Orr89RocZ

iTrader: (20)

Deleted the cat converter and replaced with a straight section pipe. Tightened plug gap to .025 over the previous .035" and it liked it!




10 psi boost.

It made 5-6 by top of first gear. 9-10 by top second and top third hit 11 psi but was 10 through the pull.

I tried 14 and 16 psi but ran identical. It does not like more boost, my guess ignition system cant light this off. I dont think i have boost leak or anything.

But goal is accomplished. 110 mph shows good power. Where i hoped it be. Needs torque converter and ignition system it should be a low 12 car easily

Orr89RocZ

iTrader: (20)

Crappy incar vid off my phone lol didnt focus well but can get an idea of the boost response

aliceempire

iTrader: (14)

Beautiful. Sometimes I wonder why I stay NA.

jimw67

Could you feel the spark being 'blown out'? I am concerned that I have the same issue, but I don't know what to expect if and when it happens. The run in the video seems like a strong, smooth pull. Were the other two pulls similar, just not any more speed?

Basically, how will it feel when the spark isn't strong enough for the boost?

Orr89RocZ

iTrader: (20)

My black car felt this way as well.

Car felt exactly same, ran exactly same, and air fuel looked near same lol

10, 16, 14, 15 psi runs this weekend this car didnt feel any different. My first outing with this car on 7 psi it went 98 mph i think. 15 psi running 10.5 air fuel went 14.3 at 97.

All i did was replace plug wires and tightened gap, deleted cat with straight pipe but i doubt this had anything to do with it. 10 psi went 110 mph no changes to tune. Plug gap had to help

My black car didnt seem to pull as strong up top. More boost did go alittle more mph but was curious why it seemed to fall off. Tighter gap didnt do much but what did was increase spark dwell or basically energy of spark. My air fuel went from 11.4-11.5 to 10.5-10.6 and i had to lean car out. Dropped alot of fuel and started trapping mid high 160's with a much smoother rpm log

Next real test will be ignition system on this car. Could use a new dizzy cap and rotor i bet too. I want to see this car go 115+

jimw67

Keep us posted as I'm extremely curious of how this works out. It seems to me that your issue isn't spark, but rather some type of air restriction such as the intake can't handle more air, the turbine is creating to much back pressure and it's backing up into the cylinders, or your exhaust is not allowing the turbine to exit enough air. If I had to make a guess, I'd say it's the turbine causing too much back pressure, but this is my GUESS, emphasize guess.

I have something similar going on and I'm trying a different cam. What your trying is a tad bit cheaper than what I'm trying, but perhaps we are both correct or incorrect. Maybe it's the TPI that just won't flow any more air, but I don't think so due to increased mass of air as the boost increases.

Again, based on my common sense, it would seem that when the spark gets blown out that there would be a serious loss of HP, TQ, and speed, but what the hell do I know (that's why I accurately refer to myself as a novice). Over the winter I'm going to install a pressure gauge in the crossover to see if the flat spot happens at some certain amount of backpressure. And also install a pressure port pre CAC to see what kind of pressure loss I have there as well.

As you can see, I have alot of guesses, but no proof. Again, keep us posted and thanks.

Orr89RocZ

iTrader: (20)

I'm just gauging the performance changes between my race car and my buddys 7 sec car. We both had similar issues on high boost. He switched to a hotter coil pack and increased spark energy. Picked up 70 hp on dyno immediately, no other changes. Car pulled down track better.
Mine immediately richened up when i increased spark energy. ran similar mph but whole point richer. Once i leaned it out it really hauled the mail. Datalog in third gear showed much smoother rpm line. Its not really blow out but rather incomplete ignition. Only some of the mass is being burned off. Just a theory, i cant otherwise explain why my car did what it did

This 305 only started to run strong after wires and plug gap change. Now i gotta figure out what to try next. May check cap and rotor. Really want to borrow my friends msd 6al

If that works we will know.

I dont believe tpi is a restriction. There are guys faster than this out there using tpi based stuff

I also dont think the turbine is limiting anything and was going to back down to a .68 housing to quicken spool lol. This car is lucky to break 300 whp right now. I have made 500 thru these turbos before as set of twins. There should be plenty of room. Maybe the manifolds dont help but i dont wanna fab a shorty header or buy a set just yet

I'll keep you posted

RBob

iTrader: (1)

Have to admit, gaining 25 MPH on the big end shows that the engine is making power. Get it to spool a little faster and it's easily in the 12's.

RBob.

Orr89RocZ

iTrader: (20)

Yeah hope to get a converter in it for next spring. But fear the tranny is on its way out with this power lol

Still would like to go ebl on this deal but for now code $59 is in place

DIGGLER

iTrader: (1)

Boy, this sure does sound like my friends problem of not picking anything up over 10psi..... he was running holley efi with stock ls coils with some long plug wires. Plugs were gapped pretty dang tight.

Orr89RocZ

iTrader: (20)

Yup. Kinda does. We are still trying to figure things out. My buddy wants to try either new valve springs or go solid roller. Also should try a backpressure readout

My black car i think could use alittle more spark energy and timing but will have to wait til next year to play with all that

Blue car i just dont think stock ignition system can handle it. Doubt its valve float but if so i am doing a nice cam and having heads cleaned up with new valve job

jimw67

You mention long plug wires. Are you implying that might be an issue? I ask as I have 3 on the passenger side that run to the front of the motor and then to the plugs. Saying they are long is an understatement.


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From what most everyone is mentioning, the phrase 'blowing out the spark' doesn't imply a no spark condition, but rather a weaker spark or a spark that won't ignite all of the fuel cleanly - correct?

DIGGLER

iTrader: (1)

Well, I remember people having trouble running stock coils with the holley efi, and thats the setup my friend has. And, he has the coils out away from the engine which meant he needed long wires. Short wires have less resistance than long, so a smidge less energy would make its way to the plugs as opposed to the short stock ls wires. Enough to make a difference? I dunno?

Orr89RocZ

iTrader: (20)

Correct. I think its too weak. Thats the only thing that would explain why i had to lean out so much after the change in spark dwell. You can sometimes feel it on the top end, like constant hesitating pulses and not a smooth pull