Jwink25 Posted February 11, 2003 Share Posted February 11, 2003 I have a few questions I am hoping you turbo guys can shed some light on. I will be upgrading my stock turbo to a T04B. This gives me more air at lower boost levels...right? By doing this will I have to add more fuel? The engine is all stock except for the following... 1. The head will be gasket matched to the intake and exhaust and the bowls in the head will be smoothed. 2. I'll build a 3" downpipe and run a 3" exhaust all the wat to the back. 3. I'll be looking for an innercooler but may not run one at first. I am using the stock turbo wiring and ECU. What are my options to adding more fuel without it running like crap at idle or part throttle? Will a raising rate fuel regulator work? Or, can I just add slightly larger injectors? What are some of the things you guys did. I have seen alot of info about different people running different stuff...but most of it has been on cars with aftermarket engine management sys. Any thoughts or ideas? Thanks guys. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted February 11, 2003 Share Posted February 11, 2003 Just throw the turbo on. The AFM will measure all the air going into the engine, and will fuel it appropriately. Only time you have to worry about fuel issues is when your boost gets much higher or you change injector sizes. Quote Link to comment Share on other sites More sharing options...
Jwink25 Posted February 11, 2003 Author Share Posted February 11, 2003 How much boost can I run without having to worry about fuel? I would like to see at least 250HP at the crank...maybe more. With an innercooler and say 12 psi could I see that? Would fuel be an issue then? Thanks! Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted February 11, 2003 Share Posted February 11, 2003 When you think about fuel for a turbo setup, you have to think of it as a "system" that includes pump, filter, lines, FPR and injectors. As you increase power, all (except maybe the lines to a point) will be affected. If you are doing it in steps, like say add the turbo w/o the I/C, here is something you can do to get a little extra fuel for that increase. - Get an adjustable FPR (you will eventually need one) and raise the fuel pressure a little to get more flow out of the stock injs. be aware that this might cause a little richness at low speeds also. - "hot-wire" the pump. Voltage has a huge effect on the efficiency of the pump and I can gaurantee the stock wiring is not supplying enough voltage. Wire the pump with 10-gauge wires from the alt or batt and run them through a relay, then use the original hot wire to trigger the relay. At WOT the pump will have more voltage and flow more. I am not advocating these are "upgrades". These are things you should be doing regardless but will get you a little more out of the stock components. Be aware that if you are currently running say 9psi with the stock turbo, 9psi with the bigger turbo is a BIG difference. Start with a lower boost level and work your way up. Make sure you have a proper, accurate boost gauge and at a minimum, an A/F meter to monitor the mixture, but an EGT gauge would be better. Run the highest grade gas you can get/afford. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted February 11, 2003 Share Posted February 11, 2003 Originally posted by Jwink25:How much boost can I run without having to worry about fuel? I would like to see at least 250HP at the crank...maybe more. With an innercooler and say 12 psi could I see that? Would fuel be an issue then? Thanks! I am running the stock fuel system with 250hp to the wheels (stock fuel injectors, stock FPR, Bosch fuel pump). I am running the Z31 ECU, and I'm not sure if it can drive the injectors more effectively than the stock 280ZXT ECU. I am fairly sure I'm starting to lean out at the top end, as I see EGTs getting to 1600F or so. I consider 250rwhp the safe maximum out of the stock fuel system (without resorting to band-aid fixes like RRFPRs and such). You can achieve this power level with a hybrid turbo and intercooler, like I have, at 12psi sea level (I run 14psi, but I'm at 5800' elevation). Quote Link to comment Share on other sites More sharing options...
Jwink25 Posted February 11, 2003 Author Share Posted February 11, 2003 Thanks for this great info guys. Where can I get a good A/F gauge that doesn't cost an arm and a leg? Quote Link to comment Share on other sites More sharing options...
yo2001 Posted February 11, 2003 Share Posted February 11, 2003 208RWHP, my A/F ratio was at 14.5:1. I'm ogin to try to hard wire the fuel pump. Quote Link to comment Share on other sites More sharing options...
Mudge Posted February 11, 2003 Share Posted February 11, 2003 Some people use EGTs, but I dont know hardly a thing about them. With that, a wideband is going to cost you around $300+ depending on options. If you compare it to hours and hours of dyno time though, it could save you money, especially if you use it on more than one car. Only thing is going WOT in fourth gear on the street isn't going to be all that legal... Quote Link to comment Share on other sites More sharing options...
DAW Posted February 11, 2003 Share Posted February 11, 2003 I would recommend a rising rate fpr as you don't trade off low speed driveability problems as with larger injectors. This is a plausable performance mod within the hp range you're talking about and it's good insurance. DAW Quote Link to comment Share on other sites More sharing options...
Guest Zcarsmakemyheadhurt Posted February 21, 2003 Share Posted February 21, 2003 Man oh man, lots of ways to answer this question. First off most people go with stand alone because the factory fuel computer can not be "worked" to use large injectors. Once you put a big set of injectors on you cannot modifiy the injector time to slow down for the much higher flow rate of a large injector. Now I know people will not agree and say that it can be done with tricks, but from what I have seen these tricks make your car drive like crap off boost. I spending the money on a standalone is not in you plan you can run a FMU, with a hi pressure fuel pump. The FMU brings up the fuel pressure only on boost. Your idle pressure is not changed and the factory regulator remains when adding a FMU to the picture. The fuel pump supplies you with the pressure to get up there. FMU's come with different ratings from 1 pound of fuel pressure per pound of boost to 12psi per pound of boost pressure. You have to do the math and figure out how much boost your going to run and how much fuel pressure is going to be needed not going over 75 pounds of fuel pressure cause you will blow out the injector. I have a nice additional injector controller that may help you out also. If you would like more info on this stuff I will be in my new office next week, Monday. Give me a call.... Alex Costa Costa Speed & Performance 305-888-3015 Quote Link to comment Share on other sites More sharing options...
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