Turbo - Bender 2 - falls on its face past 2/3 rds throttle

[77srxdude]

I installed it two years ago and it ripped right from the beginning - 15lbs - 124 mph (more than gearing was suppose to allow) on GPS and I put 1000 + miles on it until one day when I was out of race fuel/93 mix and stupidly I ran it too hard.

Rebuilt with low compression pistons.

Put it back together with all settings the same. 500 jet in the Pitot tube. Stock jetting in the carbs and a Hallman Boost controller that has 14 full turns and I have it turned in 8 turns. Rebuilt it at the end of that season and rode it 1 time and it wasn't right but put it away for the summer to work on it later.

I got into ice oval racing the next year and it sat all year and never ran it. This year I just got it out to run for a few days in Michigan. I pulled the carbs, removed all the jets, cleaned them throroughly with mini pipe cleaning tools, flushed the tank of old gas and put in a 1/2 mix of 93 non-ox and 110.

It still did the same thing as after I rebuilt it - If I put the throttle to the bar, she falls on her face and spits and pops real bad. I tried a leaner pitot to 740 and it barely helped. If I run 1/2 to 2/3 throttle it picks up fine and builds boost to a point - I can get 8 lbs on the guage (with my controller turned all the way out - if I turn it in, everything gets worse) but it feels like it is running on maybe 4 lbs. IF I go past that 2/3 rds, it spits and pops. Almost like it will build boost so far and then just give up.

I found one of the little o-rings in the top of a carb missing, replaced it, didn't help. I have the billet tee's, checked the connections and bender box for cracks, can't seem to find anything. Haven't pressure tested yet.

I was told I need to go leaner with low comp pistons but would it really make it act that bad?

My suspicion is a leak somewhere but I am curious as to what the experts think. Should I try lower mains first?

Thanks in advance for the help, I have read a lot of threads and haven't seen anything quite the same.

Forgot to say - it is an 05 RX1, does have a BOV located shortly after the Pitot towards the intercooler.

 

[Ted Jannetty]

Re: Turbo - Bender 2 - falls on its face past 2/3 rds throt

I installed it two years ago and it ripped right from the beginning - 15lbs - 124 mph (more than gearing was suppose to allow) on GPS and I put 1000 + miles on it until one day when I was out of race fuel/93 mix and stupidly I ran it too hard.

Rebuilt with low compression pistons.

Put it back together with all settings the same. 500 jet in the Pitot tube. Stock jetting in the carbs and a Hallman Boost controller that has 14 full turns and I have it turned in 8 turns. Rebuilt it at the end of that season and rode it 1 time and it wasn't right but put it away for the summer to work on it later.

I got into ice oval racing the next year and it sat all year and never ran it. This year I just got it out to run for a few days in Michigan. I pulled the carbs, removed all the jets, cleaned them throroughly with mini pipe cleaning tools, flushed the tank of old gas and put in a 1/2 mix of 93 non-ox and 110.

It still did the same thing as after I rebuilt it - If I put the throttle to the bar, she falls on her face and spits and pops real bad. I tried a leaner pitot to 740 and it barely helped. If I run 1/2 to 2/3 throttle it picks up fine and builds boost to a point - I can get 8 lbs on the guage (with my controller turned all the way out - if I turn it in, everything gets worse) but it feels like it is running on maybe 4 lbs. IF I go past that 2/3 rds, it spits and pops. Almost like it will build boost so far and then just give up.

I found one of the little o-rings in the top of a carb missing, replaced it, didn't help. I have the billet tee's, checked the connections and bender box for cracks, can't seem to find anything. Haven't pressure tested yet.

I was told I need to go leaner with low comp pistons but would it really make it act that bad?

My suspicion is a leak somewhere but I am curious as to what the experts think. Should I try lower mains first?

Thanks in advance for the help, I have read a lot of threads and haven't seen anything quite the same.

Couple things to check

Cap the turbo inlet and pressure test the charge system, that is everthing from the turbo inlet to the intake valves, you might be surprised how many leaks you have just disregard the Pitot jet.

Cap the exhaust pipe and pressure test the exhaust system.

Pull the turbo and check the exhaust housing for excessive Rust and for Rusted wastegate, if stuck closed or binding the sled will overboost and fall on its face as you described.

Spark Plug Gap should be 0.024 and fresh plugs.

With coil in hands test fit spark plugs in coils for nice tight fit on the threads.

By pass TORS.

Check fuel pressure running and under boost should be 4 psi, and go up 1 psi for every psi boost.

Any chance the pressure regulator boost hose is off, you will find this with pressure test.

You can also check the fuel pressure rise with fuel pump running and pressure test on charge system.

Carefully check fuel pump and relay connections I found a few Bender kits with lose connections here.

Let me know the results of above tests.

Ted.

 

[77srxdude]

Thanks Ted - I will check those.

Man would it be nice if it was something as simple as the TORS - I know I have never unhooked it - even when it was running well.