First Dyno Run

[340ZXTTAZ]

Well after messing with z cars for many years I finally made it the Dyno today. I was hoping for better numbers but who doesnt right? Here is the specs on the motor:

81 N/A block bored .040 over with TRW pistons

Factory rods w/ arp rod bolts

Falpro HG and New factory turbo head bolts

P90A head with slight P&P and Shnieder cam .460 lift split duration 270 int. & 260 exh.

Factory intake and exhaust manifolds/ 60mm TB

T3/TO4E 57 trim turbo- open DP

Cheap Ebay intercooler and piping

Supporting fuel mods with Haltech F9 computer (Dinosaur, I know)

 

Here is the run with the most power. I know my a/r are lean in some areas and pig rich in the top end. 11-12 psi on all runs.What do you think about the numbers? Should I have more power or am I expecting too much from my little L28ET?

Edited January 8, 2010 by 340ZXTTAZ
Changed link and cleaned up the paragraphs.

[Chemicalblue]

pic too small, cant read the #s.

[340ZXTTAZ]

I changed the link to the img. see if that helps.

[Drax240z]

Appears lower than I'd expect, but the whole point of using the dyno is to make some changes and see how it improves things. Not sure how much smoothing is going on, but the sawtooth at 5700rpm combined with the 12.5:1 AFR would worry me a little, I'd want to see a bit more fuel from 5000-6000rpm, and maybe a touch less at 6400. 11.5:1 is a decent (safe) starting point.

 

How big is your intercooler inlet/outlet and piping?

[340ZXTTAZ]

The piping is 2.5" in and out and yes there are a couple of spots to change on the tune especially in the 4500-5500 range plus its way too rich at 6000-6500 mark. Still need to get back there and iron out the tune on the dyno, I ran out of time and $$$. Thanks for the input.

[jc052685]

I am gonna say something is holding you back.

 

I am just over 300whp with just 2psi more. My motor is a junkyard L28et. Stock everything within the motor. Cam, head work etc all stock. 60mm tb, biger turbo, open exhaust and an ebay intercooler.

 

I would think with the cam and portwork you would do more.

[datsun723]

Stock injectors?

[RedBeauty84ZX]

Numbers are a little low...you should be able to pick up a fair bit more power from a better tune.

[sileightygx]

i agree that you will see some better numbers with some more time tuning. what injectors are you running? if stock watch that injector duty cycle..you don't want a failure

[z-ya]

I would expect more too. My car made about the same power with the stock long block and turbo at 12psi. When I upgraded the turbo to a T04E compressor and stage 3 turbine the power jumped to almost 300WHP at 12psi. This was on a Dynapack BTW.

 

I agree with Drax240z, dynos are really only good for relative measurements. Except when comparing cars measured on the SAME dyno. Comparing absolute measurements on different dynos is not all that accurate. Use the dyno to get the most out of your setup by incrementally measuring the effect of changes you make.

 

Pete

[Tony D]

I would say the fueling is actually over-rich past your torque peak. We lost major power running anything richer than 12.5 almost every point past torque peak. From talking to people in general who have dynoed their cars and noted the changes, it seems that you need to actually pull fuel past torque peak.

 

For instance, on JeffP's car we started at something around 11:1 across the board, we started experimenting pulling fuel at various points watching EGT's as well. Some people said they tuned to 1650F, we didn't get anywhere near that point, but were amazed at higher rpms (with porting and a cam) that in some load bins we were actually running as lean at 13.8!!! Most of the stuff was in the high 12's, which was FAR LEANER than anything before torque peak.

 

I encapsulate this in a short synopsis, it took FAR longer on the dyno than we thought before we realized that running the same AFR past torque peak was actually too rich, and we were loosing considerable power.

 

Just make sure their datalogging equipment is calibrated properly, and stick with the same place to (as noted above) monitor relative changes from your adjustments.

[wigenOut-S30]

I would say the fueling is actually over-rich past your torque peak. We lost major power running anything richer than 12.5 almost every point past torque peak. From talking to people in general who have dynoed their cars and noted the changes, it seems that you need to actually pull fuel past torque peak.

 

For instance, on JeffP's car we started at something around 11:1 across the board, we started experimenting pulling fuel at various points watching EGT's as well. Some people said they tuned to 1650F, we didn't get anywhere near that point, but were amazed at higher rpms (with porting and a cam) that in some load bins we were actually running as lean at 13.8!!! Most of the stuff was in the high 12's, which was FAR LEANER than anything before torque peak.

 

I encapsulate this in a short synopsis, it took FAR longer on the dyno than we thought before we realized that running the same AFR past torque peak was actually too rich, and we were loosing considerable power.

 

Just make sure their datalogging equipment is calibrated properly, and stick with the same place to (as noted above) monitor relative changes from your adjustments.

 

what Octane was that on Tony? I would be quite scared to run 12:5 AFRs with 93pump gas. I guess Im just chicken heh, well that and have seen turbo cars melt pistons and ping de ping de ping at thoes type of AFRs on 93Pump.

[jeffp]

I was running C16 race fuel at the time. I have only tried to run (in CA) 91 octane pump gas with methanol, I have to say the methanol and pump gas got me some really impressive dyno numbers, and theengine stayed cool.

Back to the race fuel. I like Tony mentioned was tuning for the mid 11 AFR's and that was to rich for the car. The EGT's went out the roof, in fact I took a picture of my turbo and the whole exhaust turbine housing was glowing bright PINK (the jethot blue turns pink when the base metal gets that hot) So with some additional tuning, we realized the engine ran cooler and made more power in the 12.2-4 AFR range. Also, as Tony mentioned we were able to lean out the engine some more AFTER PEEK TORQUE! That is the key, when you are coming up on peek torque, make sure you have enough fuel or it will ping, well KINOCK loudly.

 

Also, the dyno testing will be little help to you in the car, but rather get you close, and even then it is schetchy. I have not completed ONE dyno run or tune time that I did not have to readjust after the dyno tuning. So my last attempt to do dyno tuning will be on an engine dyno, no car, no distractions, just engine tuning. We will see how that goes after the engine is installed.

You do seem low in power for your boost levels, but that is dependant on the turbo and the engine. So check out your application to make sure there is not something hindering the power output. Also, the comment was made that you would pick up the power with a better tune. Well even if you are rich like you are, you will only pick up about 20hp total from what you have now. Check the cam timing and make sure that is correct.

[Tony D]

My numbers were examples of pulling fuel after peak torque compared to what everybody seems to say which is 'Shoot for this AFR across the board'...

 

Jeff and I dyno testing (and Bryan as well) have seemed to mirror the fact that the engines make far more power by PULLING fuel after peak torque than by keeping it as rich as it was coming UP to peak torque.

 

That was the intent of the post, not to specify a magic AFR that should be used.

 

I mean, you got to admit---there is NO WAY I would have EVER thought we would have cool EGT and keep making power to 13.8AFR! But it did, and it was consistent.

[Drax240z]

I'm only advocating more fuel at that point because of the sawtooth, which depending on the dyno software smoothing may be hiding detonation. I've also only said that 11.5:1 is a safe STARTING point.

 

One thing I've found dyno tuning turbo cars, is that the power difference between 11:1 and 13:1 is pretty small, when compared with the other variables. (ie: timing, boost pressure) Less fuel after the torque peak is also consistent with my experience.

 

I'm still a bit surprised at the outright number, however the curve looks as I'd expect. The dyno setup could explain the low peak numbers. (Improperly entered ramp rates, inertial, ambient temps, etc... whatever that particular dyno uses for user inputs)

[jeffp]

I guess I should have worded it differently "I Mis spoke LOL LOL" What I was trying to get across was thyat the rich mixtures are just as damaging to the engine long term on the dyno.

The 11:1-5 AFR's are really bad in my opinion. The excess fuel going out the exhaust, on a turbo car has one more chance to be ignited, WHERE YOU ASK? In the exhaust turbine housing! That is BAD! Take a look at the picture I have on my webpage, the turbine housing got VERY hot and in my opinion the engine started going into thermal run-away. In fact, I will say that if you run the engine to 110 degrees C on a pull like I did ONE time, you just may find yourself with a bad valve seat around #4 in that area.

I put that car through FRICKIN hell that day, at least 25 pulls with full power. So it cost me a little, but I was able to figure out along with Tony that the richer AFR's in the 11 range up to peek torque only to serve to make the engine hotter then it would run with a leaner mixrture.

On the N/A car, the AFR's can be much richer then they need to be, and the waste is in the exhaust, no big deal, just bad fuel economy, but you take that same exhaust and run it through a very hot exhaust turbine housing and you start to run another somewhat of a second engine (the exhaust turbine housing) and that IS BAD.So the excessive heat is bad for the engine (cylinder head) and the pistons, depending on how they were honed to fit the cylinders. I have pictures of one build that the engine got very hot, and the pistons expanded about .0005 with the heat that left a nice 1/2" wide scrape mark in every cylinder. Was it enough to make a difference, in reality no, but none the less that is what happened to that build. The car got to 270 on the gauge and stayed there, the oil went to 130 degrees C and stayed there as well. I was out in the middle of the desert and really had not other alternative but to continue on and hope for the best. The next build the pistons were a little looser in the cylinders to provide the space for the pistons to expand and not cause problems running that hot for short periods of time.

Anyway, I'm all over it, I must find the correct solution to keep the engine cool, and I think I have, but testing will tell all. If the temp gets under control to my satisfaction with the modifications to the head and block I have made, then it will be a goal of 800 Hp, and guys (the nay sayers) I will run the rpm's to at least 9000 rpm's in that process.

So think about that, I don't think the honda boys will be able to compete if I can get the car to hook.

anyway

[340ZXTTAZ]

The runs were made with standard 91 octane from my local shell station. I'm running RC Eng. 550cc injectors and a base FP of 42 psi. I agree with the general concenssus that I need to work on the tune some more. I was just dissappointed with even those results. Plus I dont think that I will gain that much more overall like jeffp said. Seat of the pants it seems like a 300whp motor and I've been in plenty of 300+ whp cars. I was wondering about the cam timing myself. I'll look at the entire setup and see if I can find anything that would explain the #'s

Thank for the responses and advice.

[TimZ]

I guess I should have worded it differently "I Mis spoke LOL LOL" What I was trying to get across was thyat the rich mixtures are just as damaging to the engine long term on the dyno.

The 11:1-5 AFR's are really bad in my opinion. The excess fuel going out the exhaust, on a turbo car has one more chance to be ignited, WHERE YOU ASK? In the exhaust turbine housing! That is BAD! Take a look at the picture I have on my webpage, the turbine housing got VERY hot and in my opinion the engine started going into thermal run-away. In fact, I will say that if you run the engine to 110 degrees C on a pull like I did ONE time, you just may find yourself with a bad valve seat around #4 in that area.

 

This is an interesting topic that I'd like to expand on - Jeff, Tony, any objections if I take your posts and use them to start a new thread, so as not to hijack this one? I don't have time right now, but will try to get to it tonight...

 

EDIT: Here the new thread:

http://forums.hybridz.org/showthread.php?p=1111763#post1111763

[cygnusx1]

The runs were made with standard 91 octane from my local shell station. I'm running RC Eng. 550cc injectors and a base FP of 42 psi. I agree with the general concenssus that I need to work on the tune some more. I was just dissappointed with even those results. Plus I dont think that I will gain that much more overall like jeffp said. Seat of the pants it seems like a 300whp motor and I've been in plenty of 300+ whp cars. I was wondering about the cam timing myself. I'll look at the entire setup and see if I can find anything that would explain the #'s

Thank for the responses and advice.

 

My first hunch was cam timing. My second question was what are you using for fuel delivery?

[Zmanco]

I have a very similar setup with the same cam. I haven't dyno'd yet, but based on my VE tables in MS, my torque peak is right around 5k which is pretty close to yours. So you might eek out some more HP by retarding the cam, but that wouldn't increase the torque peak would it? Wouldn't that just shift the peak up a few hundred rpm or so (which would help HP of course).

 

Seems like you should have more torque based on what others have posted. Maybe the dyno just reads conservatively?