evildky Posted November 28, 2004 Share Posted November 28, 2004 so how much boost and a flattop p90 combo handle? with stock internals of course, I am oputting one of these together and have been feeling a lille worried about popping it, can it handle 10psi with intercooling or can it take even more than that ? I am hoping to get thsi thing up to 350-400rwhp will that combo hold up to it? Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 28, 2004 Share Posted November 28, 2004 Bastaad, have you verified your timing on the camshaft? If it's installed advanced or retarded it can have a DRASTIC effect on the way an engine performs. The graph still crosses at 5252 rpm, the dyno guy sounds a bit hokey... But I agree, the stock camshaft shouldn't limit you at all. You may have something with your exhaust theory, a restrictive downpipe, crushbent elbows, etc etc etc all result in impediments to flow. I have an experiment for ya: pull off you dwonpipe, and bolt a deflector baffle to it, and dyno like that. Not only would it sound evil, it should answer your questions on pipe sizing nicely. remember JeffP saw some good numbers returned with just his 3" downpipe when used on a stock engine. Flow helps turbos! In japan it was not uncommon in the 80's to see turbo cars with freakin' sewerpipes for the turbos. I mean 100 and 125mm piping from a twin turbo setup. You guys think packaging 3" is difficult! Try 4! And bigger! Quote Link to comment Share on other sites More sharing options...
Sean73 Posted November 28, 2004 Share Posted November 28, 2004 I run a F54/P90 combo with flattops (8.8:1 CR) T3/T04E Turbo NPR IC 3" mandrel exhaust / 2.5" custom DP Z31 ECCS 5 speed, RPS clutch, 3.7 R200 I am currently running 10 psi, and the acceleration is insane. I light up the 225s easily, and 1st through 3rd gear is just a blur. So far so good, with about 700 miles on the rebuilt motor. I am going to the dyno before I turn up the boost any further though. Sean Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 29, 2004 Share Posted November 29, 2004 I checked the cam timing ages ago... I THINK it was on the #1 position but now I'm not sure. The #2 and #3 positions move the power band lower in the RPM range right? The numbers definately did NOT cross at 5252rpm on the dynapack dyno. That's why I didn't go back there the last time I dynoed. It just didn't make any sense, and the shop owner could not explain it... as I said... he didn't even see the logic behind what I was saying when I tried to explain it to him, and was getting impatient with me, so I was like screw you dude...... I won't be able to try your experiment... not going back to the dyno any time soon if at all, once I get my own WB O2 I dont' really see a point in going any more. I know I'm going to go with a full 3" exhaust whether it moves the power band up or not... I know there is power to be gained there either way, or rather, I'm after the improved turbo response and a better sound. I'm still running the stock downpipe but again I've seen guys dyno with that and have power peak where it's supposed to, 5000-5500rpm. I'll make it a point to check into the cam timing again... I need to readjust the valves soon anyways. I'm curious though, what exactly would I use as a deflector baffle to run with just the open downpipe? Quote Link to comment Share on other sites More sharing options...
rags Posted November 29, 2004 Share Posted November 29, 2004 By any chance were there 2 different graps for HP and torque? If there were, that would explain why the two didn't intersect at 5252. Joe Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted November 30, 2004 Share Posted November 30, 2004 the graphs were seperate, they did not overlay each other on one sheet/screen, but anyways I wasn't look at the line, I was actually looking at the number. I looked at the torque at several different specific rpms, and plugged it into that equation (torque x rpm / 5252 = hp) and then compared to what the hp graph showed at those same rpm and it was way off. Also, the numbers were not the same at 5252rpm on each graph. Quote Link to comment Share on other sites More sharing options...
TimZ Posted November 30, 2004 Share Posted November 30, 2004 What's the chances of this: Heres' James T's Twin Turbo Dyno chart he just posted over at ZC.C on aonther topic.Please note peak torque and when it occurs: This would tend to make the clutch very unhappy' date=' especially if you have on that is dependent on flyweights to clamp it down at higher rpms... 8) But uncannily it's near 4200, right at the magic peak point for most of the other units. The graphs should cross at 5252rpm. If they dont, or peak HP occurs before that point, something is wrong in fueling or camshaft selection![/quote'] James was running a PowerGlide on that run as I recall, so no clutch. You all realize that he's got that engine up for sale, right? http://hybridz.org/phpbb2/viewtopic.php?t=38706 Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted December 1, 2004 Share Posted December 1, 2004 hey guys... so... cam timing? The lower the number position you set it to, the higher in the rpm range the torque will peak, yes? Or do I have it opposite? Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted December 1, 2004 Share Posted December 1, 2004 well guys quick question.. right now my L28ET in my blue Z is at the machine shop.. it needs pistions, so should i go with flat top stockers or turbo stockers? running like 12psi and will end up at like 16psi. mike Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted December 1, 2004 Share Posted December 1, 2004 On3go - If it were me, and I were in a situation where I would be running anything other than bone stock EFI, i.e., I had a way to supply a lot of extra fuel and to retard ignition timing... I'd definately go with flat tops and reap the benefits. Quote Link to comment Share on other sites More sharing options...
Guest ON3GO Posted December 1, 2004 Share Posted December 1, 2004 well heres my situation.. i dont have mad cash at the moment. just bought a full FMIC system with piping for the blue Z, bought all new gaskets, water pump, water temp gauge (dont wanna overheat again, stock gauge sucks!!) but still suck with my damn 77 280z ecu and harness. I have that MSD 6-BTM unit and a 79 280z dizzy but the electronic part is messed up (need that if i stay with this MSD unit).. i really wanna do a MSnS but i dunno, dont have much time. wish had the money for like a haltech or microtech for this car. i just want this damn car running perfect! and this damn ecu isnt cutting it, on boost it runs great but im getting like 10mpg for christ sakes.. mike Quote Link to comment Share on other sites More sharing options...
Guest bastaad525 Posted December 1, 2004 Share Posted December 1, 2004 ehhh... now I dunno if I'd want to run the N/A dizzy and ECU with flat tops on a turbo motor or ANY turbo motor... but then again.. not only can you use the BTM to retard the timing under boost, you can also recurve the dizzy... it's actually a very easy process curving to give less total advance. And you already have fuel covered right? don't you already have 370's AND an RRFPR? With all that I don't see why you couldn't run flattops even on a stock N/A ECU. You'll always have the ability to upgrade later, whereas... I would hope you only ever need to rebuild that motor once so if you've got the chance, I say go with the flattops... everyone who's done so has been more than happy with their motors and I dont think I've heard anyone have any regrets for doing it. Even if it means you have to take it easy until you sort out the EFI at some later time, at least you'll have that part covered when you're ready to go. Quote Link to comment Share on other sites More sharing options...
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