Guest Jason84NA-T Posted June 22, 2004 Share Posted June 22, 2004 Picking out the upgrade to my stock T3 which I am pushing the living piss out of right now. Debating between 57 trim and 60 trim, this turbo: http://store.yahoo.com/cheapturbo/gart3to457tr1.html I am planning on using the stock exhaust housing and O2 elbow, boring the wastegate hole slightly larger, etc. Question is: To swap the stock exhaust housing (so I can use the O2 elbow and DP) onto this new turbo, I will probably need to have my stock exhaust housing bored out to fit this new stage 3 turbine, correct? or is the bore the same? Anything I am missing here? Ok, most of you probably don't know me. I normally post on Z31.com but recently have become more and more fed up with some of the idiots on there (which, still, in NO way compare to the complete morons on Zcar.com) not that I am bashing, but rather I am just feeling the water over here. my web site: http://www.redz31.com If you are interested in seeing my modifications click this link: http://z31.com/board/print_profile.php3?user_id=38107 Thanks! Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted June 23, 2004 Share Posted June 23, 2004 Hi Jason - Yes you are correct, the exhaust housing will need to be reworked to fit the stage 3 wheel. If you are going to a 57 or 60 trim wheel with a TO4E cover, I would caution you about going with the Stg 3 turbine. I have a TO4E60/T3 stage 3 .63 exhaust and I have boost creep problems. I ported the WG housing (ford style) to 1.25" with a 1.5" flapper - that is the biggest that will go in there - now the boost creep is managable but I think that I'm limiting my topend power with the exhaust side. I have a .82 stage 3 housing on order, just to see if it helps out. It isn't a major expense ($140). I would recommend going to a stg 5 wheel right off the bat. If I was getting another big hybrid turbo, I would go that way or to a T4 turbine (P trim). Just my $0.02 Doug Quote Link to comment Share on other sites More sharing options...
Kennysgreen280zt Posted June 23, 2004 Share Posted June 23, 2004 Goin a little offtopic here: Doug, how much HP does your car make? Quote Link to comment Share on other sites More sharing options...
Guest Jason84NA-T Posted June 23, 2004 Share Posted June 23, 2004 P trim T4 was an idea I was considering, but if I was going that route I would just spend the little pile of extra money and go with ext. wastegate/ custom DP... My primary concern right now is not having to have a downpipe w/ o2 bung made, I would like to use the stock housing for this reason, I already have a very nice 3" downpipe anyway. Do you still have boost creep problems even with the ported hole and larger flapper? I am planning on 16ish PSI on stock fuel (running 15 now and maxing out the T3) with the pressure cranked as it is currently to 45PSI base. I was amazed at how much more boost I could run on pump gas with the pressure increased, sure it runs a bit rich at low boost but once it hits 15PSI it feels really nice. I can only imagine it with a more efficient turbo. Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted June 23, 2004 Share Posted June 23, 2004 Jason - I still have boost creep problems - but they are manageable now. It will hold 15psi till about 5.5K and then it starts to climb. 17-18 psi at 6.5K. I usually shift there as there is lots of TQ down lower. 15 psi will feel a lot different with a bigger compressor. I don't believe that you will get away with that high of boost without a lot more fuel. The air density will be a lot higher with a more efficient compressor at work. I would rather have the airflow through the turbine section than through the WG hole - that is why I'm going to try the .82 housing. I would like move the boost threshold up to around 3K on my engine, also. Kenny - I honestly have no idea - sorry - never had it on a dyno. Its a freshened stock bottom end with a P90A. Mild home port/polish/unshroud. 60mmTB,550 cc injectors. I would suspect that it runs mid 300's average from 4-6K. That's what I get from the HP calcs. It runs consistant 12.7 @ 113-115 on 225/45/17 street rubber, right off of the street. It ran 12.2 @116 on Hoosier QTP's on pump gas - but with no D/S hoop, the track gives me grief when I run slicks. I have run 250+ passes with the car - from 13.7@102 after the turbo conversion to 12.2@116 now. I gave up on the stock turbo at 12.9. I hot-lapped 25 passes one night, on the stock turbo - it is still alive in another Z! Quote Link to comment Share on other sites More sharing options...
Pyro Posted June 23, 2004 Share Posted June 23, 2004 Jason, You should get a Bell Enginerring FMU. It only adds fuel pressure under boost. It also ramps up fuel pressure at a ratio you set, 1:1 to 1:10. Goes for 200.00. I use one on my 76 turbo and it gets me by using all the stock 76 efi by ramping up to 75 psi of fuel pressure at 12 psi of boost. I'm sure it would work much better in your situation. Should prevent running rich during normal driving. Quote Link to comment Share on other sites More sharing options...
Guest Jason84NA-T Posted June 24, 2004 Share Posted June 24, 2004 Doug- Thanks for the advice. I guess I'll just have to see what I can do with it, if I run into boost creep that I can't manage or that sends me over the detonation threshold I guess I will have to go external. I really want to see what I can make it do with the stock injectors/ecu... which leads me to: Pyro- Thanks for the advice, I considered them for a while... crushing the stock regulator was a quick fix for now. I was looking at rising rate FPR's but none of them were adjustable rate of rise (thus making them no better than a crushed stock FPR), guess FMU is the way to go. hmmmmm, If you could check my reasoning here, I am still somewhat new at this... at a 1:2 rate of rise 15PSI boost would yield 30PSI fuel pressure increase from the stock base of 37ish... this would yield an additional 15PSI of fuel pressure when under boost (subtracting manifold pressure for absolute), meaning a "true" fuel pressure of 52PSI compared to 37 stock. This is 1.4 times as much fuel "in theory". Since the stock 260cc injectors max out around 275-280HP or 12.5PSI: 12.5/37=x/52 x=17.57 So, If I am correct, this would mean (in theory) the stock fuel injectors would put out enough fuel to support about 17PSI? Sure, the ECU and AFM will still hinder perfromance at those pressures, but I can handle that. Thanks. Quote Link to comment Share on other sites More sharing options...
Pyro Posted June 24, 2004 Share Posted June 24, 2004 YES, but not quite. The formula for increased flow after more pressure is: The square root of (new pressure/old pressure) then muiltplied by the old flow rate. Check out the RC Engineering web site. so the sqaure root of (60psi/37psi) is 1.2734 and 1.2734 x 260= 331cc 330 cc is good for 330 hp with a 6 cylinder. 80 psi would make 382cc injectors out of your 260cc. (382hp potenial) However, after 60 psi another fuel pump would most likely be required. Quote Link to comment Share on other sites More sharing options...
Guest Jason84NA-T Posted June 25, 2004 Share Posted June 25, 2004 However' date=' after 60 psi another fuel pump would most likely be required.[/quote'] Another, as in an additional pump? I already have a walbro I installed a while ago, I don't think I'll run into flow issues with it until well over 500HP. By then I will have to go to larger fuel lines anyway. Essentially, I should be able to get almost 300HP to the wheels with the stock fuel system and the new turbo. By then my AFM will easily be maxed out, or so I would think. Another silly question though, again I am relatively new to tuning turbo cars. If I were to install a set of SVO injectors, could I just decrease the base fuel pressure accordingly to account for the larger flow (since the duty cycle for the 260's will be given from the stock ECU) and adjust accordingly for boost? Using the same 60PSI fuel pressure on those injectors would yield almost 500hp worth of fuel... Quote Link to comment Share on other sites More sharing options...
Pyro Posted June 25, 2004 Share Posted June 25, 2004 Well, you can try using one pump. The problem is, the higher the pressure the lower the flow. For example, a pump that can put out 250 gph at 40 psi might only be able to pump 100 gph at 80 psi. This can become a problem when the fuel ratio is controlled by increasing fuel pressure. It would be a good idea to install a fuel pressure gauge if you use an FMU so you can monitor the fuel pressure. If a single pump can't hold the pressure during high load conditions then a helper pump should be used. I use two stock pumps in series (one pump feeds the other) to supply fuel to my FMU. One pump could only manage 50 psi during long 3rd gear runs. Two stock pumps can hold 75 or 80 psi. I'm not 100% sure but I think at 80 psi, both pumps think they are pumping 40 psi each. Reducing the pressure to the injectors might not be a good idea. Low pressure will mess up the spray pattern. You might be able to find the spec for the min pressure requirement for those injectors. Quote Link to comment Share on other sites More sharing options...
Guest Jason84NA-T Posted June 27, 2004 Share Posted June 27, 2004 I already have a fuel pressure gauge installed, and the stock regulator crushed to provide 40PSI idle base pressure, it does run rich under low boost but I think the FMU will fix that. We'll see where the walbro can go... people with 450RWHP Z31's on JWT setups still use the simgle walbro at 50-60PSI fuel pressure. I'm thinking it'll be fine. We'll see what I can put down once I have tuned it on the dyno at the end of the summer. Quote Link to comment Share on other sites More sharing options...
Clifton Posted June 29, 2004 Share Posted June 29, 2004 Depending on how much boost you plan to run I would either get the T4 E60 Or preferably the 60-1 if you are going to be running over 15 PSI. Compare the flow maps. The E 60 only flows 50 lbs. The 60-1 will still be in the 70% area at 50lbs. Quote Link to comment Share on other sites More sharing options...
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