New motor + 70 turbo = downpipe hitting

[BLACK6PACK]

Those of you who are running a 4" inlet large turbo, how do you get the THDP to clear the heater box? The THDP on my brothers car hits the box and I think its causing some serious false knock. One time it will run ok, the next it shows 30* of spark retard, but not hearing any knock. This is on 118 octane 18 lbs of boost and 23* of timing. They just dropped the motor in, and are trying to sort out the bugs.

Another problem is that they get to about 16-18 lbs of boost and the car just noses over. It has an extreme extender, translator plus, ls1 maf, full roller motor, m&a heads etc. He says it sounds like the blowoff valve is bleeding off all the boost once it hits about 15-18 lbs, problem is there is no blowoff valve. My buddy is trying to get it running decent before taking it to Lonnie Diers so he can get her running perfect. He has all the settings somewhat rich, and it will show 850s on the scanmaster and will show as low as 10.5-1 on the WB02. I'm thinking the 2nd fuel pump is kicking on at 10lbs and drowning the motor causing it to nose over.

Any input would be appreciated.

 

[badboy86gn2]

I have a 4in inlet turbo and the thdp hits but not to the point it causes knock hmmm try if you have to opening up the bolt holes a LITTLE and put something between the dp and the heater box so they dont rub then tighten it

as for the nose down see if all the turbo intercooler hoses are tighten sounds like boost is escaping somewhere

Johnny

tell lonnie Johnny in albuquerque said hello

 

[Real-T]

Have you removed the metal shield that goes around the heater box ?? That can open up a little bit of room enough for the DP.

 

[slimtastic]

also if your motor mounts are old, the engine could be turning over a little too much causing the thdp to hit stuff. hope this helps

 

[norbs]

Lose the stock ecm and get Lonnie to put a Gen 7 on it, you can turn off the knock sensor at a certain rpm/boost.

 

[BLACK6PACK]

My brother just spent a small fortune on the Translator +, maf, and commander chip. He's not ready to be running a DFI type system. I think the Commander has a knock ignor feature on it. I don't think it would be a good idea for him to turn the knock sensor off. He's going to have $10,000+ under the hood once all is said and done.

It has brand new HR mounts on it.

Thanks for the input. I'm 1200 miles from the car, so I can't help much, and I'm trying to get a couple of guys who aren't TR guru's to explain to me exactly what is happening. I'm sure Lonnie will get it straitened out. I'm just trying to get it running decent before lonnie gets his hands on it, so that he's not chasing bugs and instead can spend his time tuning.

 

[DonnieShort]

What headers are you running?

 

[Nojug]

Your going to have a hard time using the knock sensor in a motor with a roller cam the easiest thing to do is unplug it and save yourself the trouble. My motor will pick up false knock at an idle.

 

[SYTECH]

Roller Cam & Double Pumper

I agree with the recommendation about the roller setup causing false knock, unplug it and be careful with your tuning.

I also think you might want to consider having the 2nd fuel pump come on sooner (all the time) and work the excess fuel back out of the equation with your tuning efforts

I have an ATR Double Pumper in my 86 GN and when I had it in for some dyno / FAST tuning recently, the tuner could not understand why the power was dropping off and the car was going pig rich at a certain boost level (until i told him about the double pumper)

He adjusted the Hobbs switch to put the pump on all the time, worked the fuel out using the FAST system and the power curve straightened out real fast

Car went from 398 rwhp at 14 lbs of boost (91 octane gas) all the way up to 425 rwhp at 14 lbs of boost (91 octane gas)

I can't wait until I do some tuning at 20+ lbs of boost with some good gas to see what this engine can really do

Good luck

Ray

1986 T-Type / WE2 / stock block, stock crank, stock rods, stock pistons, Champion aluminum heads, roller rockers, roller cam (210/210), 70 mm TB, GTQ71 turbo, 75 lb injectors, FMIC, 3600 stall convertor / FAST system