Dyno Results, Comments and Suggestions Welcome

[z-ya]

OK,

 

Here is my latest dyno curve:

 

http://www.sweetspotproductions.com/psanders/images/pete-dyno.jpg

 

Not bad numbers, especially the torque. It seems to me that I'm not getting enough air through it. Should be plenty of torque for close to 270HP at the wheels it would seem.

 

Here is the setup:

Stock L28ET long block with P90A (hydraulic lifters)

Spearco IC

60mm TB port matched to intake

Intake port matced to head

T3/T4b turbo (.60 AR compressor, stock ZXT turbine)

K&N Filter

2.5" exhaust with Scottie GNZ downpipe and Borla muffler

Wolf EMS (fuel and ignition)

12psi boost

Timing at full boost around 24 deg advance

 

Is the stock turbine limiting my HP?

 

Comments and suggestions welcome.

 

Pete

[Guest bastaad525]

 

Not bad numbers' date=' especially the torque. It seems to me that I'm not getting enough air through it. Should be plenty of torque for close to 270HP at the wheels it would seem.

 

[/quote']

 

I'd say, just going from looking at my own dyno charts, that the max torque to max hp ratio is just about right. In general, the L28et setups I've seen dynoed always seem to put down 15% or more, torque over hp... sometimes to the extreme (Sleeper Z who dynoed ~300rwhp and ~400ftlbs). I've also seen very few L28ET's dynoed so far that didn't start falling off in torque by about 4500rpm... which is part of why hp peaks so relatively low... most people blame this on the relatively inneficient head design (talking about flow capability, not referring to the hydraulic head). Hp usually peaks between 5000-5500rpm. I pay more attention to torque anyways (and you have plenty of it!), as this really says how strong your motor is, with HP really only saying how high in the revs it can pull, and our motors just aren't designed for really high rpm pull.

 

 

I will say this though, taking another glance at your setup, I would expect much more than 220hp... I could hit that with my stock T3 at maybe 13ish psi on stock EFI and possibly even w/o the I/C if I had a good exhaust and a bit more fuel... I'd expect you to be closer to 300hp.

 

What are you running for fuel injectors? stock or larger? Increased fuel pressure? If you're running stock injectors, even with increased pressure, and even with the programmable EFI, I'd think that would be a bottleneck for sure... but given that your fuel curve stays very nice the whole run I'm assuming you have bigger injectors and just didn't list them? Or is that part of the wolf EMS?

 

maybe not enough timing? If you're running the hydraulic head I'm assuming that's an '83 motor... '83's run 24* BTDC at IDLE... whereas you're running 24* at full boost? I'd think there'd be room there to advance the timing a bit... and timing seems to make a lot of difference in power on turbo setups.

 

that's the only other thing I can think....

[z-ya]

Thanks for the reply.

 

I'm using 8 ZXT injectors, one for each cylinder, and then two in the IC discharge pipe. These are on 98% of the time that the primary injectors are. If you look at the A/F ratio, it pretty much dead on at 12:1, so I don't think it has anything to do with fuel. I may need to play with the timing a bit more.

 

Pete

[Drax240z]

Do you have a 2.5" exhaust all the way back? It seems others (I haven't tried this myself... yet) have got noticeable gains from going with a 3" mandrel bent system over a 2.5" system on the turbo cars. Scottie-GNZ keeps calling it the "best bang for your buck mod you can do to a turbo L-series" and I'm inclined to believe him.

 

I love that torque curve. I agree it looks like you need some more top end breathing though.

[Mack]

that is a nice torque palteau! lol! I would agree with drax. a 3 inch exhaust system would probably help you out a bit. i know a guy named JeffP on here sells them. there were dyno charts posted on zcar.com a while ago. on a completely stock 280zxt, just by bolting on jeffs 3 in exhaust system the car picked up 20rwhp. yes, 20 rwhp. went from 149ish to 169ish. pretty crazy.

 

Mack

[Pyro]

good numbers!

 

But I think your ignition timing is low. 28 to 30 degrees should be possible. I used 28 degrees on a T3 and 12 psi of boost running a very lean 14.7 a/f ratio with an spearco IC and made 235 hp.

 

12.1 seems too rich. I thought 12.7 was ideal for power.

 

yes, the stock turbine could be hurting max HP. A stage three wheel would be helpful but will spool up 400-500 rpms later. And you will lose a little low end torque but gain another 1000 rpms.

 

Extra injectors in the ic tube is a nice mod!

[yo2001]

30 deg is too much timing. I think I was only getting around 25 deg peak under boost.

 

I would throw more boost at it. looks like you got enough fuel

[240hoke]

Yeah thouse numbers look pretty good, but i agree with everyone else you should be getting a good bit more. I put down 305 ft/lbs at 11psi, this was on a mustang dyno too(lower numbers).

 

Defintly check into the exhaust/muffler combo. I had a 3" system with a flowmaster muffler. When i swapped out hte muffler to a magnaflow i noticed a big improvement. So i say 3" all the way with some sort of straight through muffler.

 

You could mess with the timing, just take a couple degrees out and see what happends on the chart, just play around a bit and yoiu can figure out whats good for the car.

 

 

-Austin

[yo2001]

powerband looks too smooth to have not enough timing IMO

[datsunan]

Hey Pete I'm taking my JWT 400 to the dino on friday I'll let you know how it charts. I'd also agree it may be in your timing. If you are using an upgraded ecu from wolf they say 20deg at idle as to the stock ecu setting is 24. I'm going to dino just for that reason I'm having a hell of a time with my timing, I'm going to make timing adjustments and do multiple pulls. I hope to be putting down 300+. I'll let you know. Paul

[Guest bastaad525]

30 deg is too much timing. I think I was only getting around 25 deg peak under boost.

 

I would throw more boost at it. looks like you got enough fuel

 

 

Yeah he COULD do that, but I would think the REAL issue is, he should be making MORE power for the amount of boost he's already running. 12psi on a HYBRID turbo, intercooled, with plenty of fuel... should be way more 220hp to the wheels dont you think?? I can get close to that on a stock turbo, if I installed my I/C (still got no I/C and made 200rwhp w/o it), bumped up the boost 2 psi to 12, threw some extra fuel in there via an adjustable FPR to get a nice 12.5:1 A/F ratio, and still running my 2.5" pressbent exhaust, I bet I could hit that same hp.

 

To me this means there may be something wrong, some bottleneck that he should figure out BEFORE he just goes throwing more boost at it. Maybe even some 'free' power there to be unlocked, maybe the exhaust I dunno but I doubt that would be the only thing. If you guys are saying timing is alright then something else must be amiss....

[yo2001]

Well, The graph looks like it's not a dynojet. The dynojet is optimistic with the number than others. So can't really compare with the dynojet graph. And the turbo holding 12psi at redline? could be that boost isn't holding.

 

And we don't know the trim on that hybrid turbo. I was running 60-1 and that's alot bigger than V trim. And stock turbine wheel will make less power than bigger turbine wheel. Prolly not much less at that power level.

 

Also he's little on rich side, less power.

 

May be, go back to dyno and see if timing helps on the dyno but it's not safe to start adding timing without knowing if there is a knock or not. We have blown a turbo B16a by adding too much timing (27 deg) a day after a dyno. my 2 cent.

[Guest bastaad525]

Well, The graph looks like it's not a dynojet. The dynojet is optimistic with the number than others. So can't really compare with the dynojet graph.

 

 

Um... I know the graph looks a little different from mine but it does say dynojet research right at the top there. So comparing apples to apples, the hp seems a little low. If it's not a dynojet then of course all comparisons go out the window. I dont know enough about trims and all that to say anything about his particular turbo I guess, but I know when I think T3/04, I think much bigger power numbers than what I'm capable of right now with my own car. But, whatever trim he's running, I would think his turbo has GOT to be better than stock... otherwise why 'upgrade' at all. And since I know I could hit that power level at 12ish psi on a stock turbo, I would just expect more from a hybrid... AND he's running programmable EFI and you know that should be good for even more power. I thought it odd about the timing thing... I have never watched the timing on my turbo while under load and in boost... I just knew that at idle it is set to about 20*, and that it advances well past 30* when revved in neutral... I didn't know the factory ECU would pull so much back out as boost came on. Sorry if I gave wrong info there, but it was the only thing that clicked right away as being a possible cause. It would help if he could have seen what his total advance was getting to under WOT and full boost... since he's running programmable spark, maybe his retard under boost is too much?

[z-ya]

Thanks for all the comments and sugestions. Here is more information:

 

Yes, it was tested on a Dynojet. It doesn' t look like most printouts, because I just grabbd the files off the dynojet computer and plotted them at home using the Dynojet viewing software.

 

The EMS I'm using doesn't retard under boost, it has a 3D map for ignition (pressure vs RPM vs advance). So no retard is happening, it's around 24deg at full boost.

 

I don't think the pressure is dropping off, but I wasn't watching the boost gauge, I was watching the tach. When I drive it on the street, the boost sits in the 12psi area when I have it floored.

 

I'm not sure on compressor wheel, all I know that it is a .6 AR T04B, with the stock 280ZXT turbine. I bought it used, and had it rebuilt. You are right though, it's got to be better than the stock one.

 

I stilll think I'm not getting air through it.

 

Pete

[Guest bastaad525]

Z-ya - I definately think you could run at least a couple more degrees of advance under boost, and a couple of degrees can make a lot of difference sometimes. I was actually mentioning in another thread, and I'm surprised yo2001 didn't bring this up himself here, but I found an old post of yo's where he fiddled with timing on the dyno and got over 20 extra ft lbs of torque from advancing 2 degrees of timing and nothing else... so you can get big gains from timing. Wish I had watched my timing on the dyno....

 

 

what makes you think you're not getting enough air thru it?

[yo2001]

I need to find my dyno graph to really show why I needed more timing but before I raise the timing, the power band was real erratic. looked like the flame was getting blown out. So we (dyno operator and I) gapped the plug down redynoed, same result. Then check the base timing and it was up to fatory spec (or something close) so I turned alittle to add timing. And yes gained alot of power and the curve really smooth out.

 

But I'm don't want to recommend anyone to add timing because I gained HP from it. Remember I was working with real conservative stock Z31 ECU timing.

 

And With EMS, you are and should be retarding timing via pressure and airflow. prolly 30-35deg cruise timing, and 24deg WOT depending on the rpm. (I was told should be less after the peak VE) if you are getting 24 deg under cruise condition, you'll waste alot of gas.

 

Here is my Talon's timing. 35 deg under cruise, 22-23 WOT decreasing toward 17 at redline. with 10 deg at idle.

[Guest bastaad525]

heheh I know ... I just point out your example because it still amazes me just how much power difference it made... but in your case you KNEW that was what you needed, I remember how the curve looked before and after. For me it was a good example of what a couple more degrees of timing can do.

 

Well... there is still the issue here of, if it's not his timing, and most likely not the exhaust (though that would help), what IS the reason for his lower-than-expected power? Surely there could be some other things he could check?

[yo2001]

Here is couple things. Looks like the power is peaking early. 220 at 5000rpm. Could be from going rich there A/F ratio or the cam timing is little on advance side.

[TimZ]

Before you start messing with the timing at WOT, do you know what your exhaust temps are? If the timing is to retarded, I would expect to see high EGTs.

 

Also, I seriuously doubt that the 12;1 afr is causing any huge problems, and would recommend trying to lean it out much past that, at least not until you have a better understanding of what is going on.

 

I'd be looking for breathing restrictions - the 2.5" exaust is suspect. Also, what size is the intercooler piping? How about the cam?

[z-ya]

Stock turbo cam, 2.25" IC plumbing, cam timing is set to stock.

 

I just uploaded an image to the Photo Album of my ignition timing map.

 

It seems like I have enough fuel, the timing is pretty much where it needs to be. The only thing that I feel is restricting power is the overall air moving through the system.

 

Comments welcome,

 

Thanks,

 

Pete