FWD-TT Is it possible to...

[Kibwe Walker]

Originally Posted by cbehnken

how's $300 on a good DR650

I still would be worried about pushing them hard because dr650's are clipped turbines.

The majority of the backpressure in our cars has nothing to do with the exhaust, it has everything to do with the turbine and turbine housing. So just play with that scenario in your mind engine bank 1,3,5 is seeing different amounts of backpressure compared to 2,4,6 on the exhaust stroke. At low boost settings, its no big deal but at the settings where the dr650 is doing most of the work and the other turbo is out of its efficency range thats unequal amounts of stress on your crank coming from the different banks.

A engine is harmonic chaos, you don't want to do anything that will break up the harmony and unequal pressures is one thing you can do to destroy the harmony. Not that your engine will fail immediately because it won't, our engines are pretty strong but I wouldn't roll around at 18-20 psi for a whole tank either.

[Hannibalzero]

Originally Posted by cbehnken

how's $300 on a good DR650

Well, that would qualify as an unbeatable deal.

[cbehnken]

Originally Posted by Kibwe Walker

I still would be worried about pushing them hard because dr650's are clipped turbines.

The majority of the backpressure in our cars has nothing to do with the exhaust, it has everything to do with the turbine and turbine housing. So just play with that scenario in your mind engine bank 1,3,5 is seeing different amounts of backpressure compared to 2,4,6 on the exhaust stroke. At low boost settings, its no big deal but at the settings where the dr650 is doing most of the work and the other turbo is out of its efficency range thats unequal amounts of stress on your crank coming from the different banks.

A engine is harmonic chaos, you don't want to do anything that will break up the harmony and unequal pressures is one thing you can do to destroy the harmony. Not that your engine will fail immediately because it won't, our engines are pretty strong but I wouldn't roll around at 18-20 psi for a whole tank either.

I wish you'd get over it. Your theory sounds great, but not a single person has ever hurt their motor from different turbos. A few have even run 9bs with 15G/DR650 size turbos for some time.

I am going to have to be WAY over 20 PSI to have the DR650 doing most of the work. I easily held 17 to redline before. Maybe if I tried going all out and ran 25 PSI it'd be a problem.

I am totally injector limited and this car will probably NEVER see over 18 PSI or so even when i go to bigger injectors. This is not a race gas car.

If there was a problem it would be easy to feel this out of balance condition your theory suggests at high RPM/ high boost and believe me it is as smooth as ever.

So, whenever a post like this comes up inevitably you are going to post how the theory says boom and I am going to post how in practice there are no problems.



Edit: Oh and the reason for no race gas is I don't see the point of producing track results I can't produce on the street because I drive this car every day. It is my ONLY car.

Edit2: I am sure you have seen the stock downpipe. How's that for equal flow!

[Kibwe Walker]

Originally Posted by cbehnken

I wish you'd get over it. Your theory sounds great, but not a single person has ever hurt their motor from different turbos. A few have even run 9bs with 15G/DR650 size turbos for some time.

I am going to have to be WAY over 20 PSI to have the DR650 doing most of the work. I easily held 17 to redline before. Maybe if I tried going all out and ran 25 PSI it'd be a problem.

I am totally injector limited and this car will probably NEVER see over 18 PSI or so even when i go to bigger injectors. This is not a race gas car.

If there was a problem it would be easy to feel this out of balance condition your theory suggests at high RPM/ high boost and believe me it is as smooth as ever.

So, whenever a post like this comes up inevitably you are going to post how the theory says boom and I am going to post how in practice there are no problems.



Edit: Oh and the reason for no race gas is I don't see the point of producing track results I can't produce on the street because I drive this car every day. It is my ONLY car.

Edit2: I am sure you have seen the stock downpipe. How's that for equal flow!

Thats basically what I am saying.

You can run like this as long as you don't push the setup where 1 turbo is doing all the work and the other is way out of its efficiency range.

For that matter thats exactly what I said. The wierd thing is I don't have to break things to figure out how they will break. Riding around on low boost won't ever do anything to our bottom end but for what you risk and what you gain is it really worth it?

Example being a 9b/13g setup. Phalse already ran 11.7 with that years ago. Don't know if it was a true L turbine 13g' or a 9b converted to 13g (same turbines). You can do that big deal. I am not going to recommend something to any 3s owner when their is no real benefit to doing so.

For you both your turbos are within their efficiency range so big nothing. You can roll like that forever. Now if you get fuel and meth or whatever to where you can be outside the 13g's efficiency range consistantly everytime you go WOT then you fall into the POTENTIAL damage area with unequal balance between the banks. It won't fail immediately, it won't fail in 10 miles or even a 100 but it will fail sooner than if you had your engine balanced with equal turbos/backpressure.

When that is, who knows, I have no desire to find out, and like I said our motors are pretty stout, but they are metal, they don't get stronger with use and or abuse. I just want mine around as long as possible and hope you and other 3s owners get the same.

[cbehnken]

Originally Posted by Kibwe Walker

Thats basically what I am saying.

You can run like this as long as you don't push the setup where 1 turbo is doing all the work and the other is way out of its efficiency range.

For that matter thats exactly what I said. The wierd thing is I don't have to break things to figure out how they will break. Riding around on low boost won't ever do anything to our bottom end but for what you risk and what you gain is it really worth it?

Example being a 9b/13g setup. Phalse already ran 11.7 with that years ago. Don't know if it was a true L turbine 13g' or a 9b converted to 13g (same turbines). You can do that big deal. I am not going to recommend something to any 3s owner when their is no real benefit to doing so.

For you both your turbos are within their efficiency range so big nothing. You can roll like that forever. Now if you get fuel and meth or whatever to where you can be outside the 13g's efficiency range consistantly everytime you go WOT then you fall into the POTENTIAL damage area with unequal balance between the banks. It won't fail immediately, it won't fail in 10 miles or even a 100 but it will fail sooner than if you had your engine balanced with equal turbos/backpressure.

When that is, who knows, I have no desire to find out, and like I said our motors are pretty stout, but they are metal, they don't get stronger with use and or abuse. I just want mine around as long as possible and hope you and other 3s owners get the same.

There is a benefit though. Whenever someone is selling a single turbo cheap you can pick one up and always pick up another later.

DR650s do not spool like 13Ts. If I had two DR650s I know it would be laggier than my 13Gs. I now have a combo of the lag with more top end.

I also have probably $400-450 in both turbos combined. I really don't know how you can beat that for a combination that should hold 20 PSI (or close) to redline.

This engine has 142K on it, but still runs perfect. If it failed tomorrow I could hardly be mad at it.

Stock rings and pistons yet, good compression yet and perfect oil pressure now. This engine also ran a 9b/13G for a LONG time.

Feral (I think that was his username) ran a 9b and a DR650 combo for a while without issue.

I can't drive that great, so I need all the help I can get. I want this car to go down the track from power and not from driver. 13Gs aren't going to do that for me, so here we are...

Edit: wait, I sold my stock turbine housing for $50 and if my rear turbo sells for $150 like I hope I will have about 200-250 in this whole setup

[Kibwe Walker]

can't beat that price but even then you still aren't where I am talking about.

13g's are done at 18/19 psi holding 17 to redline. I wouldn't be worried unless I was pushing 24 psi or something like that where the 13g is beyond done and the dr650 is doing all the work.

[Jason61991]

Well basically I was afraid of spool time but 13Gs and 19Ts spool quick enough, especially compared to DR650s.

So never mind the mismatching turbos.

[cbehnken]

Originally Posted by Jason61991

Well basically I was afraid of spool time but 13Gs and 19Ts spool quick enough, especially compared to DR650s.

So never mind the mismatching turbos.

Well 13Gs pretty much spool off idle if you have gutted or no cats. I'm not sure any upgraded turbo can spool faster.

Are you running NA gears? you are going to have so many traction problems I don't think lag is ever going to be a problem for you.

[Jason61991]

Originally Posted by cbehnken

Well 13Gs pretty much spool off idle if you have gutted or no cats. I'm not sure any upgraded turbo can spool faster.

Are you running NA gears? you are going to have so many traction problems I don't think lag is ever going to be a problem for you.

Yeah, I have N/A gears.
Going to start buying mods and then hit TT when ready.
But this topic crossed my mind so I had to ask.

What would be a good way to offset those traction problems?

[cbehnken]

Originally Posted by Jason61991

Yeah, I have N/A gears.
Going to start buying mods and then hit TT when ready.
But this topic crossed my mind so I had to ask.

What would be a good way to offset those traction problems?

solid motor mounts and good tires to start.