Turbo won’t spool up after going from 80mm to 106 precision
03-27-2019, 08:35 PM
#1
Staging Lane
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Turbo won’t spool up after going from 80mm to 106 precision Okay I know a ton of you guys are gunna say “told you so “ that were on my other thread. But as title says I went from a bw s480 cast wheel to a big daddy precision 106mm billet wheel I got it used but brand new for a good deal but it had the 1.50 hotside on it which I thought was gunna be too big. The compressor wheel literally doesn’t spin at all while it’s idling. But now I put it on the trans brake and it just sits around 3000 rpms not even high enough to go on the 2 step with the pedal to the floor then it started slipping. Just want to get other people’s opinion do you think I should send the converter back to circle d to work whatever magic they do and then Try it with the 1.50 hot side? Or just switch to a smaller hotside and try it? Or do both? Just looking for opinions not bashing I knew I was going to have to change some things going to the big leagues. Thanks !
03-27-2019, 09:04 PM
#2
Remind us:
motor ci
comp ratio
fuel
cam specs
50 - 100 shot likely get it going.
motor ci
comp ratio
fuel
cam specs
50 - 100 shot likely get it going.
03-27-2019, 09:13 PM
#3
Staging Lane
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**** sorry it’s a 427dart ls next 10:1 compression, blow thru carb on c16, I don’t have the cam specs with me but it’s a custom turbo grind, motor was built by late model engines. With the cast 80 the thing would light up instantly and make up to 15lbs on the brake. I know nitrous would get it going but I want to avoid that if I can.
03-27-2019, 09:36 PM
#4
I am not going to be any help to you but am just curious. If you were to take it to the track the way it is, would you be traction limited in first? In other words, would you have to pull timing/boost to get your best 60 foot times?
03-27-2019, 09:42 PM
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yea traction is my issue , or wheelies. Even with the small turbo I was only leaving on 5lbs of boost and ramping in to 25lbs and 20* of toning around 1 sec into the run. The steep gear in the turbo 400 makes 1st gear pretty useless. Might be switching to a glide
03-28-2019, 08:59 AM
#7
Okay I know a ton of you guys are gunna say “told you so “ that were on my other thread. But as title says I went from a bw s480 cast wheel to a big daddy precision 106mm billet wheel I got it used but brand new for a good deal but it had the 1.50 hotside on it which I thought was gunna be too big. The compressor wheel literally doesn’t spin at all while it’s idling. But now I put it on the trans brake and it just sits around 3000 rpms not even high enough to go on the 2 step with the pedal to the floor then it started slipping. Just want to get other people’s opinion do you think I should send the converter back to circle d to work whatever magic they do and then Try it with the 1.50 hot side? Or just switch to a smaller hotside and try it? Or do both? Just looking for opinions not bashing I knew I was going to have to change some things going to the big leagues. Thanks !
**** sorry it’s a 427dart ls next 10:1 compression, blow thru carb on c16, I don’t have the cam specs with me but it’s a custom turbo grind, motor was built by late model engines. With the cast 80 the thing would light up instantly and make up to 15lbs on the brake. I know nitrous would get it going but I want to avoid that if I can.
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03-28-2019, 09:08 AM
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spins fine by hand touch the throttle at all it starts to spin, those are both mid frame turbos this thing is huge compared to a pro mod 94. It’s got a 5 inch bumper exit exhaust and a 1.50 hotside. I think it’s just flowing way to much exhaust.
03-28-2019, 09:26 AM
#9
Are you really trying to make 2000whp? But really a 408 can spin up the 106mm so I think your problem is elsewhere and a 427 can easily spin up twin 76's or 80's with more combined wheel without issue so really shouldn't be an issue, not like a single 5" exhaust is that big. What's your A/F and timing on spoolup? Why don't you lower your two step setup to build boost at same RPM it goes on the brake?
03-28-2019, 09:43 AM
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Yea really trying to go 4.70’s in the eighth. It went 5.40 with the cast wheel 80mm on it. The timing is 29* I’m going to change a couple things tonight add some more timing and more fuel on the trans brake that’s what everyone has been telling me, and lower the rpm on the 2 step and see what it does. I will report back lol
03-28-2019, 09:52 AM
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03-28-2019, 10:43 AM
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03-28-2019, 02:37 PM
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i follow John doc, the turbo he has on there is a garret 88mm gt55 but he just got a smaller one from Jose at forced induction. My compressor wheel is 106mm his is 88 a lot more to get spinning. I’m heading to shop now gunna do some tuning changes and see what I can make happen. I will check for leaks as well but I’m pretty sure there isn’t any on the hotside
03-28-2019, 04:05 PM
#19
I asked about the hotide for the layout not leaks
I figured it was headers, are the up pipes 2.5" like they look?
Being that you don't even have rotation at idle you will have your hands full. Id be going to a 1.3 or a 1.0 on that G trim to start with
From what you said, your NA stall speed on the converter is around 3k, even if everything was right I doubt that will be enough to get a G trim thumper started rolling without something like nitrous
I'd start by swapping housings minimum
You really would be much better off with a gt55 based unit, I know you don't want to hear it
Converter and everything would be fine as is
On my 94mm gt55 with a 1.24 I can get it lit off with the converter stall point similar no problem, it also hauls *** at idle, you can't hold the nut on the compressor and keep from spinning when you start it, alot of tq there
I figured it was headers, are the up pipes 2.5" like they look?
Being that you don't even have rotation at idle you will have your hands full. Id be going to a 1.3 or a 1.0 on that G trim to start with
From what you said, your NA stall speed on the converter is around 3k, even if everything was right I doubt that will be enough to get a G trim thumper started rolling without something like nitrous
I'd start by swapping housings minimum
You really would be much better off with a gt55 based unit, I know you don't want to hear it
Converter and everything would be fine as is
On my 94mm gt55 with a 1.24 I can get it lit off with the converter stall point similar no problem, it also hauls *** at idle, you can't hold the nut on the compressor and keep from spinning when you start it, alot of tq there
03-28-2019, 04:35 PM
#20
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I asked about the hotide for the layout not leaks
I figured it was headers, are the up pipes 2.5" like they look?
Being that you don't even have rotation at idle you will have your hands full. Id be going to a 1.3 or a 1.0 on that G trim to start with
thanks for the info man a lot of good suggestions. As for the hotside yes it’s 2.5” and stainless works headers. Yea this big *** g trim wheel I think I’m going to have to go to a 1.0 housing.
But it I figured out something just now when I press the trans brake button it is supposed to turn on the 2 step but it is not doing that so that is why the car isn’t sitting on it and popping and banging.
From what you said, your NA stall speed on the converter is around 3k, even if everything was right I doubt that will be enough to get a G trim thumper started rolling without something like nitrous
I'd start by swapping housings minimum
You really would be much better off with a gt55 based unit, I know you don't want to hear it
Converter and everything would be fine as is
On my 94mm gt55 with a 1.24 I can get it lit off with the converter stall point similar no problem, it also hauls *** at idle, you can't hold the nut on the compressor and keep from spinning when you start it, alot of tq there
I figured it was headers, are the up pipes 2.5" like they look?
Being that you don't even have rotation at idle you will have your hands full. Id be going to a 1.3 or a 1.0 on that G trim to start with
thanks for the info man a lot of good suggestions. As for the hotside yes it’s 2.5” and stainless works headers. Yea this big *** g trim wheel I think I’m going to have to go to a 1.0 housing.
But it I figured out something just now when I press the trans brake button it is supposed to turn on the 2 step but it is not doing that so that is why the car isn’t sitting on it and popping and banging.
From what you said, your NA stall speed on the converter is around 3k, even if everything was right I doubt that will be enough to get a G trim thumper started rolling without something like nitrous
I'd start by swapping housings minimum
You really would be much better off with a gt55 based unit, I know you don't want to hear it
Converter and everything would be fine as is
On my 94mm gt55 with a 1.24 I can get it lit off with the converter stall point similar no problem, it also hauls *** at idle, you can't hold the nut on the compressor and keep from spinning when you start it, alot of tq there
I figured it was headers, are the up pipes 2.5" like they look?
Being that you don't even have rotation at idle you will have your hands full. Id be going to a 1.3 or a 1.0 on that G trim to start with
thanks for the info man a lot of good suggestions. As for the hotside yes it’s 2.5” and stainless works headers. Yea this big *** g trim wheel I think I’m going to have to go to a 1.0 housing to get it really cooking. I was going to buy a gt55 98 from Jose at forces inductions but got a sick deal on this 106 used for mock up that I couldn’t pass up the only downside was it had this huge 1.50 exhaust housing which isn’t a big deal to swap.
But it I figured out something just now that’s def causing boosting issues!! when I press the trans brake button it is supposed to turn on the 2 step as well but it is not doing that. so that is why the car isn’t sitting on it and isn’t popping and banging to get the turbo moving. So it’s either a wiring problem or the msd box.