Guest Anonymous Posted April 12, 2002 Share Posted April 12, 2002 I was curious as to when you guys get full boost by. My car doesnt develop full boost until 3800 rpms. i have a t3/TO4E w/ a 60 trim compressor housing. I drove my friends turbo 240 w/ a smaller t3/TO4 (and haltec) and his thing develops boost no matter what rpm. You could cruise along at 45 mph in fifth gear, floor it, and the boost gauge would slowly go up. I was thinking it could be a problem with my stock FI system. It seems at low rpm, it doesnt matter how much gas i give it, it reacts the same way. Just feels like i have major turbo lag. Once i spool up, it runs great. But i have so much lag, by the time i spool up i am out of revs. Driving around the city is also hard, because i have to basically floor it off the line, all the time. like i said, there seems to be no difference at 1/4 throttle and 3/4 throttle. I do have a leaking injector i believe(wont hold fuel pressure at fuel rail, goes down to 0 in about 20 mins after shutting car off). I dont have an EGR or vccm, which i took off, but shouldnt affect the drivability of the car. Any ideas on to what my problem is? I wish i could figure it out, it would make driving my car alot more fun. Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted April 12, 2002 Share Posted April 12, 2002 Also, are you sure your wastegate actuator doesn't have the wastegate open partially? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 13, 2002 Share Posted April 13, 2002 I replaced the injectors and still the same problem. I will have to check the wastegate. That could be something withi t. It seems my turbo is REALLY loud, like psssssssh(get that? ). Could having a restricted exhaust e a problem? Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted April 13, 2002 Share Posted April 13, 2002 Is there a leak in the intake system? Is the blow off valve stuck open? These could be forcing the mass air flow sensor to be sending wrong numbers because it thinks more air is flowing to the engine when in reality it's leaking out. I would think this isn't the case, because I imagine you would have heard a leak by now, but maybe...just maybe... DJSS Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 13, 2002 Share Posted April 13, 2002 Well i spent all day trouble shooting this problem to no avail. First i looked for any leaks, but couldnt find any. I even put in a Good pcv valve, then tried welding my old one shut and puttin that in. NO difference either way. I even played around with the timing and afm spring with no luck there. one thing i tried is that i wired the wastegate close. I still started building boost around 3200. The boost came on quicker but i didn't stay on the throttle, I dont like my boost spiking to 20+psi. NO luck there, and i CANT find any leaks anywhere. I wish i could figure this out, or wish i wouldnt have driven a turbo car and realized how mine is SUPPOSE to be running Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted April 13, 2002 Share Posted April 13, 2002 I'm not a turbo specialist by any stretch of the imagination, but I'll take a guess anyway. The 60 trim compressor sounds large for the application. I know that I was recommended a 60 trim T3 for a twin turbo V8 application. Perhaps a 42 or 48 trim could liven things up a bit. As for a different problem making it seem like the turbo is at fault, I can see that happening. If you had a leaky injector, or one that is stuck partially or fully open at all times, then at anything less than WOT, there is too much to WAYYY too much fuel entering the engine. Grab a bottle of STP fuel injector cleaner from O'Reilly and put it in the tank when you have 1/4 tank of gas left. If it works, you'll notice the difference in less than 2 miles. If the problem subsides and then reoccurs, you can blame it on a fuel injector problem, and may look into replacing some or all of the injectors. DJSS Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted April 13, 2002 Share Posted April 13, 2002 A restricted exhaust affects performance, yes. To a very, very small amount relative to the problems you're having. It would take a POTATO in the exhaust to affect it that much, but since the car can get to 3800+ rpm, we know that isn't the case. I highly doubt the turbo is malfunctioning, because a broken blade or something of the sorts would be loud, and everything would be off balance. At a 20psi surge like you mentioned, an off-balance turbo would be obvious. I'm kindof at a loss here, as turbos aren't really my thing. My dad has a turbo Z, but we have had other problems than this to deal with, and it's not even road worthy yet. Sorry, but good luck in fixing that setup DJSS Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 13, 2002 Share Posted April 13, 2002 Where in Texas are you? The lack of a haltech and turbo size is probably most of your problem. The 60 series turbo is pretty big for a stock motor, especially if you have stock exhaust. I'd be interested in taking a look at the car for you if you happen to be in the DFW area. Scottie can vouch for my expertise. Greg www.zdriver.com/members/greg Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 13, 2002 Share Posted April 13, 2002 I am on the northside of houston, by Lake Conroe. I know there's quite a few DFW area guys, maybe we can arrange to meet somewhere? Quote Link to comment Share on other sites More sharing options...
240Z Turbo Posted April 16, 2002 Share Posted April 16, 2002 ZF, you have some issues that may be affecting spoolup. 1st off, just because it takes longer to reach full boost does not mean that you are not making more power at part boost than you were with the smaller turbo. HUH? Anyway, my 60-1 reached full boost about 4300rpm and TimZ's T64 is in the 4300rpm range as well. Who sized up the turbine side of that turbo? It could be that you need a smaller A/R on the hot side which will allow you to spool up faster. Can you give us the A/R for the turbine housing. BTW, what is a 60-trim compressor housing? Do you mean 60-trim compressor wheel? Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted April 16, 2002 Share Posted April 16, 2002 Greg? Greg Who? He don't know diddly How ya been? Where ya been? How's the stageII? Regarding the spoolup problem, there probably is something wrong there but 240Z Turbo makes a good point, i.e., do not compare the "feel" of the hybrid to the feel of the stock T3. I had all kinds of problems launching with the stock T3 but it sre felt snappy. I switched to a hybrid and the first reaction was that it felt "soft" but I dropped .35-sec of my 60' first time out. It was making a lot more power. You could cruise along at 45 mph in fifth gear, floor it, and the boost gauge would slowly go up No surprise there. DOWNSHIFT. Like some of the other guys said, the obvious things to check for are running too rich at the bottom-end, wastegate puck not sealing shut, exhaust leak BEFORE the turbo, timing way off. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 16, 2002 Share Posted April 16, 2002 the turbo is a garrett air research T04/T3 hybrid turbo w/a water cooled center section. the first time i had it built, kevin at majestic in waco, tweaked it with (i think) "T" trim wheels, stock sized on the exhaust side, and 34mm on the blower side. the blower side had/has either a .60 or .62 A/R. now housing a 32mm wheel. kevin also installed a 12deg clipped wheel on the exhaust side. I got that from the guy i got it from. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted April 17, 2002 Share Posted April 17, 2002 The clipped wheel I have heard contributes to a slower spoolup - I believe it is a turbine mod to increase exhaust flow without moving to a larger turbine housing. You may just not have the flow to get that compressor pressurized before you run out of revs, but it wouldn't surprise me if you were actually making more power than before (like Scottie said). Then again, if you are too rich or timing is off, the motor will feel like a slug. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 18, 2002 Share Posted April 18, 2002 ....not sure...but this makes me a little uneasy... ..i just had a turbo made for my 82zxt ,i dont know much about them,i'm just relying on the guy's judgement... he says it ought to spool very fast....its a T-3/4CA TO4B....(whatever that is)....he says its got a stage3 on one side and the trim is 57?...its watercooled and has better bearings...than most...etc..(he runs or owns the turbo auto here in nashville)...is this the turbo you have?...anybody know anything about these?...i supposed to pick it up tomorrow...s Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 20, 2002 Share Posted April 20, 2002 i have a 60 trim t3-to4e with .5 ar comp and .63 ar exh with 11 degree clip on stock exh wheel and it spools really fast once you hit about 2500 its on, may want to check your comp. pressure on all 6 low reading on a few cylinders can cause lag Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted April 20, 2002 Share Posted April 20, 2002 Scott, Clipping in my opinion is almost a waste of time. For a street car, I want no clip at all. The spool will suffer, especially with a 12degree clip (which is pretty big, most I'd ever go with is a 10degree...but then again...I'm anti clip man! =o) Is your wastegate internal? I've seen alot of turbos suffer from cracked turbine housings, which would cause slow spool up. Quote Link to comment Share on other sites More sharing options...
Guest the_dj Posted April 20, 2002 Share Posted April 20, 2002 You have to remember that "your friend's 240Z" is making 330rwhp! Lol! I just realized that you were the one making this post. I'll take a look when I see you while I'm in town, maybe meet up on the 5th of May. DJSS Quote Link to comment Share on other sites More sharing options...
awd92gsx Posted April 22, 2002 Share Posted April 22, 2002 I meant to ask this before...but...Scott...what's your base timing set at? Quote Link to comment Share on other sites More sharing options...
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