djz Posted March 18, 2009 Author Share Posted March 18, 2009 I take it you are running edis? Nice distributer cover;) Hey, thanks I had to have something to cover up the hole. I'm running a standard L20ET optical distributor with a Z31 chopper wheel, the computer handles the rest, the ignitor is on the right hand inner guard next to the coils. Quote Link to comment Share on other sites More sharing options...
djz Posted March 18, 2009 Author Share Posted March 18, 2009 Several have already mentioned it, but...Airflow, Airflow and Airflow. The exhaust is a problem, and have you done any work on that intake manifold? There are usually several casting protrusions into the plenum and the runners that make for funky flow characteristics, and how big is that TB again? Also, I'm not sure there's much you can do about it short of modifying the end tanks, but that IC design is requiring more tight 90's in the plumbing than I'd like to see. Have you measured the air temps at the intake manifold? It would help to know what air temps you are seeing at WOT and full boost. I see that you are running a heatshield between the intake and exhaust manifold which is good, but your air filter placement is drawing hot air from the engine compartment and making your IC have to work that much harder to get the temps back down. I know that this is also not that easy to solve, but your crossflow IC should leave some room to draw the air from the front. It would be good to have a wideband for tuning the AFRs, too. What are you currently using for an EGO sensor? Have you checked the timing on that reground cam? That IS a good looking ZX, BTW! Hey, thanks. I've been sorting out the bits and pieces today so I can build a new exhaust on the weekend, then I'll try and get it back on the dyno the weekend after. The inlet manifold had the ports matched to the gasket, but not that far up the runners, other than that it is stock, the throttlebody is small. I'm working on building a new manifold with a much bigger throttlebody. I didn't really notice much of a change when I went from my old intercooler with 2 less 90 degree bends to the current one I'm using, I know its probably not the best flowing thing in the world. I'm not sure about air temps, next time I take the car out for a good run I'll monitor them and let you know. The air filter placement is tricky, I can't really cut up the radiator support any further without causing trouble when my car gets inspected every 6 months so I've just had to leave it like it is. The engine was dyno tuned with a wideband sensor in the downpipe, I don't run one on the car normally as I don't like playing with the tuning myself. The cam timing is one thing that I haven't had a good chance to play with, it seems to run better with the cam pulley in position 3 instead of 1, but I really need to get around to degreeing it properly and getting an adjustable cam pulley. Quote Link to comment Share on other sites More sharing options...
Chris240zTurbo Posted March 18, 2009 Share Posted March 18, 2009 a 2.5" crush bent exhaust? that right there is killing any chance of making decent top end power, you'll pick up a bunch of top end HP going to a 3" mandrel bent set up with a straight through drag type muffler, I like dynomax, cheap and seems to work fine. I wouldn't be a bit surprised to see your combo pick up 40-50 WHP up top with a decent exhaust. Your timing map is also very conservative after 105kpa, by several degrees, have you run an EGT on the engine? I bet they're high with that much retard... I'd do the exhaust first, 2.5" is way small for a stroker turbo, and the crush bends are no good for sure. Try to bump up the timing after 105kpa a few degrees at a time while on the dyno, I bet you'll be closer to 20-24* under max boost as long as your AFRs and EGT are in line. Others have said the intake manifold and TB, and also the pretty severe bends in the I/C system, which are for sure leaving some power on the table also. just for bench racer sake, I built a friend a very mild turbo set up a few years ago, totally stock junkyard L28ET, Haltech E6S, 440CC injectors, a modified starion I/C, 60mm T/B, 2.5 mandrel downpipe into a 3" mandrel exhaust, dyno max muff, and a 57 trim T3-T4 turbo with a .63 turbine, and made 280ish WHP and 290WTQ at 17 psi, your combo should make much much more power than that, you just need to remove the bottlenecks to airflow, the biggest I can see is the exhaust for sure... Quote Link to comment Share on other sites More sharing options...
thehelix112 Posted March 18, 2009 Share Posted March 18, 2009 I'd also probably do something about the external wastegate thats pumping extremely hot exhaust gases at the turbine outlet flange, not to mention everywhere in the engine bay, possibly including the air filter. Dave Quote Link to comment Share on other sites More sharing options...
Kash Posted March 19, 2009 Share Posted March 19, 2009 What compression ratio are you running? Just got done with my 3.1 stroker turbo build with similar spec's except for I'm running the stock 90a cam and my seat of the pants dyno puts it at about 250 hp at 12psi. Im running a JWT z31 tuned ECU wth a 8.3 CR... Quote Link to comment Share on other sites More sharing options...
djz Posted March 19, 2009 Author Share Posted March 19, 2009 I'll sort out the wastegate at some stage, it's far enough away from the air filter that I don't think it would be affecting it that much, the dyno runs were done with the bonnet open and a big fan in front of the car. Kash - the compression ratio is approximately 8.5/8.6:1, the head was skimmed and the block was skimmed very slightly. What turbo are you running? Quote Link to comment Share on other sites More sharing options...
ktm Posted March 19, 2009 Share Posted March 19, 2009 I figured your compression would be higher than many of us running a stock L28ET block. However, I would review the Megasquirt forum and look at the sticky at the top of the page that talks about map sharing. There are a couple guys running turbo flat top builds at 15 psi who are running north of 17 degrees of timing at 15 psi. Your timing map, as I stated early on, also looks quite odd. Usually you do not jump 4 degrees of timing before and then after peak torque. It is a steady increase that is typically 1 degree per 1000 rpm after peak torque and a bit more rapid before. Again, check the MS forum and look at some of the maps on there. This is in addition to changing out that exhaust! Quote Link to comment Share on other sites More sharing options...
Daeron Posted March 19, 2009 Share Posted March 19, 2009 Your dual port throttle body and intake manifold might be a restriction as well. I would try to source a different intake and T/B. +1, I would LOVE a pair of those twin plate TBs though..... Those things are TINY, ESPECIALLY when you stick ONE on a 3.1 liter turbocharged car!!!!! Change that and your exhaust and I bet you get a MEGA big jump in power and torque, and in how quickly they come on, as son as you get it tuned. You have gone and built yourself a VERY rare thing... a car that actually CAN gain alot of power just by opening the intake and outlet a good bit! Most of us start there with otherwise stock engines and hope for real gains, think we get real gains, but really just get butt-dyno horsepower. Quote Link to comment Share on other sites More sharing options...
Kash Posted March 19, 2009 Share Posted March 19, 2009 I'm running a Turbonetics T3/T04E 50 trim ar60 compressor (stage 3 turbine wheel w/ internal wastegate)...and a 3 inch exhaust. Base timeing is aprox 17.5 deg...will be bumping up the timing to 20 deg and push boost to 18 psi when engine is all broken in...looking for about 350hp at the wheel...current A/F ratio is at about 11.5 under boost. Quote Link to comment Share on other sites More sharing options...
Kash Posted March 19, 2009 Share Posted March 19, 2009 Here she is: Quote Link to comment Share on other sites More sharing options...
Daeron Posted March 19, 2009 Share Posted March 19, 2009 Another question I had.. You said L20ET rods were used. I jumped over to the OZDat calculator and all I could find were L20A rods (6-cyl) at 128 mm which set the pistons listed at -4mm deck height and about 6.5:1 compression, or maybe Z20/L20B rods which were WAY too tall. Did the L20ET have different rods/stroke from the NA L20A? Quote Link to comment Share on other sites More sharing options...
djz Posted March 19, 2009 Author Share Posted March 19, 2009 L20ET rods are the same length as L24 rods and have 9mm bolts. The throttlebody is small, its not as easy to adapt a new throttlebody onto my manifold due to the shape on the flange for the dual butterfly tb. I'll be making a new inlet manifold as soon as I get time. I did just discover this as I was cutting the 2.5" exhaust off, can't have been helping much. It's the inside of the hotdog muffler I had in the middle. Bit of a pity, the exhaust is only 3 or 4 years old. Quote Link to comment Share on other sites More sharing options...
Daeron Posted March 19, 2009 Share Posted March 19, 2009 every L-series intake manifold has the oval-shaped hole in the flange for the TB, even all of the USDM ones and we never got anything but single plate TBs. Our cars just have to cope with the awkward shaping from factory, and when people install the 60mm TB from the Ka they hog the hole out as much as possible to make it work. Snag a TB from a stanza or a 240SX or something, and adapt that on there (unless you are close to achieving your other intake setup you mentioned earlier in the thread.) If the large butterfly is 30mm in diameter and the small one is 20, then you have a combined cross sectional area of 1021mm^2. If they are 40/30, they are equal to a 50 mm TB with a total cross sectional area of 1963mm^2, and a 60mm TB has a cross sectional area of 2827 mm^2. I HIGHLY DOUBT its 40x30, but I have never laid eyes on one, so I obviously have no place to speak on that one... but you tell me. BTW, for reference purposes, a 2.5" exhaust (63.5 mm) has 3167mm^2 cross sectional area, and a 3" (76.2mm) has 4560mm^2 cross sectional area. Quote Link to comment Share on other sites More sharing options...
djz Posted March 19, 2009 Author Share Posted March 19, 2009 every L-series intake manifold has the oval-shaped hole in the flange for the TB, even all of the USDM ones and we never got anything but single plate TBs. Our cars just have to cope with the awkward shaping from factory, and when people install the 60mm TB from the Ka they hog the hole out as much as possible to make it work. Snag a TB from a stanza or a 240SX or something, and adapt that on there (unless you are close to achieving your other intake setup you mentioned earlier in the thread.) Hey, yeah I don't think that is going to work, here is a picture of a flange like mine next to an SR20 throttlebody flange which is ths same bolt pattern as the KA and RB ones. Quote Link to comment Share on other sites More sharing options...
stagefumer11 Posted March 19, 2009 Share Posted March 19, 2009 From what ive seen here in NZ the only L serries intake manifold you can stick a ka/Sr/ca Throttle body on is a L20et intake.. I did the same swap myself.. Deffinitly not the intake you'd want to run on that 3.1L either way. Runners are to small.. Maybe going to a intake like im running ? Quote Link to comment Share on other sites More sharing options...
djz Posted March 19, 2009 Author Share Posted March 19, 2009 Hey man, thats the plan at the moment, I've got that spare manifold I took the photo off to cut the head flange/injector mounts off and I've got a new throttlebody, just have to get around to milling out the plate the runners will be welded on to and getting a plenum made up. I'd just much rather be driving it that having it in pieces all the time, I only get to drive it on the weekend as it is. It's probably only got another 1 or 2 WOFs left before they start failing it on rust around the windscreen and in the roof. Quote Link to comment Share on other sites More sharing options...
stagefumer11 Posted March 19, 2009 Share Posted March 19, 2009 Hey man, thats the plan at the moment, I've got that spare manifold I took the photo off to cut the head flange/injector mounts off and I've got a new throttlebody, just have to get around to milling out the plate the runners will be welded on to and getting a plenum made up. I'd just much rather be driving it that having it in pieces all the time, I only get to drive it on the weekend as it is. It's probably only got another 1 or 2 WOFs left before they start failing it on rust around the windscreen and in the roof. , I know how you feel.. Mine's been off the road for 3 years now.. Jack of funds dont help.. I got half of the plenum made buy rips.. And buy the name it wasnt cheep.. It was modified again to fit the velocity stacks, Installing them upset the flow.. As you can see its been widend.., Thank god for a good brother in law. Have you got someone to weld one up for you ? Quote Link to comment Share on other sites More sharing options...
Chris240zTurbo Posted March 19, 2009 Share Posted March 19, 2009 (edited) Wow, that exhaust is not good, after seeing the resonator in that muffler all dislodged and pinched down like that, I'm a bit surprised it made the power it did! that is one serious cork in the air flow! a new 3" exhaust will do wonders! Getting a regular single blade T/B intake in the U.S. is not a problem, as well as a 60mm T/B. Myself or someone else here could pick you one up, but I'd imagine shipping would be out of sight. Building up an intake from scratch with larger runners and plenum would be best, but surely a USDM intake would be better than what you're running now, just a thought. edit: get at least a screamer pipe on that wastegate discharge before you give yourself brain damage, I'm pretty sure that's what's wrong with me, DATSUN FUMES!!! Edited March 19, 2009 by Chris240zTurbo brain damage Quote Link to comment Share on other sites More sharing options...
Bernardd Posted March 19, 2009 Share Posted March 19, 2009 L20ET rods are the same length as L24 rods and have 9mm bolts. The throttlebody is small, its not as easy to adapt a new throttlebody onto my manifold due to the shape on the flange for the dual butterfly tb. I'll be making a new inlet manifold as soon as I get time. I did just discover this as I was cutting the 2.5" exhaust off, can't have been helping much. It's the inside of the hotdog muffler I had in the middle. Bit of a pity, the exhaust is only 3 or 4 years old. That's exactly what happened to the muffler on my car. Quote Link to comment Share on other sites More sharing options...
stagefumer11 Posted March 23, 2009 Share Posted March 23, 2009 Any progress ? Quote Link to comment Share on other sites More sharing options...
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