Finally got the car dynoed, and of course, I'm not satisfied

[MarkEmark]

As the title says, I finally got around to getting the car tested today to see what it'd put down, and it was 50 whp less than I was hoping for

What's amazing is how fast it feels even at this level...I can't even imagine what it'd feel like if it were making how much I was hoping it to make.

-Weather was miserable: muggy, humid, hot, 87 degrees

-Only one external fan was used on the car, and it looked to be rather small--it wasn't one of those huge diameter industrial type fans, but one of the smaller ones that looked like a turbo snail. The WRX next to mine being tuned had one of those huge industrial sized fans AND two of the small ones. Of course, me being non-confrontational and non-assertive, I didn't bother saying anything about this.

-I didn't even get to do the pulls! No clue why, apparently this is their policy. All pulls were done in 3rd gear.

-Quick break-down of the specs: fully built engine, 9:1 wisecos, crower rods, arp head/main studs, cometic MLS HG, 3 angle competition valve job, PDM stage II cams, ferrea oversized (+1 mm) intake/exhaust valves, methanol injection, electronic exhaust cut-out (meaning all these pulls were done essentially using an open downpipe), JWT turbo ECU, Cobra MAFS, 50 lb/hr fuel injectors, adjustable aeromotive FPR, standard JGS log manifold, T3 super 60, .63 a/r turbine, stage III wheel, 360* thrust bearing, .60 a/r compressor, boost logic turbo blanket, koyo radiator, mechanical fan in place, ACT street clutch, fidanza flywheel, ASP crank pulley, LSD, 29 psi in 245/45/16 Yokohoma AVS sport tires. Running 22* BTDC at the distributor. 93 octane gas.

-All runs were taken on a Mustang Dynamometer. I've heard these read low compared to others, at least that's what one of the guys said. All of the figures were "SAE corrected" according to the guy.

-Best run: 283 whp, 309 rwtq. I'm pleased with the torque, but definitely not with the horsepower.

-A/Fs when this power was made: 11.7-12:1 (ie, NOT RICH AT ALL, actually a little on the lean-side, but this is fine because the methanol more than helps out here).

I really don't understand. This engine is only making about 40 more whp than all of those bolt-on kits make right out of the box on stock engines at around 8 psi. It makes no sense to me. Compression was tested a few days ago and is 166 psi across the board. Car runs perfectly, is not running rich, and the boost stays relatively constant.

So why in HELL am I about 50 whp down from what I should be making?!?! I'm sure ~10-15 more hp could have been made advancing the timing at the distributor, but I didn't have anything to record timing with me at the time.

Here's a pic of the dyno graph. Blue line is torque, red line is horsepower, orange line is boost pressure. My dad forgot to bring the digital camera to take a video (d'oh), but it sounded so beautiful. That's the first time I've ever heard the car from outside, and wow. Too bad it's not putting its money where its mouth is, so to speak.



Of course, dyno certainly does not reflect the unbelievable amount of time, money, and heart poured into the thing.

I cannot for the life of me figure out why the torque curve falls so flat after peaking around 4250 rpm...the boost does drop a little there, about 2 psi, but if you look at the line, it also increases a little bit past 6000 rpm, yet the torque still decreases.

I'm contemplating taking it to a different dyno test facility that doesn't use a mustang dynamometer, but that'd just be another $75 or so and more wear on the engine.

[KATwo40]

I think it looks like a good useable power curve, myself. The reason the hp didn't reach up there further is that the super 60 runs out of breath on the top end. It exceeds the choke line on the compressor map, so you end up just pumping hot air, rather than taking in more lb/min.

Also, it looks like your boost falls off a bit after the peak is reached. That is also indicative of a loss of flow on the top end. Notice how the boost loss on the chart pretty much matches the torque loss. That's a direct indication.

I think you've done an exceptional job on your build and should be super proud of yourself. Drive it like you stole it. It has plenty of useable torque, and looks like a GREAT setup for autoX or road course running.

Also, I think the AFR's are good.

I say "props" on a job exceptionally well done. Don't go to another dyno. Mustang dyno's are probably the most accurate on the market. Those and DynoDynamics units. DynoJet dyno's usually read higher and are generally less accurate.

[j-z]

what were you boosting at on these runs? i know the reason why youre only making a lil more than those kits at 8psi. its because all of those kits come with t3/t4 turbos. youre running a straight t3, so thats why youre not getting as much.

[KATwo40]

I think he's peggin' about 15psi, then it falls off.

Yes, most of the off-the-shelf kits do use a T3/T4 hybrid. Many more total lb/min than the super60.

Either way, it's a job well done.

[Florida240sx]

What psi was this at??

[Jookmasta]

what psi was this at? i re-read the post twice and still cant find where u mention it at? boy arent u gonna be pissed if i make more hp than u lol.

on a serious note, i agree as to ur questioning of the torque curve and hp curve. ur running aftermarket cams so technically there shouldnt be a drop in the hp curve and i would definitely expect you to make more hp than that with those cams. i made 246rwhp with mine at 9-10 psi with a doodoo safc tune and base retard of the timing. what did u make previously if u dont mind stating (as supposed to me searching) and at what psi level was that at?

[SeVa-S13]

Ouch, that's a harsh drop in the torque!

I wonder how well a 50 trim would do here, all else being equal?

[Jookmasta]

the 50 trim would not have had that kind of drop in torque and obviously make better numbers. i didnt realize how bad of a drop in torque that is till u pointed it out seva. unless my eyes are bad, that's a 100 lb/ft drop in torque from 4200 to basically redline.......................

[crzycav86]

I think you should get a tubular manifold. You would probably have a very good gain throughout the powerband.

Also, your turbo is most likely becoming a heat pump at 15 psi. Where did you learn that it can flow at least 330whp worth of air? Have you seen any other kat/similar motor reach that power with that turbo?

[KATwo40]

what psi was this at? i re-read the post twice and still cant find where u mention it at? boy arent u gonna be pissed if i make more hp than u lol.

on a serious note, i agree as to ur questioning of the torque curve and hp curve. ur running aftermarket cams so technically there shouldnt be a drop in the hp curve and i would definitely expect you to make more hp than that with those cams. i made 246rwhp with mine at 9-10 psi with a doodoo safc tune and base retard of the timing. what did u make previously if u dont mind stating (as supposed to me searching) and at what psi level was that at?

If you squint your eyes hard enough, you can make out the orange print on the bottom of the dyno chart that indicates the peak boost pressure.

Having larger cams doesn't compensate for a turbo running out of breath. Follow the boost and torque lines together and note how the drop in boost pressure nearly identically matches the torque drop. This is a direct indication of a "too small turbo" for the desired power.

I took the liberty of mapping out the super 60. Here are the perameters I used for a boost pressure of 15psi:

PR = 2.31 (factored in a 2psi drop across the system, 1psi drop on the intake created by the MAF and air filter)

Max RPM = 6800

Boost Threshold RPM = 34000

Altitude correction = .0997 (about 1,000ft ASL)

Using these parameters, his engine would need an airflow of about 56lb/min to sustain 15psi @ 6800rpm. Obviously more heat = less lb/min, but that's not good boost...that's just heat.

If you look at the map below, you'll see that the super 60 runs out of breath around the 4500rpm mark (which is also shown on his dyno chart).

Pardon my squiggly mouse drawing. Click for large view.

[1WheelWonder]

Mark I would retest at a different facility, one where they will let you make the runs, all of them do down here, and run your car in 4th gear, it does make a significant difference. I've got a friend who owns a Dynojet and before recently spinning a rod bearing he let me and some buddies use the hell out of it for the night. At 9psi in 3rd gear I made around 220-230 iirc (sheets are at home) and in 4th gear I made 267hp at the same psi. I cannot tell you why it makes a difference, because i'm uncertain of why it does, maybe someone could pitch in, but the differences were evident on every car we dynoed that night.

[klattr1]

get a GT32 (.63 ar) turbo from Turbo240....then you'll have great response/spool (which you mention is important to you) and plenty more HP potential...with that turbo and stable boost (right before peak TQ all the way to redline), you curve should look alot better....

[S14tat]

Mark I would retest at a different facility, one where they will let you make the runs, all of them do down here, and run your car in 4th gear, it does make a significant difference. I've got a friend who owns a Dynojet and before recently spinning a rod bearing he let me and some buddies use the hell out of it for the night. At 9psi in 3rd gear I made around 220-230 iirc (sheets are at home) and in 4th gear I made 267hp at the same psi. I cannot tell you why it makes a difference, because i'm uncertain of why it does, maybe someone could pitch in, but the differences were evident on every car we dynoed that night.

its becasue in 4th your going at a 1:1 gear ratio. vs third gear where your under driving the engine.

[hannibal]

Marc, I dont think your numbers are too bad. T3/T4 setups make 300whp at 12psi (no idea what kinda torque) and youre just below that. Mustang dyno do read lower than others, they were 3rd gear pulls, and youre running 9:1 CR. The real question is have you dynoed at this place before? How did your previous numbers compare?

The drop off of torque seems to be a factor of the turbo. I doubt it can do much more than 300whp and youre right there. But I cant think of a reason why the boost drops, then rises slightly at 6000rpm.

[KATwo40]

You guys just don't understand the way a Mustang dyno works. It's a steady-state unit, meaning it can sustain variable loads on the rollers.

You can use 3rd gear just fine. The Mustang dyno software will compensate for your gearing choice and change the load accordingly. Remember, the difference between 3rd and 4th gears is no different than what you'd get if you ran different size tires with a different rear diff. ratio. In the end, it's all just gearing.

DynoJet dyno's are inertia units. They're good for WOT only, with no varying loads. Therefore, that's why you see different #'s when altering the gearing on a pull (whether that's trans gear selection, tire size, rear diff size, etc.).

The Mustang is preferred over the DynoJet by engine tuners because you can use this loading feature to tune each cell in the ECU mapping.

Just thought I'd toss that in there.

The bottom line is that the T3 Super 60 on this car is maxed out. It has no more power and has made pretty nice numbers for what it is. Maybe some more in-depth tuning could squeeze out a few more hp, but not enough to really matter (10-15hp at most, I'd say).

The small boost spike near the end is likely a heat surge. Remember, boost can be made by excessive heat, which I'm CERTAIN is an issue with the super 60 @ 15psi around 6,000rpm on the KA. If you'll look at the map I posted, you'll see that 15psi is pretty high in the map, making for higher intake temps.

[MarkEmark]

If you squint your eyes hard enough, you can make out the orange print on the bottom of the dyno chart that indicates the peak boost pressure.

Having larger cams doesn't compensate for a turbo running out of breath. Follow the boost and torque lines together and note how the drop in boost pressure nearly identically matches the torque drop. This is a direct indication of a "too small turbo" for the desired power.

I took the liberty of mapping out the super 60. Here are the perameters I used for a boost pressure of 15psi:

PR = 2.31 (factored in a 2psi drop across the system, 1psi drop on the intake created by the MAF and air filter)

Max RPM = 6800

Boost Threshold RPM = 34000

Altitude correction = .0997 (about 1,000ft ASL)

Using these parameters, his engine would need an airflow of about 56lb/min to sustain 15psi @ 6800rpm. Obviously more heat = less lb/min, but that's not good boost...that's just heat.

If you look at the map below, you'll see that the super 60 runs out of breath around the 4500rpm mark (which is also shown on his dyno chart).

Pardon my squiggly mouse drawing. Click for large view.

What I don't understand is that apparently T3 super 60's come in different sizes, unless my last turbo wasn't actually a T3 super 60 (despite being purchased believing this), because my new T3 super 60 is SUBSTANTIALLY larger in the compressor wheel and compressor housing compared to the old T3 Super 60...so how do I know the map you're using is actually for my turbo's compressor wheel? It most likely is, because the dyno graph doesn't lie, and the torque curve should not drop so dramatically like that.

The turbo is definitely not choking the engine though, the turbine and turbine wheel are plenty large, so it's obviously a matter of the compressor not being able to flow enough.

For the runs, 15.4 psi was the MAX the engine saw...and if you look at the line, it only stays at 15.4 psi briefly...by the time the engine was at 6000, the psi was only about 13 psi...so a 2.4 psi loss = ~20 whp right there.

Also, I've read a few articles about mustang dynos versus dynojets, and I now feel better about my power level...some places were quoting a 10% higher reading for a dynojet versus a mustang, meaning 283 whp is more like 311 whp, and 309 rwtq is more like 340...

I could take it to a dynojet so that I can make a more valid comparison of my numbers versus others' set ups (because almost everyone else quoting numbers are quoting dynojet numbers), but that's not going to change the fact that the torque drops so dramatically and that 2.4 psi is lost. Between peak torque @ 4250 rpm and redline, the torque drops from 309 to about 200...that's a huge loss in torque. At max power around 5750 rpm, torque is only about 250...using the formula for horsepower, if the torque were 300 at 5750, the corresponding horsepower would be 328 whp, and again, this would be MUSTANG dyno whp.

I'll look into the AMS GT32, it's too bad it's $650 though, that's a lot of cash, but I'd be able to sell my turbo for a good amount of $; it was brand new only 2000 miles ago. I may get the GT32 assuming the 5-bolt discharge is the same pattern as my current turbo (allowing me to use the ol' internal wastegate). Maybe someone over at AMS is feeling generous and would send one my way just for testing purposes If it doesn't fit my internal wastegate swingvalve, it's going to be a PITA finding a turbo that does fit it...

Also of concern is whether or not this turbo will fit my current set-up...there's not a lot of wiggle room and I don't feel like re-fabricating the downpipe. Who actually makes the GT32, and is it a standard .63 a/r turbine? What trim wheel?

[hannibal]

Its a standard Garrett GT32 modded by AMS. They never post the specs or say exactly how they mod it, and I personally would have to get an answer to those question before buying one.

I know JGS says their downpipe fits T3's and the GT32 so you shouldnt have a problem reusing your wastegate/DP.

And seriously, you say the car is a blast to drive. The car's running fine and the motor isnt going lean. Enjoy it for a while man, youve worked hard enough on it as it is...

[KATwo40]

And seriously, you say the car is a blast to drive. The car's running fine and the motor isnt going lean. Enjoy it for a while man, youve worked hard enough on it as it is...

I couldn't agree more. As I've been saying the whole time, it's a job well done and you've gotten some good numbers out of that turbo. You should just drive that sucker and have fun with it before changing it all up again.

If it makes you feel better, I'll be using a Mustang dyno when I do my tuning in a couple months. You're welcome to compare with my numbers, if you need to.

[Jookmasta]

i wholeheartily agree with the 2 previous posts..............remember what ur goals for the car are. is it to have a nice reliable ka-t thats a blast to drive or to have a dyno sheet saying you made 350 to the wheels? if you love how the car feels, then dont upgrade the turbo. im not trying to dispersuade you but just cause you didnt make the numbers that you wanted, doesnt mean that the car isnt fun to drive right?

sidenote tho, me and you are in a similar pickle if we were to upgrade to a gt32 (this is the only turbo i would upgrade to). it would be great for it to work with the internal wastegate assembly and mate up right with the current DP's on our cars.

[j-z]

i think the most practical thing for you to do would be to upgrade the compressor side of your turbo. that way you keep the internal gate side and same dp. take it to a turbo place and itll prob cost around $200 to upgrade the entire compressor side. thatd be the cheapest and easiest thing to do.

[MarkEmark]

i wholeheartily agree with the 2 previous posts..............remember what ur goals for the car are. is it to have a nice reliable ka-t thats a blast to drive or to have a dyno sheet saying you made 350 to the wheels? if you love how the car feels, then dont upgrade the turbo. im not trying to dispersuade you but just cause you didnt make the numbers that you wanted, doesnt mean that the car isnt fun to drive right?

sidenote tho, me and you are in a similar pickle if we were to upgrade to a gt32 (this is the only turbo i would upgrade to). it would be great for it to work with the internal wastegate assembly and mate up right with the current DP's on our cars.

You guys are all right, I wouldn't even think of upgrading the turbo unless I had the car dynoed and saw the torque curve...sure doesnt feel like it's losing that much torque after 4250 RPM. However, I am never satisfied, it's just my personality, and it's the whole reason this car has become so incredibly modified as it has...I'm always looking to tweak this or upgrade that or re-do this and that, and now that I know the turbo is robbing it of, realistically, at least 30 whp, I want to remedy that.

Talked to Chris at AMS, and the turbine side of the GT32 has an identical 5-bolt pattern to my current turbo, meaning my internal wastegate assembly/downpipe would bolt right up (it has the same size .63 a/r turbine too).

I think I'm going to upgrade to the GT32...I can probably get $400 for my turbo on ebay (it was brand new 2000 miles ago), and then I lose $250 to pay for the other turbo...not too bad, and it's not a big deal to swap out turbos, I've had the turbo off plenty of times.

Not to mention, if I can run lower boost on the GT32 and still make as much power as I currently am, it's win-win.

Let's hope AMS has these suckers in stock.

Nex time I dyno I'll bring it to a dynojet with the GT32 and see if she can't make 330 whp @ 15 psi (ACROSS THE ENTIRE REV RANGE, OF COURSE)

[Florida240sx]

My turbo my be on it's way out so was looking to get one of theirs as well. Then rebuild mine once my other project begis or sell it to my friend.

[pr240sx]

If aint broke, dont fix itIf you car runs great now, leave it like that!!Enjoy, smoke some ****ty mustangs and then upgrade if you need it.Also, consider that you will get more power if the car at the street, whre the air cools down the intercooler.

[bruinbear714]

What PSI were you running? The torque curve looks normal for STOCK cams, but since you the have PDM cams, I'm going to have to say that the timing is a little on the conservative side, or the turbo is a little on the small side for the amount of power you want to push.

Take a look at my dyno results at the bottom of the page. http://www.frsport.com/information.php?info_id=9

That's with completely stock internals with 91 octane gas. 286ish ft/lb of torque at about 11.8 PSI of boost with AFs in the 11.5-12.

[Jookmasta]

u know after looking at ur graphs over and over i have come up with the conclusion that perhaps the car was heat soaked. im not inferring that you had cooling issues but it just seems that something like that would be expected from a car that has been driving around town in the middle of the day.

[KATwo40]

Heat soaked or not, good intercooling can't overcome a compressor's inability to pull in more lb/min. The bottom line is that the turbo is too small to make much more power than he made, and too small to maintain the boost/torque levels he wants. The compressor map never lies.

[newbe40]

Keep us posted on your next dyno with the gt32 that would be a very interesting to compare the before and after.

Nice setup, i hope you go for the gt32 soon I think it make a big difference !

[nelson8708]

its fast...its bullet proof......its a built ka.

[MarkEmark]

What PSI were you running? The torque curve looks normal for STOCK cams, but since you the have PDM cams, I'm going to have to say that the timing is a little on the conservative side, or the turbo is a little on the small side for the amount of power you want to push.

Take a look at my dyno results at the bottom of the page. http://www.frsport.com/information.php?info_id=9

That's with completely stock internals with 91 octane gas. 286ish ft/lb of torque at about 11.8 PSI of boost with AFs in the 11.5-12.

15 psi max, but by 6000 rpm, it was probably more around 13 psi. Again, I was using a mustang dyno, not a dynojet, which apparently measures about 10-15% less than a dynojet (what everyone else uses).

Timing is probably still a little conservative, but it's already 22* BTDC base timing, so I prob wouldn't advance it much more than a degree or 2...

As far as heat-soaking goes, the engine definitely was not. I have a 2.1" all aluminum koyo radiator, am running 70/30 water, water-wetter, and have an efficient front mount oil cooler. As far as a heat-soaked intercooler, I also doubt it....the ambient air definitely wasn't on my side (87, sticky, muggy, humid), but I don't think it was heat-soaked. The intercoolers pretty large and is well placed for a lot of air-flow but as has been said, the fans they used while the car was on the dyno was definitely not adequate...I have an oil cooler, an air filter, and an intercooler all up front needing air. Consequently, I'll definitely not re-test there.

I'm still planning on getting the GT32, eventually, but it may not be as quickly as I hoped (some dumb, careless broad backed into my car and did about $300 worth of damage to the fiberglass bumper, refuses to admit to it, and is being a real whore, but thats a WHOLE other story that I'm not getting into).

Anyhow, when I do get it re-dynoed, it'll be done at a different facility, one with a dynojet. I want numbers that reflect what the vast majority of the community uses to measure whp.

[shockload]

the main reason stock engines make more power is becauze the are .4 higher compression then your engine. . its the same with a stock sohc you just run more boost, simple as that.