taking too long to build boost on t-brake re-stall converter?
05-29-2012 | 10:13 AM
#21
That cam would be a lot better if it was on a tighter lobe, but the split looks ok. AS phil said install it 6 degrees advanced it will help move more exhaust gas into the turbine helping it spool.
05-29-2012 | 10:22 AM
#22
In the video posted above from 9 - 11 seconds in the video, it spools very fast. So your setup is fine, converter probably needs to be tighter as fast as it comes up.
If brakes are your issue, put either better cold pads on it or dual calipers or move the ratio on the arm. My car is like 7.5 to 8:1 if memory is correct.
Problem is your stating the problem is spooling but the problem is its pushing through the brakes.
If brakes are your issue, put either better cold pads on it or dual calipers or move the ratio on the arm. My car is like 7.5 to 8:1 if memory is correct.
Problem is your stating the problem is spooling but the problem is its pushing through the brakes.
05-29-2012 | 03:14 PM
#23
Don't you think the bump box would be a good idea too in lieu of the brakes?
He could pull in the first beam, press and hold his trans brake button and build whatever boost he needed, then while holding his transbrake button tap the bump button to set the car in the second beam.
I didn't watch the video till just now and it does come up pretty quickly, but if you're having trouble holding it there on the service brakes, the bump box might be your best bet. I would of loved to of had a product like this a year ago.
He could pull in the first beam, press and hold his trans brake button and build whatever boost he needed, then while holding his transbrake button tap the bump button to set the car in the second beam.
I didn't watch the video till just now and it does come up pretty quickly, but if you're having trouble holding it there on the service brakes, the bump box might be your best bet. I would of loved to of had a product like this a year ago.
05-29-2012 | 05:05 PM
#24
Ive been told by Rossler Trans my builder not to use the bump box, for they dont know what it could do to the tranny. I dont have the money for stuff to break but it does sound awesome. And really? yall thought that came up on the high chip fast? its like 3 seconds in those videos how do you even spool that in time for a pro tree?
When I get the turbo rebuilt by Precision ill data log a TB pull and set the timing at 37-38 or so instead of the 25 my tuner had it at, 2,200 all the way till 3500 rpms when the boost starts coming on and can resume regular timing from that RPM untill the 3 step hits. That and can you make a back pad reccomendation? I know jack about brake pads. Like ZERO. The other oddball thing is with this new setup my brakes are rediculously touchy.. like the pedal isnt super duper hard no matter how I bleed it but if Im going very slow it takes zero pedal effort to almost lock the brakes up. IDK i have 100 % stock brake system with the booster and just an SJM Abs delete kit
When I get the turbo rebuilt by Precision ill data log a TB pull and set the timing at 37-38 or so instead of the 25 my tuner had it at, 2,200 all the way till 3500 rpms when the boost starts coming on and can resume regular timing from that RPM untill the 3 step hits. That and can you make a back pad reccomendation? I know jack about brake pads. Like ZERO. The other oddball thing is with this new setup my brakes are rediculously touchy.. like the pedal isnt super duper hard no matter how I bleed it but if Im going very slow it takes zero pedal effort to almost lock the brakes up. IDK i have 100 % stock brake system with the booster and just an SJM Abs delete kit
Last edited by z28boysteve; 05-29-2012 at 05:18 PM.
05-29-2012 | 08:25 PM
#25
Do this.
Instead of adding the timing in the main timing table, add the timing in the afr spark correction table when the engine is commanding the afr you see on the footbrake.
Say your using a multiplier of 1.0-1.12 from 20 kpa to 100kpa in your open loop fuel adder table(this is an example your multiplier will vary) in your engines coolant operating range(usually 174-212).
In this table (afr spark correction table) it adds spark when the pcm commands a fuel multiplier to equal the afr you want. So when you are on the footbrake fighting to transition from vacuum to boost and your pcm is commanding that 1.0-1.12 multiplier from 1200rpm-4400rpm have it add 10-12* of timing.
That way when your on the footbrake transitioning from vacuum to boost and the motor is in that afr range that 1.0-1.12 commands it will add that amount of timing to what your timing is at that rpm in the main timing table. Obviously your pcm commands a much richer multiplier under any kind of boost so it won't add that timing when it's under wot or anywhere below or past that multiplier.
This really helps to get a stock pcm car to spool. Play with it some, you might find you can keep the timing in it later to a richer multiplier depending on the fuel you are using will determine how long you can keep it in. I wouldn't keep it in past 3-4psi because by then you got the turbo working for you and not against you.
Hope this helps.
Instead of adding the timing in the main timing table, add the timing in the afr spark correction table when the engine is commanding the afr you see on the footbrake.
Say your using a multiplier of 1.0-1.12 from 20 kpa to 100kpa in your open loop fuel adder table(this is an example your multiplier will vary) in your engines coolant operating range(usually 174-212).
In this table (afr spark correction table) it adds spark when the pcm commands a fuel multiplier to equal the afr you want. So when you are on the footbrake fighting to transition from vacuum to boost and your pcm is commanding that 1.0-1.12 multiplier from 1200rpm-4400rpm have it add 10-12* of timing.
That way when your on the footbrake transitioning from vacuum to boost and the motor is in that afr range that 1.0-1.12 commands it will add that amount of timing to what your timing is at that rpm in the main timing table. Obviously your pcm commands a much richer multiplier under any kind of boost so it won't add that timing when it's under wot or anywhere below or past that multiplier.
This really helps to get a stock pcm car to spool. Play with it some, you might find you can keep the timing in it later to a richer multiplier depending on the fuel you are using will determine how long you can keep it in. I wouldn't keep it in past 3-4psi because by then you got the turbo working for you and not against you.
Hope this helps.
05-29-2012 | 10:07 PM
#26
thanks dude I might have to get with you soon to figure this out, I have never tried tuning a car like my own can you friend me on face book? Steven Main I have lots of questions
Like for example my car has no 02 sensors as I built it, and is obviously speed density so wouldn't it be pulling from the open loop fuel modifier table 100% of the time?
Like for example my car has no 02 sensors as I built it, and is obviously speed density so wouldn't it be pulling from the open loop fuel modifier table 100% of the time?
05-29-2012 | 10:13 PM
#27
No problem. Couldn't find you on FB.
PM sent.
Also for the cubes of your motor and the size of the turbo your cam could stand to be a bit bigger.
Try to work with the tune-up first though, see if we can't get you straightened out.
PM sent.
Also for the cubes of your motor and the size of the turbo your cam could stand to be a bit bigger.
Try to work with the tune-up first though, see if we can't get you straightened out.
