A few months ago after finally getting my dssracing forged bottomend broken in and tuned. My tuner and I found that I had excessive backpressure for a fairly simple 3' exhaust. I was peaking about 8lbs of pressure at my wideband location and that was with my dtp rear dump open. I hit a max 699whp and 650tq @ 19lbs boost with 50/50 water/meth on 94 pump gas. EVERYONE was blaming the poor On3turbo as the culprit for my less than stellar numbers and poor turbo efficiency.

I made a few threads about upping my exhaust flow and came up with adding a larger 4' cutout at the rear...and adding a fender exit 2.5 loudvalve right off the turbo to add in ridding the backpressure. I must say the loudvalve was an instant response in performance. The car flatout was making more boost early and unruly torque. I tried to make a pass and did some street pulls which netted me a leaking rear axle. Since then I fixed the axle..switched to a Lingenfelter 2 step to replace my old msd unit and build more boost off the line,and a linelock. My tuner saw video clips of me booting around and knew I needed dyno time.

Which brings me to yesterdays events. I had time off to make it over to Champion motors and strap the car down. With no changes to the tune..we saw immediate gains at 14lbs especially the midrange hp and torque! At the end of it,for the first time..the flame shot a hot flame from the fender and I was happy. 19psi peak made 766hp/811tq, 92% duty on my deka #80s, and my aeromotive fuel regulator isn boost referenced yet..set to 58lbs. There is more in it we figure adding more fuel uptop,a splash more boost and crack 800whp. Checkout the video and some other cars while I was there for the day.

 

That's pretty cool. I have been eyeing those for a while now, but more for sound than anything since I have a stock 4.8 LR4. But my Borla already has the provision for a "cutout" and the car is pretty quiet through the muffler. I like the idea I can have stock sound for traffic and I can get some noise out of it if I put my foot down more.

 

Man, huge gains. It just gets more and more powerful as you get it figured out.

 

That's wicked powerful for a nice street cruiser Very nice!!

 

Im happy and sad at the sametime.The car itself is holding up and becoming more efficient at making power..but it sucks because winter is here and I havent been out to play with it much and spank stuff street/strip. But this gives me time to really start saving up for a proper diff.Im leaning heavily to a s60. I emailed the owner of dssracing to let him know my ls forged piston/rod setup has made good power and showed no sign of hitting max potential yet. he assured me 900hp crank would be where id want to back off since i didnt upgrade to better rods for higher boost. I know before my next visit to the track..I gotta put a harness bar in,and a harness and seat. Then work on building a more efficient cold side with next to no couplers.Tired of charge pipe leaks/popping off. I think 5 more lbs and the car would clear 800whp on 94 pump gas.I think the car with good diff should be 10s easy,,maybe high 9s.And it scares the F**L outta me full tilt! Lol

Loud valve is amazing...it really woke the turbo up..from "quiet" to ***** deep roaring power back to quiet when i lift off the throttle.Highly recommend them.

 

Veeery cool, great numbers!. Would have been nifty to shoot flames out of the factory side fender vents! (a new stainless opening would be needed to not melt that plastic tho)

 

Originally I was going to do that but I was concerned that the bends id need would essentially impede flow. I didnt want to take a chance of all that effort and still hurt the backpressure issues i was getting.