Low Power with Large Turbo

[turbovanman²]

A lower stall converter is actually better as it acts like a clutch, its on off idle and makes for a fun car to drive. I prefer lower stall converters BUT if you want to spool the turbo at the track, FORGET it. Hughes will make a converter based on what you tell them, they did one for me, was awesome but slipped a bit too much on the highway, LU fixed that.
A proper stage III 50 trim won't hit full boost until around 4200 rpm on an 8 valve with a stock or Taft S2, ported head.

My van was fun at 18 psi with a 8 valve engine, stage III 50 trim so you have some tuning issues. Its a laggy combo but when in song, its fun.

[mr b]

A lower stall converter is actually better as it acts like a clutch, its on off idle and makes for a fun car to drive. I prefer lower stall converters BUT if you want to spool the turbo at the track, FORGET it. Hughes will make a converter based on what you tell them, they did one for me, was awesome but slipped a bit too much on the highway, LU fixed that.
A proper stage III 50 trim won't hit full boost until around 4200 rpm on an 8 valve with a stock or Taft S2, ported head.

My van was fun at 18 psi with a 8 valve engine, stage III 50 trim so you have some tuning issues. Its a laggy combo but when in song, its fun.

Thanks man I hope to have some logging done within a week or 2. So many projects so little time.

[turbovanman²]

Thanks man I hope to have some logging done within a week or 2. So many projects so little time.

I hear you man, there simply isn't enough hours left in the day,

[A.J.]

I got my tweaked converter back from Hughes. It's a lot better. I'm not sure what the true stall is but it breaks the tires loose from a brake stand at 3500 (instead of the previous 4000) and when accelerating from a stop light it only revs to 3500 (instead of the previous 4000). I don't know how this converter will perform in an 8 valve engine since all converters will perform differently in different vehicles but they have my converter build on file incase anyone wants to attempt a converter like mine.

[5DIGITS]

I got my tweaked converter back from Hughes. It's a lot better. I'm not sure what the true stall is but it breaks the tires loose from a brake stand at 3500 (instead of the previous 4000) and when accelerating from a stop light it only revs to 3500 (instead of the previous 4000). I don't know how this converter will perform in an 8 valve engine since all converters will perform differently in different vehicles but they have my converter build on file incase anyone wants to attempt a converter like mine.

This is a great thread !
It is difficult to isolate one root cause when so many variables are at work here.
Remember, stall is a function of engine torque and what you say is true - they will all act differently based on the engine, torque, vehicle weight, etc....
On the other hand, if a turbo cannot reach the boost goal at the scheduled target gear upshift point, the turbo will stall upon an upshift.
For example, if the turbo obtains its boost target at 4400RPM and the 2nd gear RPM is 4000RPM, after the 1-2 upshift, the turbo will decelerate, stall, and a performance 'sag' will be realized.
This is independent of where the TC stall is located and the need for a higher shift point (or turbo correction) is more critical, to reduce performance losses.
In this case, a modified 'tongue' and WG hole .48 housing can correct the sag, improve street response, and will breath near the level of a .63 housing but will not exceed it.
Finally, the spark advance curves on an automatic are very different than a manual calibration, if things are done properly.
This is largely due to the inability to lug the engine, as you can with a manual, at lower RPM's.
Reduced time at load permits a more aggressive spark curve on an automatic, especially below and up to the stall/coupling point.
This in itself is a significant contributor to the over-all drive-ability of the vehicle.

Thanks for posting and keep us updated.

[wallace]

I got my tweaked converter back from Hughes. It's a lot better. I'm not sure what the true stall is but it breaks the tires loose from a brake stand at 3500 (instead of the previous 4000) and when accelerating from a stop light it only revs to 3500 (instead of the previous 4000). I don't know how this converter will perform in an 8 valve engine since all converters will perform differently in different vehicles but they have my converter build on file incase anyone wants to attempt a converter like mine.

What has been done to the converter and do you know if its a stock core that was modified? Was the re-stall free? I just sent mine out and got it back..I used the stock turbo converter that came in the car. He did what he could with it as he said there aren't any aftermarker stators or sprag/diodes for it. I had it rollerized, the stock stator was brazed, and I had him loosen it 4-500 rpm.

[A.J.]

What has been done to the converter and do you know if its a stock core that was modified? Was the re-stall free? I just sent mine out and got it back..I used the stock turbo converter that came in the car. He did what he could with it as he said there aren't any aftermarker stators or sprag/diodes for it. I had it rollerized, the stock stator was brazed, and I had him loosen it 4-500 rpm.

I don't know what was done. They supplied the converter. The re-stall was free. I guess after they built the converter and I gave them feedback on how it performed they knew what needed to be done. I had given them my known 2800 stall converter if they wanted to cut it open to see what a 2800 looked like in my van but they didn't need to.

[R/T]

but they have my converter build on file incase anyone wants to attempt a converter like mine.

What did it cost??

[A.J.]

What did it cost??

$540ish.

[jonnyb]

Not to be negative or stray from the intent of this thread, but I have to say you got lucky AJ (or benefited from the R&D they did on my converter) and I would make the same recommendation to the original poster - find a local TC builder.

After paying freight and shipping my converter back to Hughes twice ($75 each way=$300 in shipping), it's still not even close. I asked for 2800 RPM (heavily ported head, s60 turbo with .63 on a 2.5 in my van) and the first one they sent slipped to 4K. Sent it back and got 3600. Sent it back again and got 3K when I brake boost (alright - good enough I thought), but then I noticed that in 2nd and 3rd, the increased load will push it to slip up to 4K. 1/2 shift and 2/3 shift feel soft because the TC blows right through the 3K limit and the converter just slips until my speed gets up past 4K rpm. After a couple hundred miles of driving, I couldn't stand it anymore (with lockup on highway it's not bad, but around town is sucks!) and the poor van has been sitting for months because I don't feel like pulling the trans again, and even if I did, I don't really want to pay another $150 for round trip shipping to have Hugh's "guess" at it again. So I've got a mint van with an $800 paper weight of a converter in it.

AJ - when we spoke, I don't remember if you told me where you got that 2800 rpm stall converter you had on your van before. Would you mind posting that up? I'm probably making around 250 whp/300 tq in the van - do you think the one you were using would hold up to that?

I'm so frustrated and just want to drive the van that I was thinking about turning boost down to lower the power output, and just picking up the $99 PT Cruiser replacement unit from AutoZone.

[mr b]

Not to be negative or stray from the intent of this thread, but I have to say you got lucky AJ (or benefited from the R&D they did on my converter) and I would make the same recommendation to the original poster - find a local TC builder.

After paying freight and shipping my converter back to Hughes twice ($75 each way=$300 in shipping), it's still not even close. I asked for 2800 RPM (heavily ported head, s60 turbo with .63 on a 2.5 in my van) and the first one they sent slipped to 4K. Sent it back and got 3600. Sent it back again and got 3K when I brake boost (alright - good enough I thought), but then I noticed that in 2nd and 3rd, the increased load will push it to slip up to 4K. 1/2 shift and 2/3 shift feel soft because the TC blows right through the 3K limit and the converter just slips until my speed gets up past 4K rpm. After a couple hundred miles of driving, I couldn't stand it anymore (with lockup on highway it's not bad, but around town is sucks!) and the poor van has been sitting for months because I don't feel like pulling the trans again, and even if I did, I don't really want to pay another $150 for round trip shipping to have Hugh's "guess" at it again. So I've got a mint van with an $800 paper weight of a converter in it.

AJ - when we spoke, I don't remember if you told me where you got that 2800 rpm stall converter you had on your van before. Would you mind posting that up? I'm probably making around 250 whp/300 tq in the van - do you think the one you were using would hold up to that?

I'm so frustrated and just want to drive the van that I was thinking about turning boost down to lower the power output, and just picking up the $99 PT Cruiser replacement unit from AutoZone.

That's not good at all. I didn't consider the shipping aspect if it has to be redone. At some point they should cover it for not doing it correctly.

[jonnyb]

Agreed and that's what I said too, but they told me that they were spending time and money on redoing it every time and thought it was only fair that I pay shipping. They didn't seem to look at it from the consumers point of view, which was in my mind, that I had bought a faulty product that was not what they advertised. The guys I spoke with and worked with were nice enough and seemed to want to get it right, but unfortunately, they just did not seem to be able to do that.

[A.J.]

Not to be negative or stray from the intent of this thread, but I have to say you got lucky AJ (or benefited from the R&D they did on my converter) and I would make the same recommendation to the original poster - find a local TC builder.

After paying freight and shipping my converter back to Hughes twice ($75 each way=$300 in shipping), it's still not even close. I asked for 2800 RPM (heavily ported head, s60 turbo with .63 on a 2.5 in my van) and the first one they sent slipped to 4K. Sent it back and got 3600. Sent it back again and got 3K when I brake boost (alright - good enough I thought), but then I noticed that in 2nd and 3rd, the increased load will push it to slip up to 4K. 1/2 shift and 2/3 shift feel soft because the TC blows right through the 3K limit and the converter just slips until my speed gets up past 4K rpm. After a couple hundred miles of driving, I couldn't stand it anymore (with lockup on highway it's not bad, but around town is sucks!) and the poor van has been sitting for months because I don't feel like pulling the trans again, and even if I did, I don't really want to pay another $150 for round trip shipping to have Hugh's "guess" at it again. So I've got a mint van with an $800 paper weight of a converter in it.

AJ - when we spoke, I don't remember if you told me where you got that 2800 rpm stall converter you had on your van before. Would you mind posting that up? I'm probably making around 250 whp/300 tq in the van - do you think the one you were using would hold up to that?

I'm so frustrated and just want to drive the van that I was thinking about turning boost down to lower the power output, and just picking up the $99 PT Cruiser replacement unit from AutoZone.

I did get lucky after hearing about your trouble. When I tried it the first time and it revved to 4000 I thought, "Oh great, here we go" but after I got it back it was great. The more and more I drive it the bigger the smile gets on my face. I wish you could enjoy your van as much as I enjoy mine.

I bought my 2800 stall converter from a company in California in December of 2010 called "Trans Parts Inc." Their phone numbers are 559-237-4463/800-281-4463. Their address is 344 M Street Fresno, CA 93721. On my bill the converter is listed as item number: 975A. The parts description is: 91+ 2.0/2.2/2.4/2.5L & all turbos converter.

That's not good at all. I didn't consider the shipping aspect if it has to be redone. At some point they should cover it for not doing it correctly.

That's why I recommended finding a local builder.

[Reaper1]

I don't know if they are still around, but I bought a NAN TC many years ago for my van. It wasn't nearly as powerful as your guy's, but it was dead nuts perfect. It actually had a tighter stall than stock (if the engine was stock), but with the higher boost/torque it was great. I think it was right around 3200-3500rpm.

[mr b]

Agreed and that's what I said too, but they told me that they were spending time and money on redoing it every time and thought it was only fair that I pay shipping. They didn't seem to look at it from the consumers point of view, which was in my mind, that I had bought a faulty product that was not what they advertised. The guys I spoke with and worked with were nice enough and seemed to want to get it right, but unfortunately, they just did not seem to be able to do that.

At some point, you have to call it a day and use a different company. It's not right for them to keep messing it up and then repeatedly charge the customer for shipping to and from. At the very least they should cover shipping to you. Not to be a jerk but you can return it and make a claim with your credit card. Fortunately most of the vendors we have here are standup.

[A.J.]

I don't know if they are still around, but I bought a NAN TC many years ago for my van. It wasn't nearly as powerful as your guy's, but it was dead nuts perfect. It actually had a tighter stall than stock (if the engine was stock), but with the higher boost/torque it was great. I think it was right around 3200-3500rpm.

Stock for a turbo car is 3000-3300 and for a turbo mini-van it's 3300-3500.

At some point, you have to call it a day and use a different company. It's not right for them to keep messing it up and then repeatedly charge the customer for shipping to and from. At the very least they should cover shipping to you. Not to be a jerk but you can return it and make a claim with your credit card. Fortunately most of the vendors we have here are standup.

I could see two to three times for a car that's not that common, once for a more common vehicle. Once too loose, twice too tight, third time dead on. When I contacted Hughes after my initial install I tried to gather as much information as possible so they knew when they opened up the one they built for me what they were looking at was performing ___________ on my van. I even gave them my 2800 stall converter for them to cut open so they could see what too low a stall looked like in my van. They didn't have to cut it open and they got it right the second time. It only takes me 50 minutes to pull my trans but it doesn't mean I want to do it over and over. But for something as one-off as my van, I was prepared to do it a couple of times.

[jonnyb]

At some point, you have to call it a day and use a different company. It's not right for them to keep messing it up and then repeatedly charge the customer for shipping to and from. At the very least they should cover shipping to you. Not to be a jerk but you can return it and make a claim with your credit card. Fortunately most of the vendors we have here are standup.

I'm pretty sure they did offer a refund if I shipped it back (and paid for shipping it back of course). I was thinking about doing that, but just didn't have the time/energy to pull the transmission again. I guess I'm not as good as AJ, because it takes me way more than 50 minutes...LOL!

Like I said, with the exception of the fact that they kept making me pay for shipping, they were good guys to work with and really seemed like they wanted to make their product work for me.

I'm going to upgrade the Holset HE341 (HY35) in my 03 Ram Cummins soon with an HE351. I've been thinking maybe I'll just throw the HE341 in the van. I'm sure I'll need the extra stall to spool that, and since it will be much more efficient in the upper rpm range than the s60 (due to the big port head) maybe I'll have a wide enough power band to make that stall work. Right now though, the power starts to fall off hard after 5K rpm, so that only gives me a 1000rpm where I can actually use the power I'm making and that just plain sucks!

I want that minivan smile back!

EDIT: forgot to say, I did contact NAN and they told me they don't make lockup TC's for our transmissions. Also, wanted to say thanks for the info AJ - I'll try giving them a call.

[jonnyb]

Also, I've got a buddy that is in the process of doing a PT Cruiser 2.4/auto conversion in his rampage, and he's got a big turbo going on, so I may just trade converters with him (and hopefully have him give me some cash). He said the before he pulled the drivetrain from the PT, the TC seemed OK and stalled around 2800 when he brake boosted it. So it really sounds like that's what I want if I stick with my current setup (guessing PT is about same weight as my van and has slightly less power, but not much if I keep the boost set at a reasonable level so it should stall about the same in my van).

[A.J.]

So I made a little discovery today that I suggest everyone check. I bought 120 lb/hr injectors and tried to do some street tuning before taking it for dyno tuning on Thursday. We tune for 15 psi and it does okay, AFR's in the 11's. Tried to tune it for 25 psi and couldn't get it to the 11's. 80% duty cycle and can't get it out of the 12's. Been doing some research to see if I'm going to need a bigger fuel pump to run E85 and found this:http://www.srtforums.com/forums/f187...r-pump-670033/ and then this:http://www.srtforums.com/forums/f187...h-fuel-320074/. So I'm thinking I'm already running out of fuel and I'm still running 91 octane. I put a fuel pressure gauge on and removed the hood and go for a drive. My fuel pressure is set to 43 psi with the vacuum line off, it's in the 30's with it on. Go for a drive. At 15 psi of boost I should have 58 psi of fuel pressure. I had 51 psi. At 25 psi of boost I have 40 psi of fuel pressure. I'm going the wrong effing way. I get back to the shop and put my cylinder leak down tester on the fuel pressure regulator and with the van running with 20 psi of regulated air on the fuel pressure regulator it rose to 63 psi. So I think I might have a bad pump. I just bought a Deatschwerks 200 (255 lph comparable to the Walbro 255) back in July/August. I realize because it's newish doesn't mean it can't be bad. I have some other things to get done before I can drop the tank to make sure I don't have an internal leak. If I don't I'm going to borrow a Deaschtwerks 300 (340 lph) to diag the low fuel pressure problem. My van seemed a little sluggish. Like it doesn't have the get up and go like a 16 valve minivan ought to have. It got a little better with the right torque converter but here is a HUGE problem that needs to be fix and was easily overlooked.

[wallace]

So I made a little discovery today that I suggest everyone check. I bought 120 lb/hr injectors and tried to do some street tuning before taking it for dyno tuning on Thursday. We tune for 15 psi and it does okay, AFR's in the 11's. Tried to tune it for 25 psi and couldn't get it to the 11's. 80% duty cycle and can't get it out of the 12's. Been doing some research to see if I'm going to need a bigger fuel pump to run E85 and found this:http://www.srtforums.com/forums/f187...r-pump-670033/ and then this:http://www.srtforums.com/forums/f187...h-fuel-320074/. So I'm thinking I'm already running out of fuel and I'm still running 91 octane. I put a fuel pressure gauge on and removed the hood and go for a drive. My fuel pressure is set to 43 psi with the vacuum line off, it's in the 30's with it on. Go for a drive. At 15 psi of boost I should have 58 psi of fuel pressure. I had 51 psi. At 25 psi of boost I have 40 psi of fuel pressure. I'm going the wrong effing way. I get back to the shop and put my cylinder leak down tester on the fuel pressure regulator and with the van running with 20 psi of regulated air on the fuel pressure regulator it rose to 63 psi. So I think I might have a bad pump. I just bought a Deatschwerks 200 (255 lph comparable to the Walbro 255) back in July/August. I realize because it's newish doesn't mean it can't be bad. I have some other things to get done before I can drop the tank to make sure I don't have an internal leak. If I don't I'm going to borrow a Deaschtwerks 300 (340 lph) to diag the low fuel pressure problem. My van seemed a little sluggish. Like it doesn't have the get up and go like a 16 valve minivan ought to have. It got a little better with the right torque converter but here is a HUGE problem that needs to be fix and was easily overlooked.

Did you run a dedicated set of wires back to the pump? Is this a return style fuel system? I will be interested to know how far the 120's will get you when you make the switch to e85. Great info thanks for sharing.