Can it be? Yes it is! Even more dyno results!!!

[Guest bastaad525]

My stack of dyno graph sheets piling up here

 

So I got in at a local shop that I found today... I must say these guys were just about the coolest guys I've had the pleasure of doing business with so far... very down to earth people, no bad attitude or vibe from them, unlike every other shop I've been to thus far. And they didn't leave handprints all over my car!!!

 

Well... lets get down to the nitty gritty

 

After 6 pulls, tuning the BEGI FMU bit by bit, I ended up with:

 

226 RWHP @ 4600 RPM (hp keeps peaking at lower RPM, wtf?)

248 RWTQ @ 4200 RPM (down a bit from my last dyno session )

 

This was at 12-13psi of boost, with the FMU set to provide around 65-70psi of fuel pressure, and FINALLY running a nice safe air/fuel ratio in the range of about 11.5-12.5:1 all the way up to 6000rpm. Yes there IS a rich spike in the mid RPM, to about 10:1 A/F ratio, it's very short, only about 500rpm, before it leans back out to high 11 - low 12:1 area. BUT, for anyone who remembers my first dyno pulls on the bone stock EFI, no I/C, and no FMU, it did the EXACT SAME THING, so this is NOT the fault of the FMU. Also this was with the wideband O2 mounted in the downpipe, not a tailpipe sniffer as with every other dyno I've been on. I will say the one thing I didn't like about the FMU is that the fuel curve is not flat... the pressure was oscillating a bit, so the fuel curve is kinda jagged, BUT the peak highs and lows aren't that far apart... maybe a difference of .2 AFR. Otherwise I must say I'm VERY happy with the FMU... it works exactly as advertised and exactly how I hoped. I know a lot of guys don't agree with using it, but I believe this is a VERY nice alternative to bigger injectors, at least for me. Keep in mind the chances that I'll ever upgrade from the stock T3 turbo is slim to none, so 370cc injectors would have been overkill for me. I wanted to do as much as I could with stock EFI, injectors, and turbo, and the FMU made that possible.

 

A couple things I want to note, differences from the last dyno pull and such. For one, peak torque was way down, about 20 lb feet, while HP was up, about 15hp, but HP peaked sooner by about 500rpm, whereas torque peaked 100rpm later I now know for a 100% FACT that I would have been running way too lean the last time I dynoed... if you remember the O2 sensor was doing all kinds of crazy things at the last dyno test, and by the time we did the last pull it had stopped working completely, so we really weren't too sure about the readings it was giving. But I know for sure that it must have been at least somewhat lean either way, because during todays tests, with the FMU adjusted all the way lean (basically no increase over the stock FPR, which is all I had at the last dyno), I was up at about 14:1 AFR at about 4000rpm. It took quite a bit more adjustment on the FMU bleed screw than I had anticipated to get the desired rate of gain and AFR... I had to turn the screw in about 3 full turns from all the way out to get final fuel pressure to about 65psi... about a 2:1 rate of gain. What was odd was that the first two full turns made almost NO difference on the first two pulls... but then that third turn dropped the AFR from 14:1 to 11:1 ! After that, that little screw gets super sensitive. Anyways... I figured power might drop down a bit from richening it up, so that partially accounts for the lower torque #'s on this session. But also, one difference here is that this shop runs a Dynapack dyno, whereas I've always tested on Dynojets before now. With the Dynapack there are no rollers... they take off the rear tires and bolt some shafts up to the hubs, and then insert those into two seperate machines. The tech who was doing my pulls said he personally has a fixed up camaro, that he has had both on dynojets and on the dynapack at their shop, and has consistently seen the dynapack read about 10% lower than the dynojet. So that may also account for the much lower torque reading... if I'm losing 10% versus the dynojet baselines I've run, that would put me at right around 250hp and 270ft lbs of torque... 270ft lbs being EXACTLY what I put down at my last dyno session, but only 210hp because the torque just fell flat after 4200rpm, due to leaning out after 4000rpm.

 

Here's a scan of the old/last dyno graph again:

 

 

 

With the right AFR above 4000rpm the shop owner there was betting on 240ish rwhp on that dyno. Also, for what little it's worth, here in the valley we're at about 500 or 800ft elevation, whereas the last dyno was at about 100ft above sea level. I want to get back on a Dynojet now... need that 'big' # for my ego

 

So... not bad not bad at all As usual, I'll post scans of the NEW graphs as soon as I get a chance.

[fl327]

What was the fuel pressure at when you had the more ideal WOT af mixture? Your dyno #s sound very familiar...

[Guest bastaad525]

Okay got the new graphs from today's tests scanned:

 

 

 

That was the second to last run, running an average of 12:1 air/fuel ratio, unfortunately unlike the dynojet graphs, on this one you can only print out 2 out of the 3 pertinent graphs, the 3 being HP, torque and air/fuel... wish I could get all three on one page

 

And this one:

 

 

All my runs compiled on one sheet, but showing ONLY torque and air/fuel curve As you can see I started out a bit lean on the first pulls, getting up to 13.6:1 or so by 4200rpm, but torque was way up as well, at about 260lb feet, and only got lower from there as I richened it up. You can also see that every single one still has that super rich dip in the midrange... again... this was occuring even before I installed the FMU... and I've seen this on every other turbo setup I've seen dynoed running the factory '81-83 EFI... it's just what they do. And you can see that the fuel curve is otherwise kinda erratic... well it seems to be divided into four different 'stages' on each run. The pre boost area, which ran at about 12:1 on each run, the just-coming-on-boost area, the rich dip, where it gets down in the 10:1 range, the first full boost area, which ran from 13.5:1 to 11.5:1 as I turned up the FMU pressure, and then a little rich dip every time at about 4800, and then back lean again, with peaks ranging from 13.5:1 to 12.7:1 by about 6000rpm. Odd... consistently unconsistent.

 

You can see that the MSD pump is holding up just fine as well... seems to do fine with flow and maintaining pressure, all the way up to 6000rpm, 70psi of fuel pressure, you can see it's still flowing enough. I know some guys say they aren't the best pumps, but it's enough for me.

 

 

Well... there you have it... and I am DONNNNNE upgrading for a while

[Guest bastaad525]

fl327 - the best mixture was achieved at right around 65psi of fuel pressure at WOT/full boost, as all of Sean73's math said it should It was hard to get a final for sure number because the fuel pressure was bouncing around a little bit at higher RPM... fluctuating between about 65-70psi. 70psi was dipping the a/f ration into the high 11:1 range.

[Guest bastaad525]

Actually I just realized... the fuel curve isn't that bad or erratic at all... it seems much more so because the graph is much taller, by comparison, with my previous dynojet graphs, where the AFR was compressed to one little 1" high section at the bottom, that 1" covering a range of from 10:1 up to 18:1, whereas this graph, from 10:1 to 13:1 takes up half the page. I took the pic into photoshop and compressed it down and it looks much much better... I'd post it but I'm apparently out of room to post pics in the HybridZ photo albums... but most of my pics were in the general area, and the photo album search feature appears to be down so I can't even find them to delete them.

[Guest bastaad525]

LOL am I overdoing it with the dyno results?? Always my favorite threads to post... and usually you guys leave a lot more than just one reply

 

Well what can I say, I wouldn't be dynoing so much if it weren't for you guys!! So much great info here I just want to contribute as much as I can, and trying to document every step of my turbo swap and upgrading like this will hopefully just add to the great knowledge base here.

[fl327]

You need to take it to the track and see what it runs.

[Guest bastaad525]

I would have done so 100x over if it was track worthy... There are a few 'issues' I need to deal with for it to pass tech... none of which had been priorities before. Unfortunately, now that I've reached my performance goal... I'm gonna be done with the Z for a while, I got stuff on my Sentra (SE-R) and one my wifes car that needs to be fixed now, and as the Sentra is now more my daily driver, I really would like to put a little money into getting some extra performance out of it as well... just a little bit to make it a little more fun.

 

Anyways... whatever I would run at the track would be a pretty bad representation of what the car can do... for one because I'm a big guy, weighing the poor girl down, and two, because I still to this day can't launch the thing worth a damn, though I try and try and try. I figure knowing the power and weight of the car I can guesstimate a good enough 1/4 time anyways... I figure it's GOTTA be good for a 13.5 or better, and 0-60 of around 5 seconds with someone who knows what their doing. A couple acceleration calculators on the 'net agree, putting the car 13.3 @ 102mph with weight set at 2700lbs (as I said, I'm a big guy). I know they aren't 100% accurate but that's a good enough estimation for me.

 

 

BTW, I don't believe what I said about the 10% loss between dynojet and dynapack is true anymore... after looking back over the test results on the dynapack, that first run running pretty lean with the FMU set to do nothing, the torque was actually really close to what I put down on the last dynojet pulls w/o the FMU, running lean... only about 10 lbft less... I figure the much lower elevation at the dynojet place, and just regular variations in different dyno's overall, probably accounts for that last 10 lbft... my final numbers on the dynapack were so much lower due to richening it up... so the final numbers are probably really close to what I'd get on a dynojet... ah well, better slower and safer than faster on the ragged edge eh? For what it's worth I probably gained a little of that back... knowing that I wasn't running lean anymore I decided to bump the ignition timing back up to stock (20* BTDC). I was running 17* before to gain some extra safety margin knowing I was probably running lean. I know the seat of the pants dyno noticed a definate improvement OFF boost... dunno if boosted power was affected really but I expect it did.

[cygnusx1]

Bast. Wow nice detective work! You have come a long way from the, "I give up!", you posted a while back. Great to see that you have reached your performance goals. I can't wait to get to a dyno and get some charts on mine. Oh, and thank the wife for us for letting you play and share your findings with us.

 

I took my Z to work this morning and got pulled over I explained that I had no idea how fast I was going due to the different trans and wheels. The speedo was probably innacurate. His radar said 52 in a 40. I was polite and he let me off the hook. It was a barren straight peice of road...I could have been doing 125mph easily but I am semi conscious about safety. This car is just tooo fast. Funny thing is that he was a young cop who had probably never seen a Z. He read it off my registration which reads DATSU. He said, "Take it easy in your datsoo!" I almost laughed.

[Guest bastaad525]

He said, "Take it easy in your datsoo!" I almost laughed.

 

 

Heheh that beats all the times I've had some kid tell me "hey nice porsche"

 

 

Yeah I'm just shy of my goal.... I think a better exhaust will take care of the rest, maybe in a few months *shrug* think I may get myself a WB O2 first, I guess I don't need to fuss with getting an rpm switch or boost controller hooked up to the FMU either.... the fuel curve now looks so similiar to the fuel curves from previous dyno's from before the FMU... you wouldn't know it was having an effect at all except I'm somehow running 12psi and pig rich

[cygnusx1]

Baast, you said you settled on 65 Psi fuel pressure at your peak boost when you last hit the dyno. Well I went out to the garage tonight and plugged in the compressor set to 15psi and set the FMU bleeder to give me 65psi in the rail. I put the 15psi pressure on the FMU and the stock regulator simultaneously then adjusted the FMU bleeder. I took it for a spin and it bogged (black smoked) like crazy under boost. If I set it to like 45psi at 15psi, it runs great under boost. Strange.....I wonder what the difference in our cars is. Any idea?

[Guest bastaad525]

That's very odd. Before I even installed the FMU, last time I dynoed, fuel pressure would get to 40psi + whatever level of boost I was running. So even when I dynoed at 10psi w/o the I/C, fuel pressure was getting up to 50psi, and still running lean above 4500rpm. From all the posts I've read here, what my car was doing was very much typical. Just about everyone here will get 40psi of fuel pressure if they unplug the vacuum reference from the FPR (0 vacuum) and then boost should add one psi of fuel pressure per 1psi of boost.

 

So I"m really baffled how you're getting 45psi max fuel pressure, at 14psi of boost and stock injectors, and not melting anything . Also, are you running the restrictor inline with the signal line to the FMU? Yo2001 and the rep over at BEGI both recommended this to me, and the car ran MUCH better after I installed it. I did have it installed when I dynoed, and still ran too rich overall, at mid 11:1's, but the car doesn't bog or smoke. I set it that rich because it would spike kinda lean at the end of the run (about 5600rpm, but then richens back up afterwards) and wanted the leanest point in the fuel curve to be 12.5:1. Kinda sux I have to run too rich just to battle a lean spike, but you wouldn't know it by driving the car.

 

Cygnus I'm still really curious, I've asked this one a couple times before, and am gonna keep asking til you tell me!!! Can you please, when you get a chance, count the number of turns you have the FMU's bleed screw turned in, from fully out? I have mine turned in three full turns.

[cygnusx1]

OK I will count the turns the way it is now. I turned it OUT one full turn tonight after I found out that the "65psi@14psi" I had set earlier today made it smoke and bog on boost. I took it for a spin after "leaning out" the FMU bleeder by one full turn and holy-moly its soooo fast.

 

-OK right now it sits at 2.5 full turns from all the way out - Runs Strong

-I had it set to 3.5 full turns from all the way out (65psi@14psi) - Too Rich

 

Yes, I remember stuffing the restrictor in the boost sense line. I will confirm but I am sure it's there.

 

 

 

So I"m really baffled how you're getting 45psi max fuel pressure, at 14psi of boost and stock injectors, and not melting anything

 

 

Yeah well I thought I explained that one. I was setting 45psi at 14psi boost by feeding the 14psi artificially to the FMU ONLY. I was NOT pressurizing the stock regulator when I was adjusting the FMU <(my bad).

 

Now I DO add pressure to BOTH and thats how I set the 65psi@14psi today.

[Guest bastaad525]

Okay maybe I'm a bit confused? So at the setting you have it at now, 2.5 turns in from fully out, with both FMU and FPR hooked up to your compressor, pushing 14psi thru both of them, then how much fuel pressure do you get?

 

 

our FMU's are set almost identically, mine is three full turns in, right in between the two points you tested. Funny thing was, on the dyno, adjusting it did almost NOTHING to the a/f ratio until 2.5 turns in. I was adjusting it one full turn at a time and the a/f only changed once I hit 3 full turns, backed it out half a turn and it leaned back almost completely to where it was when I had it set to do nothing. Any adjustment past 2.5 turns made HUGE differences though. So with the numbers you've given me before (FMU increased fuel from 40 psi at idle/0 vacuum to 45psi at full boost), and just assuming our FMU's perform more or less the same, you have it set just to the point where it's starting to affect fuel curve, and with a hybrid turbo pushing 14psi, you're probably running lean. And yeah, it will feel way faster that way... I was producing 20 ft lbs more torque at 13.6 a/f ratio, peaking almost 1000rpm sooner... always sux when you leave the dyno feeling slower than when you got there, but such is the price for a safe, rich curve. At three full turns you can see that most of the fuel curve is very rich... again... sux but I feel I need to run it that rich overall just to compensate for the one lean spike at the end. Or do I???

 

I'm not trying to be a harbinger of doom or anything, really I"m not, but Cyg you really should make it a point to get down to the dyno ASAP, I've got a feeling you may be running dangerously lean. Also, why not try the FMU set at 3 full turns in, right in between the two points you've tried, and see how that feels? You may lose a bit of power, but it shouldn't bog or blow smoke. As I said, I noticed that at anything past 2.5 turns, even tiny adjustments seemed to make a LOT of difference, so I can see how even 3.5 turns would cause you to suddenly run way too rich. Get it on the dyno already! I'm very interested to see where our setups differ and where they parallel.

[Guest Cronic]

The runs from your first run, with the dynapack, seem more accurate to me. Just from expierence mind you, I was putting down at 15psi, just a FMIC, and 3" exhaust, MAF was messed with just a tad, 206rwhp/274rwtq on a Mustang dyno, which is similar to the dynapack, I believe they're both loading dynos, and read aprx. 10% less then a dynojet. However they're more accurate in my opinion, and much better to use when tuning a car.

 

The other dyno numbers just seem too close together, your tq numbers should be 50+lbs more then your horsepower. Remember the motors are very oversquare, and unless timing, fuel, or air is messed up somewhere along the run, you should be making about 290ft/lbs with 240rwhp.

 

Just from my expierence mind you. There might be some tweaking you can do that could allow for substancial power gains, with minimal effort.

 

On a side note, what are your plugs gapped at?

[Guest bastaad525]

*shrug* I have heard from others that the dynapack is more accurate. The torque number makes sense to me, unless something funny was going on. My first pull the torque was way up there, about 260ft lbs, which is only 10ft lbs less than what it was at the last place I dynoed on a dynojet. I can easily attribute that to factors like a) I'd heard the dynapack's read consistently lower, the dynojet facility was at a very low elevation, like 100ft above sea level, whereas the dynapack facility was at 500 or 800 ft... I forget, and c) it was a much warmer temp outside at the dynpack facility, as I was testing in the mid-late afternoon, whereas it was cooler at the dynojet, I was there early morning testing. And I knew torque was going to come down as I richened up the mixture. There is still some power left to be had on my setup... for instance, I'm still running the crappy, 2.5" pressbent exhaust, which, though I've been told MUST still flow better than say, a stock ZXT exhaust, I know it's still a big restriction and killing off power. Keep in mind as well I was 'only' running 12psi of boost, and was running pretty rich by the last pull (minus that stupid lean spike).

 

Being the yo-yo that I am, I did turn the boost back up a bit, now it runs at 13-14psi again. After looking at my overly rich a/f ratios on the dyno graph, and taking into account the new equations Sean73 has given me to play with I figure this should be perfectly safe afterall. So that should be good for another 10-15hp I think

 

My plugs are gapped kinda wide, at .050", I figured because I"m running the MSD I could get away with that? I get no signs of misfire under WOT/full boost.... and as far as my light misfire at idle, gapping them smaller (I've tried as small as .035") did not make it go away.

[Tim240z]

Bryan the dyno whore

[Guest bastaad525]

whore no more! I've sworn them off Shoulda seen the light and just bought my own W/B O2 a lonnng time ago... hell for the money I've spent dynoing I could have also bought a Gtech to go along with my wideband and had my own damn dyno right there! It will only take me one xmas and one birthday to rectify THAT mistake

 

 

TIM!!! Are you EVER going to dyno your Z????? You had expressed interest in doing so many moons ago....

[cygnusx1]

Yes, I set the FMU with the compressor hooked up to both FMU and stock regulator now. When I get past that 2.5 turn mark on the FMU adjuster, the fuel pressure gauge moves very quickly. At about 14psi and 3.5 turns in, I get about 65psi fuel, which bogs it down badly when driving under full boost. I think I will creep it up from 2.5 turns a bit at a time to get it as rich as it will go without bogging. I need to get a wideband. I already have a gtech. I also put in brand new stock injectors when I did the swap so they may be flowing a bit more than yours do. I also run with the O2 sensor connected and do see the ECU LED light blink as I cruise around town which indicates closed-loop mode. I may be running lean which explains me being able to just about keep up with that '96 Viper. I guess I should start being more considerate to my pistons and add a tad more fuel.

[Guest bastaad525]

Okay so... you had said you were getting 45psi when supplying ONLY the FMU with 14psi of boost, with the FMU adusted 2.5 turns in. What I really want to know is, with the FMU at that same setting, but BOTH the FMU and stock FPR getting supplied that 14psi of boost, what fuel pressure do you get then?

 

 

That's friggin sweet to have a compressor and be able to fine tune your fuel pressure like that.

 

 

You're right it is possible that your injectors are flowing more than mine. I will say, that whenever I pull my spark plugs, they are all very even, which suggests to me that the injectors are all supplying very close to the same amount of fuel. They aren't stock injectors, rather they are Python injectors, that my old mechanic put in for me when he did the swap. I saw them before he installed them and they looked new... at least, they were very very clean. However, I do consider the injectors as being probably the last possible suspect in my misfire problem, so who's to say how good of shape they really were? I will probably swap them out for either new stockers or a good set of used 370's soon as I just don't trust them. I'm still baffled at how differently our cars are running though... same injectors and same fuel pressure, but you're running more boost on a much more efficient turbo, and yet you're car is the one that bogs and smokes at that fuel pressure? Could your new injectors really be supplying THAT much more fuel??