SPS 62 in twins. Drive pressure reduction?

[Diesel Freak]

lol, it made a bad situation worse!!

 

[paulb]

I like Cliff's approach, pick a power and build to it... ... ... I'm still trying to pick that power and keep it a street truck.



Jim

I gave up on picking a power... :-laf So I have settled on picking a range of power. I race under three different E. T. limits. One track I race at (Boise, ID), limits the Sportman class to 14. 00 and slower. The rest of Division 6 allows 13. 00 and slower (including my home track, Medford, OR). I also race at some Division 7 tracks that allow 12. 00 and slower. My personal preference is to run at the quicker end of the class. So... At Boise I run with the Comp off and run ~14. 6's. The rest of division 6 I run with the Comp on 3x5, and run ~13. 49's. For Division 7, I run with the Comp on 5x5 and run ~12. 7's.



This means that I routinely adjust from ~370hp, to ~565hp, and I still need quick spool and low EGT's, and consistent hp at all those power levels. I do not want to have to change my turbo setup for these different power levels. Not to mention I pull my travel trailer to a lot of the races... That is what I am tuning for. Before this season starts I have plans to be at ~630hp and run ~12. 5's. Oo.





Oh, yeah. . Back to topic... Ron, did you try adjusting the wastegate again?



Paul

 

[Diesel Freak]

I only have two power levels.



Continuous and Peak (see sig)



The problem is, my combo (Mach 4 injectors and EZ) makes more than the sustainable 353 that my HX40 can support.



Once I turn on the Blue Box, Holy Smokes Batman, 38 to 40 psi of boost and thermonuclear EGT.



lol



Ron, how do you have the wastgate on the K31 set?

 

[RonA]

One nice thing about twins. I only made 480 with the cam plate I used. But after 10 seconds i 0nly hit 1200.



DF. the wastegate was set from the factory at 30psi. It creeps open a bit sooner.

 

[RonA]

I still haven't seen much data on the SPS62. I decided to take a chance and have II bump the fueling up on a new pump I picked up. The old pump is being traded for a new SPS62 set up for twins. I'm keeping my fingers crossed that it will bring down the drive pressure. I changed injectors recently and swapped my 80 psi gauge for a 100. At 65 psi overall i hit 95 at the exhaust manifold. I won't be doing that anymore.

 

[AK RAM]

I sent my S300 to HTT for some drive pressure relief tweaks. Had the turbo rebuilt with better bearings, enlarged wastegate volutes/flappers (claim 30% better flow), few machining/quick spool mods, clipped exhaust wheel, and fitted with a wastegate cover spacer so the arm can move full travel and flappers completely up and out of the way. $210 for everything with same day turn-around. I was impressed. I just got it back yesterday. Won’t be long….

 

[BradyWilliams]

Larger Compressor Wheels slow compressor/turbine speed down. Larger Turbine wheels can and will increase compressor/turbine speed but must be matched correctly. Clipping turbine blades slows Compressor/turbine speed because the driving edge of the turbine blade is being ground away. In the right situation clipping does give some benefit but is more favorable in gas turbo applications. We believe that lower drive pressure is a virtue when building a twin set. Therefore Our Super Phat Shaft turbos would always be a Great choice to make a twin set. We do have Inventory available if you are interested. Thanks, Brady 1-800-955-0476 www.industrialinjection.com

 

[Diesel Freak]

GEE Whiz!!!



II, do you have any shame?



This is a decent thread without you trying to sell us something!!!

 

[RonA]

I find it interesting that II has given plenty of info on this thread, and you have just given more of your usual techo-babble. My question was," SPS 62 in twins. Drive pressure reduction?" The answer from II, yes. Followed by supporting data. You answered my question with another question. You knew what I was talking about when I said I wanted to lower my drive pressure. Want to help this thread? Give some usable information. I am in no way bothered by II putting in a word for their product. I have already decided to get one.

 

[JStieger]

Ron-



I've been collecting data on my 3rd gen and posted a boost versus drive pressure graph in this thread



I've also constructed a "turbo spool comparison" showing how different turbos affect the time going from say 100 HP to 350 HP, i. e. the low end off the line so-to-speak in this thread



I haven't updated the spool time table with yesterday's dynos, but a quick calculation shows 0. 1 to 0. 2 second faster spool from 100 HP to 350 HP with the SPS 62 versus the 66. This is about par, maybe a hair above, than the HTB2 62/14, but with better drive pressures.



I'm interested in what you're doing because ultimately I want to use this turbo in a twin set.

 

[RonA]

I thank you for the link. I have been watching your thread. Very interesting. I hope it works well for me also. 3rd gens are a different species when it comes to fueling and turbos though. The biggest thing i have noticed is the hp to boost numbers. Seems like they make alot more power per lb of boost, and spool turbos much harder than either p7100s or vp44s.

 

[BIG BOB]

There is a lot of knowledgable people on this thread and I would like to ask a question about "drive pressure" and not be considered hijacking this tread. I know that everyone has said that we want a 1:1 ratio on drive vs boost numbers.



I have a B1-2-04, and Hot Juice with Attitude on Ghost Rider. I was running the Edge elbow and my drive pressure were above 65 with 40#'s of boost, I changed back to the stock elbow and drive pressure went to 52 while boost stayed at 39-40. Would 52#'s of drive pressures still be considered too high?



Thanks in advance!

 

[RonA]

JStieger.

Looking at 3rd gen dyno graphs is definitely different. They don't spike as fast up or down.

Big Bob.

52 at 40 doesn't seem real bad. I think it is just the byproduct of whatever they do to that turbo to make it spool quicker for the auto truck.

Ron

 

[RonA]

I was going to order the turbo without the twins mod, but Shane talked me into having it done. I will probably have it next week some time. It will be nice to see a little more activity from the primary boost gauge and a little less activity from the drive pressure gauge.

 

[rivercat]

Can I ask what is the twins mod? Im twins curious. also what would be the best primary to put under my ps62 or sps62 if I have it upgraded?
What sticks would be minimum to spool these?

 

[RonA]

As I understand it the twins mod is enlarging the wastegate openings and modifying the linkage to allow it to open farther. I should be getting mine around wednesday of next week. I am hoping to see around 30psi reduction in drive pressure. That would bring me down to 65/65. Hopefully i will see a hp increase and a bit more air out of my primary. I have heard that the larger housing should be wastegated a bit higher than the small housing. I'll start around 30 psi.

 

[RonA]

The SPS62 arrived today. Excellent packing job. It looks like it will fit. The wastegate mod won't effect me. The length from the mounting flange to the center of the Marmon flange is what's important for me. If its longer it will be tough. It measures close to the same. I got a call saying they finished my new injection pump today also. Should have it in tomorrow morning.

 

[RonA]

I installed the SPS62 today on top of my k31. Drive pressure is reduced but it takes alot longer to spool.

 

[mattymac]

How much less DP? Also EGT reduction?

 

[RonA]

It will take a few days to get that info mattymac. I need to hook up a regulator to the line going to the actuator to control how much the wastegate opens. It's a bit larger than what I had and it opens farther.



Ron