Slowxr6t

So iv got 19psi springs in my 50mm turbosmart wastegate and a long 2 inch stainless screamer pipe that goes under car beside the exhaust and exits just past the back door before the axles. I can hear the gate cracking open at 10psi sometimes earlier, full boost is 18-19psi. I figured there still must be way too much back pressure because of the stock mid and back exhaust. Iv been trying to keep the car as quiet as possible and my 4 inch dump pipe goes all the way to the first 3inch flange under the car where it reduces down to 3 inch. Iv still had the rest of the exhaust stock with mid and rear mufflers. I had the idea to replace the mid section and mid muffler with a straight 3 inch stainless mandrel bent pipe to maybe reduce back pressure even though the stock 3 inch splits into 2 2 and a quarter inch pipes then goes back to 3 inch and into the mid muffler which is straight through btw. The calculator tells you theres nothing to gain, but I have done it and I can tell you the flow increases quite a bit because I went back to the dyno to get some timing taken out of topend because the ecu has been shutting the throttle body down often after a pull because it senses a ping, we think because of slightly old or suspect 98 octane fuel. Anyway got on the dyno. Did a run with new 3 inch exhaust on and did 450kw and tuner said its lean, and we looked at fuel curve and it was lean all the way through rpm range. It had gone from .85 lambda to .75 or maybe even .70 lambda. I said to tuner exhaust is the only change iv made and we agreed it must be flowing more air through the engine and making it lean. So he fixed the fueling and took some timing out and now I have a much safer 430rwkw. It now has more power and torque under 3000rpm before gate starts ooening so its better down low with freer flowing exhaust and no drone and screamer pipe is not as loud either because more flow through main exhaust. It is louder at idle and on cruise but its fine, not bad at all. So stock fgx mid section is a bit restrictive boys and girls.

I have an artec manifold and 50mm gate and I made a 2 inch stainless screamer pipe that is really long and exits onto the ground just past the back door so its 100 % legal, the first one I made exited about halfway along under the drivers door and was scary loud, sometimes I got a fright when the gate cracked open. My extra long pipe actually sounds a lot quieter surprisingly and sounds real cooool.

So I started having this problem with losing boost after a thrash, it peaks at 17-18psi and it would randomly only boost to max of 4psi. No check engine lights. If I pulled over and turned engine off for a minute and went again it was back to normal, It did this to me several times and I thought it might have been a faulty sensor. I put in some fresh 98 and went for a drive with my tuner and he had his computer plugged into my ecu and I couldnt get it to fault. So I think the oldish fuel it had in it may have been not good enough and it was doing some detonation and the ecu was closing down the throttle plate causing low boost. And resetting itself once switched off and re-started. It hasnt done it since putting in new 98 fuel.

The borg efr9174 t4 1.05 im running, I am very impressed by its spool and power compared to the gen2 gtx3582r I tried on the stock manifold and even the gt3582r . At 2500rpm the gt3582r doing 16psi had 575nm torque, the gtx at18psi had 450nm, the borg 18psi had 515nm. At 2800 rpm gt peaked at 800nm, gtx 535nm, borg 565nm, 3500rpm gtx peaked at 865nm, borg 840nm, gtx catches borg at 3200rpm when they both have 600nm. 5000rpm gtx 775nm, borg 780, 5500rpm gtx 735mm, borg 760nm. 5800rpm gtx doing 432kw, borg 450kw. Gtx and borg Similar curves but borg has more under 3000rpm and I can feel the extra torque on the road. At 3250 both are doing 650nm. The gtx had a slight whistle on cruise which was a bit annoying. I like borg because it is high mount and looks cooler. Theres a comparison. Cheers guys.

So I took dump, waste gate screamer, heat sheilds and water and oil lines off turbo, removed manifold and turbo as one piece and found bad exhaust leaks on both ends of the Artec manifold. It was still all done up tight and couldnt come loose because I had atomic anchorlox nuts holding it on. Manifold flange is badly warped, banana ed. Very disappointing. Anyway I rang the retailer and they got hold of Artec and lots of photos and emails later Artec sent me a brand new manifold, this one has a flat flange, I checked it. I didnt check the first one when I first got it but it didnt leak until 1500ish kms. So iv installed it all again, I bought new Tinnix inconel studs and new atomic anchorlox nuts and its all go again. I had to send my old warped manifold back. Thankyou Artec for coming to the party.

@tofski yea it sucks alright, I didnt check it for flatness when I got it, it may have been warped from new. Are you building a drag monster? That is insane power you have. Was it a full custom manifold you have or a j pipe off the stock nanifold? I was thinking of cutting off t3 flange off stock manifold and getting a t4 split flange welded on but clearances looked a bit tricky. Then this Artec came up cheap. Pretty certain retailer didnt know there was anything wrong with it. They just wanted to cash up and get stock gone. I hope if Artec give me another one it is identical because if not il have to do fab adjustments which is never fun. Otherwise il go 6 boost or sinco and have to remake everything.

@tofski @Vigilance99 efr9174, the 91 is conpressor exd big side and the 74 is turbine 74mm exducer, that's the small side of turbine.

Good on ya mate

Cheers for that

@Vigilance99my efr has a t4 split pulse flange 1.05 a/r housing, its not small, compressor wheel is 67mm inducer and 91 exducer, 900hp turbo, im getting 10psi at 2500rpm and 17-18 at 3500 I think, its a great road turbo with gobs of torque down low and minimal lag. My Artec has a warped flange at the moment and im trying to get Artec to replace it. Check my posts. @tofski did you get a 6 boost? check my above post.

@hjtrbo and whoever wants to know haha, I disassembled my car, dump off heatsheilds off, gate off, turbo and manifold off together and found my new Artec manifold has a pretty badly warped flange, its 12mm thick and still warped, with a straight edge lying on it, I can get a 1.4mm thick steel ruler in both ends, more so the firewall end, and theres soot marks blown thru the sides, pretty ugly! Im surprised it sealed as well as it did, it must have pulled in at the ends a bit when it was bolted up on car. I contacted the retailer and sent them photos of it all and they have contacted Artec to try get a replacement manifold. Pretty damn disapointing but hey welcome to motorsport! If they dont come to the party I might go for a 6 boost or Sinco. Also my sump is still leaking and with manifold off we can see pretty much whole area where leak is. We cant tell where its coming from and it almost looks like the sump is porous and its soaking through the alluminium. Is that even possible??? Weve just resealed the *beep* of a thing back on and its exactly the same as before.

What brand is it? 6 piston? 355mm rotors? Are they awesome, hows cold stopping? I got 6 piston brembos with brembo pads and 355mm dba slotted rotors, they shuddered and had to get them machined which was not cool. But they are awesome now, huge braking power.

What motor is in the caprice? Do you make your living being a back yard mechanic? Are you busy on customers cars usually and do you advertise or is it just word of mouth, go to puffwagons garage? Hes a legend.

Shouldve brake checkd him. Nah prob not the best idea. He was a road rager for sure.