URD Stealth 2.7 and 2.55" pulleys ready to ship

[grifter95]

Digging up an old post I know. But getting the Tacoma back within days after the connecting rod let go and exited the engine via the oil pan. Well months later the engine is almost back together after being rebuilt with forged pistons, rods, ARP studs, new bearings, valve job, etc. Currently have the NST + URD 2.8 + a little nitrous. Thinking about pulling the nitrous and adding a 2.55 pulley. Truck is an 2009 so I'm running MAP-ECU3 and a 7th injector. Can I run that small of a pulley? Maybe need to add some methanol?

 

[Gadget]

We have never tested combining our pulleys with the NST overdrive crank pulley.

You might be pushing that supercharger a little to far with that combo. If you do move forward, proceed very carefully.

G

 

[TommyXrunner]

Digging up an old post I know. But getting the Tacoma back within days after the connecting rod let go and exited the engine via the oil pan. Well months later the engine is almost back together after being rebuilt with forged pistons, rods, ARP studs, new bearings, valve job, etc. Currently have the NST + URD 2.8 + a little nitrous. Thinking about pulling the nitrous and adding a 2.55 pulley. Truck is an 2009 so I'm running MAP-ECU3 and a 7th injector. Can I run that small of a pulley? Maybe need to add some methanol?

i would say that you should sell the 2.8 and the nst lowers and just put on the 2.55. i think someone once said that the 2.55 should get about 1 psi more than the 2.8+NST's

i also remember a thread saying that they made more power with the trd s/c at 12psi than they did at 14psi on a day to day basis from to much heat soak

 

[grifter95]

With current setup and long tubes I'm only at 9psi at sea level. 2.5 would put me back around 12. Maybe the 2.7? Put me around 10-10.5 psi. Just thinking. Twin turboed gto has gotten me addicted to FAST.

 

[TommyXrunner]

With current setup and long tubes I'm only at 9psi at sea level. 2.5 would put me back around 12. Maybe the 2.7? Put me around 10-10.5 psi. Just thinking. Twin turboed gto has gotten me addicted to FAST.

haha well than i'd say sell the blower and go turbo since you already have a built motor!

 

[Whitebeauty]

I'm already at the brink with my setup. 2.6 and Overdrive kit as well. Stiegemeier stated that that's just right there. For the spinning of the rotor packs.

 

[grifter95]

I'm already at the brink with my setup. 2.6 and Overdrive kit as well. Stiegemeier stated that that's just right there. For the spinning of the rotor packs.

You are on the limit of the blower or the engine? I know my engine is jam up, so I am looking to make the most power possible safely. Guessing I can go up in boost and add methanol/water mix into the blower like I was injecting the nitrous. Should do well with keeping temps down coupled with the factory inter-cooler.

 

[Whitebeauty]

Blower..............

 

[grifter95]

So I should be able to squeak by with the NST + 2.7? Or could the 2.55 be the max? Not sure how to figure the blower speeds vs pulley size. 5800 rpm max (auto)

 

[Whitebeauty]

I forgot what it was but I think u multiply upper with lower diameters n it should give u the speed the rotorpacks would be spinning... oh yeahni forgot the rpm that goes in there somewhere... well n e ways I know with my setup I believe im in the 18 or 19 krpm.

 

[trdtoy]

Crank pulley diameter / s/c pulley diameter x engine rpm = s/c rpm

I think nst crank pulley is 175mm or 6.89 in.

6.89/2.55= 2.70
2.702 x 5800= 15,672rpm
push this to 6200rpm engine and you get 16,752rpm from s/c.

Your current 2.825" urd pulley with nst should be around 14,146rpm s/c. If 9psi with current setup you could expect around 11-12psi IF you can keep the s/c outlet temps close to same with current setup. Water/meth does wonders but as you may know nitrous will cool things better! Lol!

Not sure what rpm limit is on the s/c but I think you will be ok at those engine rpms imo. I think the steady state rpm limit is 12-14k and intermittent rpm up to 16-18k.....

I ran a 1.8" s/c pulley on my trd s/c I had on my 5vz! Talking bout screaming! But she made some heat too! Over 19k s/c rpm at redline and 14-15psi with water/meth. Power was better down low than a 2-2.1" pulley(10-12psi) but up top not a huge difference. Too much heat is built up top from the s/c, limiting power. Even running water injection and 93 octane on that setup I had to pull a good bit of timing to stay away from knock. I ran this for a short time before going turbo. Due to overall efficiency difference with turbo i made much more power than I did with the s/c. Of course the efficiency was drastic... S/c around 30% and turbo around 70% adbiatic efficiency so clearly s/c made much more heat. Only place s/c had the advantage was below 2k rpm where turbo was not making full boost yet.

 

[TRON]

Does anyone know what the rpm limit is on the trd blower?

 

[Whitebeauty]

Use the post above u for that info that's just about the same info I got from APR n Stiegemier. N we stuck to it.

 

[TRON]

Yeah... Seems like 18 is the high looking at the little information there is pertaining to rpm limits and this blower. APR should know better than most; I mean they have a trd engineer. Intiniri was the only person I know that actually ran the nst and 2.7 close to sea level and actually raced it daily.

 

[Whitebeauty]

Hopefully I get mine done before the end of the year n we can see what that 2.6 n NST does. Right now APR is doing my heads so I'm starting from there n working my way down.