hey john it misfired under heavy load so here is the story
friday morning in october take a customer for a ride get on it and blow the clutch order a clutch from dan at vivid install it sunday taking it out for a 60-130 run sunday eve pull a 7.1 nice ok get off the exit turn around start to head home on the eway in 4th gear around 3k rpm start to open the throttle up 3/4 boost start to build (peaked in the low 1.3 range) then i here this sound (kinda like breaking a motor mount on a muscle car fan hitting the shroud) this all happend in about 3 seconds let up on the throttle take it easy on the way home pull into garage here awful ticking porsche tech comes to house says bring it in he pulls motor 5&6 both bent i think it was a combo 93oct/misfire 35F airtemp and just too much air in the cyl who knows it runs great now but i am gun shy now only running .8 bar on 104 oct

tim

 

[quote=joetwint;1602953]+1 it was a series of unfortunate events

 

John-

How does your setup run on pump?

 

you probably had burnt the head gasket on the last run and got some coolant in the cylinders........the plugs got wet and misfired and then came the bent rods from not being able to compress the coolant.A misfire alone should not bend rods .

 

Adam,

My car runs awesome on pump - that's all I use, except for the couple of times I go to the track each year. I run Sunoco 104 when I do 1/4 mile runs.

I set my EBC to boost about 1.18-1.19 and the car has plenty of power - feels like a rocket! I up it a little at the track, but not over 1.3 - I think I was running 1.28 at the track and my fastest 1/4 mile pass run was at more like 1.24

Personally, I do not notice much difference between 1.18 and 1.28

 

John,

My understanding is that octane rating refers to how easily fuel ignites and burns. The lower the octane, the easier it is to ignite. Lower octane fuel actually makes more power, but is less resistant to detonation (is more likely to prematurely combust) under high pressure.

This is long but very informative

http://en.wikipedia.org/wiki/Octane_rating

As you already know, turbos significantly increase the actual compression that air sees by packing a lot more of it in. They also introduce a lot of heat. Both of these increase your chance of detonation.

 

It is quite simple in fact, low octane fuel rating will cause knock at lower boost levels, and also potentially damaging detonation. Rods are not bent as a result of excessive torque, they were bent as a result of detonation. Poor mapping for the fuel and boost you were running is the most likely response.

The EBC in itself not allowing boost to be pulled back, or the boost level itself is not really the issue on a standalone basis, it is the whole combo that was not good, namely mapping, assuming the engine build was good and mileage not excessive. If you are sure that your boost did not go beyond 1.3 bar, then I would ask for explanations.

 

Well now I am wondering what to do??? I have the proto 24-18g turbos with upgraded wastegates and 5Bar, but I am leaning to NOT install the Greddy. I live in CA and run my car on ****ty 91 octane (I am in an isolated area in N Cal). I would like to have my program boost 1.1 bar without EBC. Will this insure no over-boosting and will the ECU pull timing above this threshold. I drove a simular turbo at 1.1 bar and it was crazy fast and plenty fast enough for me and I know I would leave another 50HP on the table at 1.3 Bar. I will call Todd and ask him. What do you guys think.

 

How bout a custom tune using the stock boost solenoid. PM me for information. GL

Suman

 

The Greddy has a built in warning limiter in case you go over the set amount of boost. It can pull as much as 10% of boost out to ensure safety.

Mitch

 

Mike,

You do not need to use a Greddy with Todd's turbos - he can set yopu up without a Greddy.

Mitch,

Don't you mean 100%? I am pretty sure I have mine set to reduce by 30%, if I hit the limit.

 

Hmm. I thought it was only 10%. Could be wrong. It happened once before.

Mitch

 

I agree 100%...@1.3 bar there shouldn't be issues even with pump gas! IMHO

Tom

 

Todd can set up up without the greddy... but you will leave extra HP on the table if you ever want it. Im not sure what the big deal is running a Greddy. I have one on a 850 rwhp and Im not worried.. yet you guys with 500 rwhp are worried

I also have on on my Evo with 780 hp and its the best thing to have if you know what your doing...

markski

 

Guys, its REAL simple...don't run too much boost for your gas. And have your car properly tuned. Todd hand tuned my car. I run 1.2 (tops,) on 93, 1.4 on race gas (112).