RaleighSS

So i have a LS6 short block with ported LS6 heads and Mild cam. (about to be rebuilt) Since most tuners tune for max HP and a huge part of the client base want max HP, us road racers are not so concerned with max HP what numbers should I be most concerned with on a dyno tune for road racing?

What questions should I ask as far as the tune itself ? What A/F Ratio is best ? Just looking for the general knowledge so I can be informed when the tuner is doing his magic :-)

rustyguns

you want a real flat torque curve. Tuner will understand

how does the old saying go? Horsepower sells cars and torque wins races?

Bill Dearborn

I would think you would want the air fuel ratio to be a little on the rich side Vs leaned out. More like stock.

Bill

davidfarmer

A good tuner will look for maximum power across the range, not just a peak. The software makes it much easier than it used to be. We have a great tuner down our way (he's in Mooresville) if you want to make a short road trip. I agree with above, a little rich, a little less time.....you will run cooler/safer, and only give up a tiny bit of power if any.

sothpaw2

This is good advice. I took my car to ECS. They do some road racing of these cars themselves. I walked in and said I don't want any extra power, I just want a nice safe tune with special emphasis on #7&8 cyl since these seem to be the problem cylinders that go. I kept emphasizing <I don't want the power just reliability> Hopefully that worked. I don't really understand enough of the details to credibly review the tune.

What happened with your engine--I thought you had an exhaust issue? Did you ever have the oil analyzed? I find that's worth it and should catch something if it's a progressive failure.

Jorge

A good tuner that understands the right AFR for the fuel you use ethanol or none ethanol (E00 E10 E65 E85) and set up timing for torque with no knock.

RaleighSS

Well we thought it was the exhaust as it was loosing power on top end dropped the exhaust at the headers ... no change still 15 or so down on power ... leak down test shows 7 very bad and 2 questionable sounds like it is coming from the rings not valves .... so think the bottom end is the problem ... Waiting for the builder to come by and let me know what he thinks but kinda hard to screw this test up

RX-Ben

There is no one AFR to shoot for. At max torque you want a fatter AFR, can lean up after that to max hp. You should be south of 13 on all, probably varying from 12.5-12.9.
Did they screw in the wide band in the headers or out the tail pipe? In the pipe can give less accurate readings.

You can't individually tune each cylinder with an LS1 PCM. To have any idea of what is going on in #7, you'll need an EGT there.

I'd re-ring before you do anything else, it isn't going to cure itself.

rustyguns

did you run thin racing oil? i always feel that wastes main bearings

or redlining the engine when oil temps are under 160 ....... i see guys doing this a lot !

DOUG @ ECS

We are well "trained" in road course tuning, and I absolutely tune differently for a track car compared to a drag or street car. I have literally 100's of hours of road course tuning data, and feel confident that our tune will not be the cause of engine failure.

Thanks for the business!

sothpaw2

Me too! That's why I mentioned it--the OP should go to you or if he can not make the trip, someone down south with similar experience. I think he would be well served to emphasize conservatism to his tuner as that might be what messed his H/C engine up this time.

AU N EGL

is this why one should tune for #7

or but the best two flowing injectors on #7 and #8
and slightly hotter spark plug on 7 and 8

RX-Ben

Well, you want to protect the weakest link.
But you need to know what is going on - so you need an EGT on 7/8 and at least one reference to another cylinder.

SouthernSon

You have an excellent start; mild cam (not as bad on springs), ported for flow and sticking with the LS6. Now, simply tune to the rich side, 12.4 or 12.5. I blew up a perfectly good LS6 last year with lean tune (melted #7).
410 to 415 RWHP is plenty for all kinds of fun and long life. Get a good oil such as redline or amsoil since mobil 1 is an entirely different animal nowdays. good luck.

Wasserott

I spent some quality time with Doug and his crew from ECS last week and I will say i was very impressed. That man has a good head on his shoulders and I take him for his word. Something about not his first rodeo...and yes, not mine either when it comes to seeing vendor talent.



More to come when things get warmer!

Wicked Weasel

Its nice to have a few cars that are on the track around 15 days a year to collect and review data from. My car has been taken apart a few times and to date there has been no signs of a poor tune.

waddisme

So you are rebuilding instead of doing the crate motor?

I have 16 track days on my motor tuned by Nick Williams. Other people with similar motors make more HP, but Nick knows what I do with car, so it is tuned accordingly and hopefully safely. That being said, I am living proof that hp/tq don't mean squat on the track without driver mod. 500 rwhp and can't break 2:20 at VIR - sad sad sad.

DOUG @ ECS

Thanks for the kind words Chuck. Good luck on track this season!

travisnd

AU N EGL

Time and driver skill

C5Z stock LS6 with 380 some hp, some good aero and great driver is under 2:00.

Driver skill is more important then HP.

a great teacher will get you there wad