2 step, not building boost off the line?
11-28-10, 01:57 PM
#1
2 step, not building boost off the line?
Ran my car last night. And I noticed I'm not building boost at the line with the MSD 2 step. The rev cut was at 4200 rpm. Which is not that high, but its a stock S5 TII turbo. With that small of a turbo, I should of built some boost...
Any ideas?
My only guess would be that it's creating to much back pressure and forcing the stock waste gate door open prematurely. Similar to what happens at high RPM causing boost to drop off.
Any ideas?
My only guess would be that it's creating to much back pressure and forcing the stock waste gate door open prematurely. Similar to what happens at high RPM causing boost to drop off.
11-28-10, 07:13 PM
#3
It never built boost for me. I tested it a few times in the driveway, but with a crappy restrictive filter on the intake for daily driving. So i figured that had something to do with it. When I put on the velocity stack with no filter, i figured it would build some kind of boost, but still nothing.
The 6al is wired to the leading coil, 2-step plugged into that. Then two solenoids shutting off the trailing coils when the 2-step activates. It works great, it just dosnt build boost.
The 6al is wired to the leading coil, 2-step plugged into that. Then two solenoids shutting off the trailing coils when the 2-step activates. It works great, it just dosnt build boost.
11-28-10, 09:17 PM
#5
Yes it holds RPM with my foot to the floor.
The highest RPM I have tried was 5k. Which should be more than plenty to give some boost on the tiny stock turbo. Even if the stock waste gate is opening prematurely, it should still make some kind of boost. I doubt the stock internal gate is large enough to release all the exhaust pressure without giving any boost...
Maybe because I'm not running open downpipe? or I'm still on the stock ECU, and the AFM before the turbo is to restrictive to feed enough air?
The highest RPM I have tried was 5k. Which should be more than plenty to give some boost on the tiny stock turbo. Even if the stock waste gate is opening prematurely, it should still make some kind of boost. I doubt the stock internal gate is large enough to release all the exhaust pressure without giving any boost...
Maybe because I'm not running open downpipe? or I'm still on the stock ECU, and the AFM before the turbo is to restrictive to feed enough air?
11-28-10, 10:08 PM
#7
I do have a stock turbo manifold that I modified for an external gate. I think it's time to install it and see if it helps out. Also (hopefully) I'll be able to hold boost all the way to my shift point instead of it dropping off hard.
My goal is to run 12.99 or better with the stock ECU, turbo, and motor, ect. After that, I'll upgrade from there.
I ran a 9.3 at 81mph in the 1/8th 1st time out with the car and it had suuuper bald tires. I mean dangerous to drive on bald tires. I have a set of slicks and skinnies on a Weld Prostars. But I wanted to test the 2-step in the 1/8th before I go all out with slicks on the 1/4.
Here's a shot of the external gate on the stock manifold.
My goal is to run 12.99 or better with the stock ECU, turbo, and motor, ect. After that, I'll upgrade from there.
I ran a 9.3 at 81mph in the 1/8th 1st time out with the car and it had suuuper bald tires. I mean dangerous to drive on bald tires. I have a set of slicks and skinnies on a Weld Prostars. But I wanted to test the 2-step in the 1/8th before I go all out with slicks on the 1/4.
Here's a shot of the external gate on the stock manifold.
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11-28-10, 10:34 PM
#9
i ran a 8.8 in the 1/8th with stock s4 turbo/top mount/ecu, just the usual intake/exhaust/12 psi.
you should have no trouble getting there. even with out the two step, i mean, its just cheating anyways aint it, who needs a two step on a stock turbO .lol
you should have no trouble getting there. even with out the two step, i mean, its just cheating anyways aint it, who needs a two step on a stock turbO .lol
11-29-10, 03:51 PM
#10
Right now I only have a Manual boost controller hooked up. I have an electronic boost controller, I just havnt installed it yet. I'll see how the external does first before i hook up the EBC.
Most of the time I'm only at 6psi. but it spikes to 10psi for just a moment. It's breaking up pretty hard in 1st. And after watching the videos of my runs, the car sounds funny. I have a SAFC NEO hooked up, I'm just waiting for my wide band to come back from Innovate (burned out) to do some tuning.
12-14-10, 02:06 PM
#11
Update:
I installed the external dump on the stock manifold with a Turbonetics 38mm deltagate mark II. Builds boost off the line now! Sounds so dope, lol...
Also I can hold boost all the way with no problem now. 20 year old stock internal wastegates suck.
I installed the external dump on the stock manifold with a Turbonetics 38mm deltagate mark II. Builds boost off the line now! Sounds so dope, lol...
Also I can hold boost all the way with no problem now. 20 year old stock internal wastegates suck.
12-18-10, 07:47 PM
#14
when i hooked up my crane ignition with 2 step, it would not build boost until i raised the limit up past 5k. at 7k it would build only 5 psi, stock turbos non sequential. that didnt seem like much, so i retarded some cells in the timing maps in the cells used when bouncing off the 2 step and added more fuel in those cells and now it bumps up to 10psi. how much boost does yours build? and do you get any flames? haha, I dont, little disappointed after seeing all the cool 2 step youtube videos haha
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