Another SPS66 towing opinion...

[Jeff_K]

Ahhh, well if its for twins then its OK

 

[JStieger]

Ahhh, well if its for twins then its OK

Well, for some reason I am now thinking about the Coors Light commercial with the 2 blonds... . ahhhh, twinnnns!

 

[RWood]

Are you going to have to change the whole turbo or just the wheel and housing?

 

[JStieger]

Are you going to have to change the whole turbo or just the wheel and housing?

Stay tuned! I'll let you know after Friday

 

[Jeff_K]

Well, for some reason I am now thinking about the Coors Light commercial with the 2 blonds... . ahhhh, twinnnns!

Yeah, two are better than one!!

 

[Hohn]

Please explain this in further, not sure how this could happen. Is it possibly due to later injection causes higher EGT's?

Combustion generates hot, rapidly expanding gases. The longer they are expanding, the less they have LEFT to expand, and the cooler they are.

Early timing cools EGTS and more of the expansion goes into driving the piston down.

Late timing means not enough time for complete combustion, and higher EGTs. But it also provides a lot more drive energy for the turbo.


The late timing trick is something a lot of the turbo Buick racers do. Really late timing off boost, then it goes back to normal once the turbo lights. This really cuts lag and helps 1/4 times.

jh

 

[RTillery]

You guys are killin' me. I just walked out of Industrial Injection last night with a new 62/12 whistle pig under my arm. I have been carrying it around like that guy on "Dirty Jobs" showing everybody I called on today.



I won't get home til this weekend and probably won't have a chance to install it til after the 1st of the year. Is this thing pretty much a bolt on for a 6speed? Thats what I have been told but any insight from the experts is much appreciated.

 

[mattymac]

Yep it should just drop right in.

 

[Tomeygun]

When I had the 62/14 the cam really made the low rpm range really fun in terms of "pullability" and now with the 66/14 I feel that I lost some of this fun factor in terms of having to watch throttle position all the time to prevent the surge.

So you are getting surging problems with the Super Phat Shaft 66?



I have never had even a hint of surge with my Sledpuller66 - Is your surge due to the Cam maybe?



I just hate when your have two stick-shift trucks, both 66mm turbos, and one surges and one not... Why I ask !?!

 

[JCleary]

So you are getting surging problems with the Super Phat Shaft 66?



I have never had even a hint of surge with my Sledpuller66 - Is your surge due to the Cam maybe?



I just hate when your have two stick-shift trucks, both 66mm turbos, and one surges and one not... Why I ask !?!

I hope I'm in the non-surging camp when I find time to install this turbo...

 

[hasselbach]

Mine only surges when I have 10,000 behind my truck and I am really low in the rpms in 6th gear. . but only very little



If one 66 is good, then 2 on your work bench just has to be better. .

 

[JStieger]

So you are getting surging problems with the Super Phat Shaft 66?



I have never had even a hint of surge with my Sledpuller66 - Is your surge due to the Cam maybe?



I just hate when your have two stick-shift trucks, both 66mm turbos, and one surges and one not... Why I ask !?!

It all boils down to different driving styles.



The surge which seems minor compared to what others have reported was not noticed until I started towing more seriously. Normally these 3rd gens sweet spot is around 2000-2100 rpm. Normally I just short shift instead of winding the truck out to 3000 rpm. So when I did the short shift towing or didn't shift and let the motor lug down a bit and pull, I would get a shudder, cha-cha-cha, woof, woof sound that was real faint. Then as the rpms came up it went away. Subsequent to this, if I was empty and on an uphill interstate on-ramp or going up a small hill and short shifted due to traffic in front of me I could get the surge. If no one was in front, then all bets are off and it's rocket ship time!



Now back when I got the cam it allowed a bit more useable rpm down low where I could definitely feel the truck start pulling. About 2 weeks ago I posted a bunch of spool-up times from say 100 HP to 350 HP for various turbos and mods I've run and the cam definitely showed quicker spool up for the same turbo and same mod (boxes) otherwise. The spool times increased as I went to a bigger turbo, but were still better than stock.



The surge that I've experienced is at lower rpms than what others experienced. The cam allows the engine to breathe better at all rpms including lower as it increases the volumetric efficiency of the engine. At a certain rpm the engine can only consume so much air. If the turbo is producing even a hair more air than what the engine can consume you get surging (or in the extreme case barking). So if one increases the volumetric efficiency of the engine, they increase the amount of air that it can consume. On the same token, if I can get the engine to breathe lower in the rpm then the sooner the ECM will fuel and get the turbo spooling. It's a catch-22, but anyone with a cam will tell you that a cam is all positives... if you did a search on this site for people that have installed cams you will see that a common theme is that the came made a bigger turbo perform like the next size turbo down...



Now with the cam + SPS 66 combo I have something that my various dynos show spools better than stock (here), but the surging counteracts some of the low end use that the cam brought. However, on the mid-to top end it's all icing on the cake with the cooling!



If I was just dynoing, drag racing, and sled pulling only then the SPS 66 is the turbo for me. Throw towing into the mix and it's different for me because I don't drive like I'm dynoing, drag racing, or sled pulling. It's all about setting up my truck for its realistic uses. Different people have different goals and driving habits.



Anyhow, things will get squared away this Friday! I'm pretty excited about it after talking to Brady and Shane today!



BTW, if I was to rank the best mods I've done to my truck in terms of all-around utility and performance they would be:



1) cam

2) cam

3) cam

4) injectors

5) turbo in #1 through #4

6) FE clutch in #1 through #5

 

[Tomeygun]

Mine only surges when I have 10,000 behind my truck and I am really low in the rpms in 6th gear. . but only very little



If one 66 is good, then 2 on your work bench just has to be better. .

LUCKY!!!!!!!!!!!!!!!1

 

[RWood]

JStieger,

Do you have to send the turbo back of are they sending you different parts?

Thanks,

 

[JStieger]

JStieger,

Do you have to send the turbo back of are they sending you different parts?

Thanks,

I know that with some of my other friends that have modified turbos that the vendor will either ship a new turbo in exchange or the parts to modify the current turbo if they believe you can tackle the job. In my view, I already have a great turbo base in the SPS design so it would be great to retain this feature...



With this in mind I drove over to Salt Lake City this evening after work and will be heading over to their shop first thing in the morning. I'm only 3 hours down the interstate from their shop and they have a nice heated shop as opposed to me doing work under stealth cover in my apartment complex. SLC is a big city for me and I usually make a trip out of it - must see Cabelas superstore... strong pull...



Anyhow, we discussed some different options through PMs and phone calls that all look good, but I will finalize the decision in the morning... I'll keep you posted!

 

[JStieger]

Anyhow, we discussed some different options through PMs and phone calls that all look good, but I will finalize the decision in the morning... I'll keep you posted!

The resolution will be in my new thread called:



"Prototype" Super Phat Shaft 62 :-laf

I have never had even a hint of surge with my Sledpuller66 - Is your surge due to the Cam maybe?



I just hate when your have two stick-shift trucks, both 66mm turbos, and one surges and one not... Why I ask !?!

Shane Williams insisted that we go for a ride in his dad's (Brady) truck as it doesn't have the 66 surge. I was pretty skeptical, but after putting it through the various driving scenarios where I experienced surge as well where others experienced surge, there was no surge! Nada... zip... ! Lots of 3rd gens are set-up different and each owner drives their rig a bit differently.

 

[hasselbach]

"Prototype" Super Phat Shaft 62 :-laf

So its that a PSPS 62??

 

[JStieger]

So its that a PSPS 62??

No... it's a Pre-Production Prototype Super Phat Shaft 62



PPPSPS 62



Seriously, though, I saw a box with your name on it in the shipping area as well your dismantled 1st 66 turbo on the tech's work bench...

 

[hasselbach]

No... it's a Pre-Production Prototype Super Phat Shaft 62



PPPSPS 62



Seriously, though, I saw a box with your name on it in the shipping area as well your dismantled 1st 66 turbo on the tech's work bench...

WHAT???????? THEY TOOK APART MY SPS 66?????



oh yeah. . that's the one that had the woof woof problem. Brady and I are very interested in what was making it behave so poorly.



I am very interested in this hybred 62 unit of yours. Keep us informed of the performance. It sounds great.