Tuning

[GOT JCE]

My first run with the GN after all the mods were done was very disapointing.My best run was 13.55 at 98mph.With all the mods I put into it I was expecting a high 12 second time.My mods were as follows:3" dp,walbro pump with hot wire kit,adj wastegate,razors alky,36lb injectors,TT alky chip,accufab fpr,275/50-15 MT drag radials,cold air kit,scanmaster,stock exhaust.The fuel was set at 42psi my first 3 runs and had no knock at all at 18lbs of boost.I kept the same fuel pressure but increased the boost to 20lbs and went slower.The car felt like it was being held back and just fell flat in third gear.Car was backfiring.Still no knock and the O2 was around 800.I had to leave the track when my wife called hysterical that our son had a temp of 104.5 and was having seizures.So I made the 2 hour trip to the hospital.The car idoled like crap the whole way home.I found when it backfired it blew the screens off the maf sensor.I replaced them and now the car idols fine but if I put it to the floor it still backfires and runs like crap.The car really feels like it is being held back.I think the exhaust might have something to do with it but what fuel pressure should I start out with?Any advice is greatly appreciated.Thanks,AJ

 

[GOT JCE]

I forgot to mention my 60' times were 1.7-1.9 better than I expected my first time out.I left on the brake with 5lbs of boost.Came out of the hole great!!!

 

[vader87]

First check all vacume lines. If one is off, you will have issues. Second check cam sensor. It may be cracked or 180 out. Check all the spark plug wires. Does your fuel pressure go up when you go into boost? There are better experts on this than me and I am sure they will jump in here and help. Good Luck and I hope your son is doing better!

 

[GOT JCE]

I checked the vacuum lines and replaced a few of them.When the car backfired it blew off the one that runs above the drivers side valve cover.After replacing them I still was having trouble.I will check the cam sensor next.Thanks and my son is doing great.

 

[GOT JCE]

I checked the vacuum lines and replaced a few of them.When the car backfired it blew off the one that runs above the drivers side valve cover.After replacing them I still was having trouble.I will check the cam sensor next.Thanks and my son is doing great.

 

[22lbChevelle]

Some backfiring, or the popping could be due to a rich condition... OR it could be that your plugs are fouled or gapped improperly. It takes less gap to fire more boost along with the alky.

 

[GOT JCE]

Update

I was bored at work and went out and tinkered with my car.I raised the fuel pressure to about 46 psi and now the car runs much better.Launches nice and hard and does not bog down now and stutter.I will be adding an A/F guage to fine tune this thing.I can't believe it was starving for fuel.No knock at all even though it was running lean and than adding methanol.I will ask Julio for some tuning advice.Thanks guys.

 

[Silver Fox]

I was bored at work and went out and tinkered with my car.

Are there any openings at your job?

 

[NHRA Super Gas]

Are there any openings at your job?

This made my day!

Now that your son is better, take the car back to the track and let us know what you've got!

 

[GOT JCE]

Job opening

Sure if you like making a lot of money for sitting at your computer while taking care of drunk welders at 7am and then spending that money on your turbo buick that won't get out of the 13's then yeah it's a great job.I love doing burnouts in front of my shop and doing 1/8 mile runs for lunch.I just wish there were some hot female welders out there who would brighten my day looking for some rod.HAHAHAHA Thanks for all the concern about my son.I really appreciated that.My wife was so happy I got there so fast she said I can go to Englishtown in a few weeks.God bless her.

 

[87GNSteve]

Check your ignition coil also, can cause back fire when hot...and backfiring can harm a coil that worked fine also.

 

[flattype]

If it was really hot and humid that will explain poor times. I had a 03 cobra and it was much slower in hot weather.

 

[87geeinn]

That seems pretty normal. Your only significant mod that you have is alky and a cold air intake. You aren't really pushing the envelope all that much. I run 17# boost on 93 with no knock and your only running 20# with alky. The sticky tires no doubt help. Your running a 3" dp through full exhaust which isn't going to help much, if at all because your not flowing enough air to make a difference. The rest of your mods don't add power, rather they are supportive mods, meaning that they provide the monster the means to deal with more power.

 

[Paul Clark]

I admit my ignorance, but if you had a 1.7 60' (I'm jealous) and still ran in the 13's at 98 MPH, I'd be concentrating on the top end charge.
With your chip you can adjust the timing in the 2 top gears.
Those who know much more than I will tell you whether or not that might help.
Also, believe that that the hose you blew off hooks up to one of the hard lines that goes to the EGR stuff. Realize you probably don't need it with your chip, but it might help you backtrack to the problem.