I had been doing about 17 PSIG boost with my 185 crank pulley until it blew up in traffic at 25 MPH. That was the second failure of the LET design, ENUF!

Put the stocker crank pulley back on and was seeing about 11 PSIG. With assistance from ROB I purchased another S/C pulley sized at 65 mm as my upgrade replacement.

When this was installed with new idlers ( My pulley savers design of course ) in similar climatic conditions again on a flat surface the boost read out at 15 PSIG. This is my reading at my intake manifold NOT THE WYE. Real pressure, and I was happy with that. Correcting for the restriction of the factory manifolds that would be a reading of 19 PSIG due to the approximately 4 PSIG restriction the S/C sees.

All in all I like it and enjoy the lower speed accessories ( alt. water pump, power steering, and a/c pulley = i.e. a bit less paracitic loss at lower rpm )

So what is not to like??????? ENJOY THE CHRISTMAS SEASON YALL WDY

 

So s 185 crank on makes about 2psi more than a 65

 

I saw 14.7 psi max, all stock if memory serves me correctly. 17 psi max, with a 65mm pulley. 19 psi max, with a 178 crank pulley and large manifolds. 178 stacked with a 65 .... I can't remember but the overboost code was thrown so 22 psi or more. All at close to sea level and over 80º. I have no experience with a 185 or the Crossover manifolds. I'm still on the fence considering the Crossovers.

Les

 

Wish i could stack something with thjs 62 I see tad over 20 psi but more low end grunt is welcome

 

Me too Les. Someone brought up a good point about adding crossovers and lowering boost in another thread. The crossovers increase air flow but lower boost. Well, our ecu can't measure airflow. It calculates it using boost pressure and throttle position. Less boost equals less fuel. Just something to chew on....

 

I have no fuel issue, remember that the lower boost ( a small deviation % wise ) also allows MORE FUEL as the pressure differental versus the rail pressure is smaller. The fuel is not restricted by the higher boost, using stock manifolds so the trade off is better using the lower restriction cross over manifolds. More to follow with improving weather. Enjoy Woody

 

Hi Woddy, as the weather got better ... - I’m very interested in your results. What is your AFR (your ecu is stock?)? What is your ltft? Does ltft shift according your driving style (low/high rpm)?

 

I've read - the (stock) fuel pressure regulator tries to keep a constant over-pressure.
From which location becomes the fpr its information about pressure level (its a tube, so not the map-sensor-value!?) before or behind the (former) restriction (Y)?
If behind, the lower indicated map-boost at least works not "mechanically" against you.

 

Stock regulator is referenced to the atmosphere and not the engine or its boost. I made up an analog "computer" out of a fuel pressure regulator to add fuel pressure above some value of boost. I chose 15 psi as my starting point and above 15psi the fuel rail pressure increases a psi for each pound of boost above my chosen value of 15. Thus at 18 psi boost the rail increases 3 psi etc.to keep A/F in line with one another. Enjoy Woody

 

Thanks - that sounds interesting. So in closed loop the system works almost as stock (with possibly the same fuel pressure) and nonetheless you can control your afr at wot at high rpms.
Can you buy this system from needswings with a manual how to install and how to "programm"?
If - with the crossovers - the boost level don't exceeds 15 psi with a 65mm pulley, you probably don't need a tune (for savety-reasons). You just set your entry boost-level (perhaps 9 or 12 psi) at your fpr - and watch if afr is fine.

 

Check with Rob at needswings, I gave him my design and the information and I believe he still has the kit for sale, to dynamically assist the F/A mixture under hi boost, Woody