They should may that a sticky on here. Thats probably the best advice I have seen on here....now if people would just use it.

 

Let me guess you got that advice from this website somewhere? (not in the nitrous section there are actually people who read their plugs in this section and know what tuning a car really entails)

It seems every boosted car on this site aside from a handful over time and then over fuel the **** out of their motors to cover up the over timed condition.

They then think the tune is safe because it is rich as hell.

Then I get called an internet tuner for telling them how stupid they really are.

Go figure.

 

This is exactly what I did. I read countless threads on here since 2006 and pm'd a handfull of people and 90% said to "Keep it safe...run it rich and add a little timing the car will respond better ect." I was even "educated" on the 160* thermostat = more room for timing thing. Not saying that is not possible, but G over at Nitrous outlet was the first to tell me to pull some timing and a little fuel and see how it responds and go from there. I went from 11.50 to 11.40 1/4's just by doing that...But I still wasn't completely sure that was "safe". So I added some fuel back before I left the track. On the way home the car felt sluggish, so I pulled over and added more timing back in. Basically, I did what G said, but I didnt understand why I was doing it...until ATVrcr made it clear. It's like a light came on. Hopefully with the new knowledge gained I can tune my girl and get some 11.2's out of her before upping my shot.

 

yup.... this argument was going back and forth on yellowbullet for years!!!! Between tuners, racers, benchracers, nitrous companies, etc.....

My car AFAIK doesn't like that much timing. We had the tune spot on for the 350 shot as far as i was concerned. Car was putting up BIG MPH numbers and the plugs looked pretty good. Was going 122 in the 1/8th and 154 on the big end at 3400 lb raceweight. We upped it to the 400 shot (225 1st stage and 175 turned on .5 later).... Car slowed to a 9.11@152. Took out the grounding strap on the #2 cylinder....

Now admittedly I am limited when it comes to cylinder to cylinder tuning. I don't have a cam sync therefore i can't utilize the XFI fuel trim for individual cylinders. Since I run a 2 stage dry plate my distribution of nitrous cannot be trimmed by jetting up or down different cylinders. So I think that is where my limitation exists. I think the only way we'll get to where we want to be is by going to a fogger AND putting a cam sync in to trim individual cylinders. I'm sure that we took out the grounding strap on the plug cause we were overtimed most likely. but all the other cylinders looked fine and the plugs were good...

So since we have the 350 shot tune down for my motor we're now going to start attacking the other enemy slowing us down: weight. 3400 lbs is just too heavy for what we are trying to do. I can always up the nitrous but ultimately my LT1 was never designed to make 1100-1200hp. And 23 degree heads and 383 ci will only go so far.... But ATVracr's advice will work on any motor. My car was making great power at about 12.4:1 AFR. We toyed with the idea of going leaner but never got the chance after she took that plug out. We thought we lifted a ringland but upon motor teardown Nope... piston fine....

 

The first time I saw ATV say they took fuel out their motor and backed off the timing and it went faster I thought he was crazy. This was about 8 months ago.

Since then I have done a lot of research and tuning on my old turbo car. I was running it at 10.8-11.0 AFR and 16* timing at WOT. This was on 15psi and methanol injection 100% M1 and 50/50 93 pump and 110. I had no knock so I thought I was fine. Boy was I wrong.

My plugs were so black and fouled it wasn't even funny.

I ended up leaning it out to 11.4 and backing the timing down to 14* after I ramped the timing down from launch. (I had the timing set higher to build wheel speed and as boost came in I retarded it). The car went from 106mph to 108mph. I then leaned it out some more to 11.7-11.8 and it went 110mph! I then got a little ballsy(or so I thought at the time) and added a gallon of C16 on top of the 50/50 93 and 110 I had and leaned it out to 11.9-12.1. The car went 112mph and I got my best e.t. ever along with it(6.50's IIRC).

I finally had some heat in the strap and I had a timing mark also where as before it was so over fueled it wasn't showing any heat and I couldn't see a timing mark so I had no idea if it was under or over timed.

It's amazing what actually thinking some things through with common sense will do for you.

Good luck with meeting your goal and honestly I don't think a 10.90 is out of reach for you

 

Awesome! Thanks, I'm not arguing I'm asking this. But why add timing instead of pulling more? The least timing without mph falling off is best right?

 

Not sure if you have looked into these things or not but before we had the XFI we could not tune ind. cyl either so we played with Plugs and injectors.

Have your injectors flowed and put the ones that flow the most in the hottest holes. (would be 7&8 for LS1)
Not sure what plugs you are using but you can also put colder plug in the hot hole.
When those are not enough you just have to tune to the hottest hole.

Good luck !

 

Most people think a rich mixture is a must with nitrous.
It's the old school way of tuning nitrous, most kits come over jetted for gas from factory, so people think it's the way to go.

I always start at 12:1 AFR and retarded timing, then I lean it little by little and add a few degrees until I see max power.
Most engines I've seen like between 12.5 and 12.8 AFR, timing varies depending on heads and CR.

If you have something wrong an AFR of 9:1 isn't going to protect your engine.

My way of thinking is: If the engine likes it and makes more power, you are doing right and you can give it a little more. Always use small increments and change only 1 thing at a time then do a test run.

 

Who said to add timing?

 

Yeah we're using -11 plugs so they are plenty cold. We were using 10's for awhile until we went to a 300+ shot total... the injector flowing we hadn't done but that's pretty interesting...
we'll have the motor back from the shop again soon so we'll probably try that....

But right now i'm trying to lose about 300lbs. no sense in adding more power to an LT block already making 3-4 times the original power it had...

I figure a weight drop of 300+ lbs is the easiest way to lose 3 tenths....

 

Good stuff.
On the plugs maybe try running 10's in most of the motor and 11's in the 1 or 2 hot ones. Just an idea if you run out of other options.

 

Sounds like you are at the point of your nitrous usage where you either need to stagger plugs as ATV has suggested, stagger injectors, or have the chambers softened to allow a little more timing lead and/or go to an ICT set-up with a two stage fogger.

 

sorry to pull up a thread that is over a month old....

I have a 408 that I sold the twin turbo off of and am changing pistons and going with a direct port 300 shot. CR should be around 11.5-12 and I will be running a stand alone with C16 in it. I still have a methanol kit and may be using that in addition to bump the octane NA.

My question is what plugs would be good to run. I am guessing I should be around 500rwhp give or take NA and was thinking br6ef.....and then for the 300 shot several ranges cooler. I have had issues with 5 and 7 and hince the rebuild. ALso wondering if I should put a colder plug in 7 and 8 like suggested?

 

300 shot on a healthy 408 I would start with 11's in the whole motor so you can see what it needs and go from there.