"REPEAT OFFENDER" - Swoles back at it!

[Jim Fulmer]

My last 4 runs down the track only cost a little over $1000 each so I just need to pick up a side job. Maybe brain surgery or politician.(polar opposites).

That's the reason I stayed on the dyno.....no racing budget!

Jim

 

[Big Swole]

I had the same issue on my 95, went from 57psi to 66psi, and the boost on the atmosphere dropped a lot. It was only part of the story though, as drive pressure went from 72 to 99! I actually didn't pick up any power. So, leaving it wastegated might actually be a good thing.

I was wondering about this and may have proven it the other night.
I didn't gain anything at the track by having it clamped off completely.

I really want to test it at a 1/4 mile track though. So far I've only made it down the 1/8.

Funny thing is, on the street it feels a little more powerfully with it clamped.
My seat Of pants meter must need to be calibrated.. lol

My last 4 runs down the track only cost a little over $1000 each so I just need to pick up a side job. Maybe brain surgery or politician.(polar opposites).

LOL

thats some expensive passes Ron.

 

[dvst8r]

So I am assuming this means you got the plugs in to replace those pop off valves? Did you notice any difference in your boost or egt's? Or were yours one of the few sets that actually sealed?

 

[Big Swole]

So I am assuming this means you got the plugs in to replace those pop off valves? Did you notice any difference in your boost or egt's? Or were yours one of the few sets that actually sealed?

Yes Sir!! The valves are out and plugs are IN!!

Seems like the egt's are a bit lower.

They Must have been sealing because I had the tube clamped off before removal and it was making 72-75 psi.. Once they were pluged, same exact boost numbers.

Now I just need to order one of those In-Cab boost controllers so I can get the turbos tuned to 50/50... Or do more testing once I get to a 1/4 track.

I would think going from 63 ish to 75 ish psi would have made a difference.
But WithOUT a tc lock up switch and it's not locking until the 1/8 is almost over, maybe it can't get to full tilt to show the difference yet.

I think I'll at least do a with and with out the clamp test at a 1/4 mile track before changing anything else.. See if it actually makes it faster.

 

[Joesixpack]

I had the same issue on my 95, went from 57psi to 66psi, and the boost on the atmosphere dropped a lot. It was only part of the story though, as drive pressure went from 72 to 99! I actually didn't pick up any power. So, leaving it wastegated might actually be a good thing.

I was wondering about this and may have proven it the other night.
I didn't gain anything at the track by having it clamped off completely.

I really want to test it at a 1/4 mile track though. So far I've only made it down the 1/8.

Funny thing is, on the street it feels a little more powerfully with it clamped.
My seat Of pants meter must need to be calibrated.. lol







LOL

thats some expensive passes Ron.

Here's a graph showing what you guys are seeing. It's the two extremes gate locked down and gate locked open.

This was with the ~700 hp max on stock nozzles so the difference would be considerably more with some heavy fuel.

Forgive the spikes the optical rpm sensor was flaking out.

Had I started the run lower the bottom end would be much more pronounced (Gate closed)

Perfect gate response takes some work in my case with the dual internals locked down hard in the bottom end and by about 2800 RPM's full open.

(Now a external gate with more flow could dump too much at full open if it was large enough)

It will feel more powerful on the street clamped down as you are generally working off the bottom end, but peak power in the upper rpm's will undoubtedly suffer.

 

[Big Swole]

Thanks Chris for that info!!

I guess I'll unclamp it for now (making 62-63 ish total & primary closer to 38-40)
And trust that it's better for the motor power and drive pressure wise.

But one last question.
If I still get the "Turbosmart" in-cab boost controller, will getting it closer to a 50/50 split still technically be the best setup for over all power / drive??

Hoping to see maybe 65 ish total and the Primary making exactly half of that??



Thanks again for the help guys..

 

[JQmile]

It will feel more powerful on the street clamped down as you are generally working off the bottom end, but peak power in the upper rpm's will undoubtedly suffer.

I don't have the graphs handy, but drive pressure stayed in check for a little while, until about 2500rpm. After that, it made a hard upwards turn and then plateaued again from about 2700rpm to 3100rpm at 95-99psi.

Funny thing was, it never felt faster to me, it actually felt slower up top, and the dyno seemed to back up that feeling.

 

[JQmile]

Thanks Chris for that info!!

I guess I'll unclamp it for now (making 62-63 ish total & primary closer to 38-40)
And trust that it's better for the motor power and drive pressure wise.

But one last question.
If I still get the "Turbosmart" in-cab boost controller, will getting it closer to a 50/50 split still technically be the best setup for over all power / drive??

Hoping to see maybe 65 ish total and the Primary making exactly half of that??



Thanks again for the help guys..

I've been curious as to how much this would actually help also. I think as long as the drive pressure is in check, it's probably OK to have the big turbo doing a lot of the work.

 

[Big Swole]

I've been curious as to how much this would actually help also. I think as long as the drive pressure is in check, it's probably OK to have the big turbo doing a lot of the work.

True!

I'll sacrafice a bit of power to stay safer and more reliable.

 

[RonA]

Mine run lopsided once they get over about 40psi. By 20psi I see around 8psi from the primary, at 50psi i see 30, and by 65-70 I see around 45 from the primary. I had similar results with the HTT 16cm SS housing on my old 64/71 but the 50mm external gate seems to make it slightly more pronounced. As long as you primary has a large turbine and large exducer on the compressor so it can handle the higher PR's, it seems to work well.

 

[Big Swole]

Mine run lopsided once they get over about 40psi. By 20psi I see around 8psi from the primary, at 50psi i see 30, and by 65-70 I see around 45 from the primary. I had similar results with the HTT 16cm SS housing on my old 64/71 but the 50mm external gate seems to make it slightly more pronounced. As long as you primary has a large turbine and large exducer on the compressor so it can handle the higher PR's, it seems to work well.

Okay Cool!
Thanks for the info Ron!!

My turbos are an 64/65/13 over an S475 ( 74.6/96/1.32 )

I guess I'll let my primary get the workout then..

 

[oldblue116]

I will be honest at first i was upset to see you start to paint the wheels bumpers etc black. Just because you very rarely see a 700+ hp truck that looks bone stock on the outside, but i must say you did it right and still looks very classy. After seeing some of your bad luck with these im glad to see you finally got a good runnning bad ass truck. Congrats !

 

[RonA]

Okay Cool!
Thanks for the info Ron!!

My turbos are an 64/65/13 over an S475 ( 74.6/96/1.32 )

I guess I'll let my primary get the workout then..

I've often wondered if high primary boost numbers could be related to the secondary charger not being able to move the air from the primary through the intercooler and into the engine causing the cold pipe to become a pressure vessel instead of a transfer pipe. Seems like something that could happen. My secondary is similar to yours in that the compressor is large for the size of the turbine. Seems like turbo's that are prone to surge as a single sometimes work well in compounds.

 

[Joesixpack]

Yeah, I'm not sure where the 50-50 thing came from but personally I make the most power working the primary as hard as I can. Bottom end though you want that gate locked down good.

I think it can be set up decent with a spring on the gate, but I gave up on that and went to a diaphragm pot actuator that references primary pressure.

The spring gate might be quicker on shifts though if your rpm's get low enough that you need to be into the secondary. I didn't find that to be a problem though 64/480.

 

[Big Swole]

I will be honest at first i was upset to see you start to paint the wheels bumpers etc black. Just because you very rarely see a 700+ hp truck that looks bone stock on the outside, but i must say you did it right and still looks very classy. After seeing some of your bad luck with these im glad to see you finally got a good runnning bad ass truck. Congrats !

Agreed. A lot of folks wanted to see me leave it completely stock looking.
I'm a Huge fan of "Sleepers" also, hence the reason the "Interceptor" stayed so stock looking.

The main reason I did the black out was because I'm such a Huge Silver fan that this Khaki really didn't interest me that much in the beginning. I almost refused to buy it soley on the color. And to be honest, wouldn't have bought it if it wasn't such a good deal.

But I started to look at pics on CF in the "Khaki Trucks" thread... The blacked out look really started growing on me. I REALLY like it now. I still think it sorta "Sleeperish" still. The black brought out the color a lot more.

But the Coolest part is with the Plasti Dip and the fact that I saved the stock Chrome Clad Alum. wheels, I can put it Right Back to the stock look in half a day.

Yes, my luck was not good with my 05. It was a real shame too because I did Love that truck and it ran Really Really well for short periods. I've very thankful to have this second chance though and I'm enjoying it. The Drive to go quicker and quicker with more power / lock up switch is still in me though... It's killing me to just leave it alone, but I know it's best for me right now.

Thanks man!!

I've often wondered if high primary boost numbers could be related to the secondary charger not being able to move the air from the primary through the intercooler and into the engine causing the cold pipe to become a pressure vessel instead of a transfer pipe. Seems like something that could happen. My secondary is similar to yours in that the compressor is large for the size of the turbine. Seems like turbo's that are prone to surge as a single sometimes work well in compounds.

This turbo "Map, sizing, Tuning, etc" thing is still way over my head. I've just not made myself try to learn and retain what I should about them. But for the most part, playing with it like this is teaching me a bit...I'll keep trying to get it right.

Thank you Sir!!

Yeah, I'm not sure where the 50-50 thing came from but personally I make the most power working the primary as hard as I can. Bottom end though you want that gate locked down good.

I think it can be set up decent with a spring on the gate, but I gave up on that and went to a diaphragm pot actuator that references primary pressure.

The spring gate might be quicker on shifts though if your rpm's get low enough that you need to be into the secondary. I didn't find that to be a problem though 64/480.

Very Interesting Chris!
I'm not sure on the 50/50 thing either. It's just what I've always heard and was told my Nathan at MPI about the kit that I bought from him for the "Interceptor". I think it may be More for keeping Drive Pressures in check than for make perfect HP for the setup.

I will try to do some with and without it completely clamped test going back to back runs in the 1/4....May be a week or so though. Gotta work the next 8 days in a row...

Thank you for the Info Sir!

 

[oldblue116]

yea im not such a big fan of the khaki color myself but with the black out it really turned the truck around and looks sweet. I just went to 3 different stores looking for the plasti dip and nobody has any.

 

[Big Swole]

yea im not such a big fan of the khaki color myself but with the black out it really turned the truck around and looks sweet. I just went to 3 different stores looking for the plasti dip and nobody has any.

Got mine a HomeDepot... But I'm sure it's very popular right now.
I'm not an internet buyer, I'm old school. But I bet someone has it on a site to order to your door.

 

[JQmile]

I've often wondered if high primary boost numbers could be related to the secondary charger not being able to move the air from the primary through the intercooler and into the engine causing the cold pipe to become a pressure vessel instead of a transfer pipe. Seems like something that could happen. My secondary is similar to yours in that the compressor is large for the size of the turbine. Seems like turbo's that are prone to surge as a single sometimes work well in compounds.

Most of it comes from the secondary not being small enough, and the primary not being large enough. The last truck I saw that seemed to match ratios at high power was Sean Gammel's truck at DPC a few years ago, which had a 58mm and 95mm. Problem is (or so I've heard) it's hard to keep bearing and shafts in turbos that small with the boost we're running. Eric Brown also made 1138rwhp with a 62mm and 95mm with a matched pressure ratio, but he bent the shaft on the 62. The atmospheric never saw more than 26psi.

 

[97rada]

That seems to be a great setup. The 62/95. Is it possible to upgrade the shaft much in the 62

 

[JQmile]

I think they make a 2.5 version of an S400 for the pullers. I'd use that, or a Garrett ball bearing. With the boost numbers that the mod pullers are running, I think almost all of them use a ball bearing turbo on the high pressure unit. They can handle the pressure and thrust loading better.