery ping (if it even exists). I'd send them a data log beforehand.

What do we think?

weaselbeak

I don't know how touchy the LT1 is since I have a l98 but I think your system should be fairly tolerant of exhaust changes with the stock tune. I bet your fine as it is.

GREGGPENN

Try gas from a different gas station and clean your engine by running seafoam thru it.

What grade of fuel are you running?

PLRX

Are buying Costco gas?

illenema

Add a bottle quality octane booster.
A tune might make it worse.

cv67

Leave it alone

JrRifleCoach

On the contrary. My PCMforless tune on an otherwise stock 86 A4.
My best - 13.89 @ 99.x mph

jaa1992

All stock LT1 with just exhaust changes - its your money but I didn't do it and the car ran fine. Stock L98 with open air cleaner and better exhaust - yea it may be worth the cost.

Now when you start making real changes - get a tune. Make sure you include the price in the mod-budget.

npbassman

Thanks for the replies. I'm running 93 octane from name brand providers (Sunoco, Mobile, etc) but I'll try to go to a different station next fill up to see if the "ping" goes away. Keep in mind that three friends (who have all owned BB & SB hot rods at one point or another) have told me to not worry about it so this just may be me being paranoid. I'm not too worried about it but I though a tune may improve the overall performance of a stock vehicle and possibly the "ping" just in case I'm not crazy. I'm leaning on the side of just leaving it alone. If I decide to put long tubes and a cam in there I'll revisit the tune.

Regarding Seafoam, the interesting thing is I did seafoam the engine about a month ago and to my surprise, I got some smoke while I gently poured SF into the brake booster hose but didn't get the huge smoke show after letting it sit for an hour. My opinion of SF is that it helped me find a small exhaust leak while I was pouring it in but it didn't do much else as far as increasing driveability or overall performance. The car drives the same as it did before SF.

tmorand

FWIW. I just finished a 383 build on my 91. Everything was different than stock. So I did what I thought was right and ordered a tune from PCM for less for the initial startup and run-in. It ran HORRIBLY. I had to take it to the "local" late model GM tuner to have him re-tune and dyno. This guy told me that the mail order tune was way off and a waste of money. He told me it would have run better on the STOCK tune until I got it to the dyno.

Bottom line is- mail order tunes are a GUESS. the best money is spent on the dyno.

JrRifleCoach

npbassman, if your pinging on top tier premium, there is something else that needs attending to. Going with a custom tune also means that you'll need to record the data stream from the ECM for analysis. Alvin worked with me to make a few sensor adjustments/replacements then proceeded to work on the performance side. I sent him a dozen recordings in all and he had the engine running smoother and there was a noticeable improvement (SOTP) to power as my track numbers confirm. Later when I changed up the cam and few other tweeks, the tuning process took fewer runs and the results were amazing. So getting the tune earlier enabled me to have a good baseline. Remember the tune from Alvin is a custom for your engine only. Not some cheesy bump to a few perimeters that work with all the other engines in the world.

Anyways don't let the naysayers here persuade you. They haven't the experience to make the call as some of us do.

Kirk Emsley

What did it run before the tune?

93 ragtop

This may open a can of worms, but IMO and every tuner I have worked with.... In addition to a tune, change the T-stat from the factory 180 (LT1) to a 160. It does make a difference.

aklim

How did you ascertain the difference the thermostat makes?

dizwiz24

COmbination of 160 tstat and reprogrammed fAns on my 93 dropped coolant temp from 215 to 174f

i believe this will make optisparks last longer - reducing the heat they are subjected to

aklim

Believe being the key word

93 ragtop

Quote:

Originally Posted by aklim

How did you ascertain the difference the thermostat makes?

Dragstrip. Difference in launching with the motor cooled down to 160 or so verses the 190-200 makes 1 tenth and 1 mph difference in the 1/8.

GREGGPENN

Get used to looking at the dates of threads/posts. You asked about a post made in 2012! JrRifleCoach doesn't appear to have logged onto this forum for a couple of years either. (You can find date of last post under statistics tab of profile.)

So....You won't get your answer....making this necromancing pointless. OTOH...it would be fun if he popped out of nowhere!

JrRifleCoach

Surprise. Well Gregg your statement about a "couple of years" is a bit exaggerated. Months maybe, not years.
Since I sold the 86, I just get bored listening to the same experts/buffoons beat their chests. I'd name a few but whats the point?
I have liked your style and shared experiences.

Whatever......

JrRifleCoach

Didn't get to the track before the change. Nor after the cam change.
Life got in the way as it does. I researched archives of Car & Driver to find my numbers were better by a few tenths and MPHs.
I appreciated the overall performance from stock. It wasn't the fastest 86 on the block, but it was the best sounding and most reliable.

Any questions feel free to PM me.










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