What could be wrong? Not making the power I thought I would.

Cox Abele · Feb 24, 2015

Sorry for the wall of text, but here goes.

I've had my car dyno tuned twice on two different setups. The first was on Central Florida Turbo's Mustang Dyno by Jestr. We managed 325hp/320tq. This was the setup:

FWD/5-speed, FMIC and hard pipes, turbo inlet pipe/K&N, Turbo Lab cast 20g-TD05H, 2.5" DP to e-cutout in place of the cat, stock CBE, BSE kit, ported 2g manifold, ported exhaust housing, ported 2g o2, supporting mods, 22psi.

I fried the clutch driving back to Virginia, so I never really drove the car after that. A few months passed and I got the car in the garage and did a fairly significant amount of stuff. It may have also had a significant boost leak at the intake manifold to head, but I don't know if it was present at the time the car was on the rollers. The exhaust cam may have also been advanced one tooth, but there's no way I can 100% prove that.

Coming back out, I'd have to have it dyno'd. This time I had Chris at Moore Automotive dial the car in on their Dyno Jet. The new setup was a bit more advanced.

AWD/Auto/Stock converter/ FMIC and hard pipes, turbo inlet pipe/K&N/ Turbo Lab Billet 20g - TD06SL2, Full 3" Turbo back exhaust, BSE kit, rebuilt 1G TB, Evo3 Intake, Comp's 272 cams not degreed, same ported manifold and o2 housing. Boost leak tested to 30psi.

We dialed the car in at 20psi. I was having waste gate issues which I fixed when I got home. At 20psi, it made a whopping 284hp/246tq.

Wastegate issues fixed, I ran the car at the shootout and trapped 103 (3480lbs!) at ~28psi. That's about 320hp.

I haven't bothered with the car much after the shootout. Discouraged with the results, I've had zero drive until tonight. I opted to do a compression test and gained the following results:

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After 6 months of delay, I've finally cracked and decided it was time to work on the car. Brought home a compression tester from work just to see how things were going. I didn't have a helper to watch the gauge, so I had to crank the car over (6 revolutions each cyl) then run to the front and check the gauge. I also ran a cap full of oil in each cylinder for a wet test. I did added oil to all cylinders at the same time, so I suspect that my numbers may have been skewed on the wet test towards the end. Anyhow, I worked 4-3-2-1 on each test. Did it with the engine warm. Doesn't smoke, doesn't burn oil, never blown the dip stick out, fuel filter between the VC and turbo inlet pip hardly has any oil in it. The short block is stock (RVR/JDM), the head is a stock Advance Auto Parts reman with non-degreed Comp 272 cams.

Let's hear your thoughts...

Now, I know my car is heavy, and it won't launch worth a damn due to a tight converter (2100rpm limit, 3psi no matter what launch control settings are used). I also know the AWD/Auto will consume horsepower figures, but the track doesn't lie. The compression test wasn't due to being suspect, just for further knowledge as to what may or may not be going on. I figure with a bigger turbo, more pressure, larger profile cam and better intake setup, I'd surely surpass my previous dyno figure. I guess I have a bit of figure envy seeing a 16g and supporting mods eclipse my cam/intake/port work numbers.

What could be wrong with the setup?

MJBean420 · Feb 24, 2015

what are you using for tuning?

Cox Abele · Feb 24, 2015

ECU Flash / Evo Scan / Tractix 2.0

98yctuner · Feb 25, 2015

Do you have 1g cas? If so, try advancing the timing a bit and go from there. Same situation happened to me a while back in my gst and I advanced my timing on the cas and BAM it really woke the car up.

bastarddsm · Feb 25, 2015

I'll bet your valve springs are junk.

DSMTyson · Feb 25, 2015

^very possible. With worn out stock springs and 272's I got out ran by a stock cobalt SS-T when i was on 18psi on a td05h 20g

Macspsi · Feb 25, 2015

Running about the same setup as me but I'm fwd. I really hope this isn't the norm with these turbos and you figure out what's holding it back.

Cox Abele · Feb 25, 2015

98yctuner said:
Do you have 1g cas? If so, try advancing the timing a bit and go from there. Same situation happened to me a while back in my gst and I advanced my timing on the cas and BAM it really woke the car up.

I have a 2gb cas. Timing would have been dialed in within the tune while on the dyno.

It could be spring age, but the car is fairly solid otherwise. It can't hurt to install some new springs, but there is no indication other than their unknown milage that they are worn. I'm not going to rule the springs out and I should upgrade anyway.

I'm still open to suggestions.

lasthope05 · Feb 25, 2015

The power to be seems about right for an auto awd car @20 psi. That in itself is going to suck a lot of power. While the trap speed is kind of low it doesnt seem too far off. From what I've seen in the autos they dont run as fast as the 5 speed guys but they are quicker when comparing e.t. Do you have any logs of the pulls you can post up?

bastarddsm · Feb 25, 2015

a worn stock spring can be down to 50-60lbs on the seat, you can easitly generate enough drive pressure to blow the exhaust valves open.

Cox Abele · Feb 25, 2015

I'm reading up on springs and in the strictest position of bench racing, the theory may have value. I don't have the tools to measure valve height, and if I'm going to pull the valves to measure seat pressure (which I also don't have tools for), I may as well have a set of aftermarket springs to slip in.

The head has been machined/rebuilt. Exactly how much material or what has been done, I do not know. Deck height is unknown. How many times the valve seats have been cut is unknown. I don't know if new springs had been installed or the old ones reused. Worse case scenario; tired valve springs have been used unshimmed in a head that's had a valve job. Float could be a likely issue!

But let's keep talking.

Let me look at my tuning laptop and I'll see if there are still logs from the dyno session. I'll provide more info in a few minutes.

bastarddsm · Feb 25, 2015

There is no bench racing in this. Well used stock springs down in the 50-60lbs range at seat pressure. They start at 66lbs new. An exhaust valve has close to 1sq in of area. That means 60lbs differential across the valve and it opens. Stock frame turbos can easily exceed average 2:1 drive:boost pressures, and the peak exhaust can be 2-3 times the average value. Couple that with the fact that the cylinder pressure is below boost at EVC and you got yourself open exhaust valves.

Read kigglys post about dynamic port pressures. This is not a new phenomenon.

Cox Abele · Feb 25, 2015

bastarddsm, I should have clarified. I wasn't doubting the theory, but I was hypothesizing (bench racing) on why my particular setup could potentially be hanging it's valves open beyond the principles of tired springs. Simply, cut valve seats will have further detrimental effects on spring pressure of an already questionable valve spring.

I'll definitely get to reading up though, so thank you!

I can't really give logs since I don't see what the final log was for each tune for comparison.

Got out my tuning laptop and look as some logs as a general, along with the dyno graphs, and compare the Jestr tune to the Moore tune. I can't tell what the last log was with the Moore tune, but I'm seeing a huge differences between the tuners and their tunes.

Mustang dyno, Jestr Tune, previous:
325 whp @ ~6100 rpm, ~15-16* timing, 11.9 afr

Dyno Jet, Moore Tune, current:
284 whp @ ~6850rpm, 8* timing, 11.3 afr

The Jestr tune, across the board, has a more aggressive timing map along with leaner AFR. While the Moore tune is safe, I feel like there would be considerably more room to grow. Some of my current low timing/rich AFR may be an effort to spool the turbo given the WG issues I was having on the dyno. The mechanical cam timing being off would make up for the nearly 7* difference in timing maps provided the intake came was retarded. That would also explain the nearly equal torque and hp. Peak HP RPM of the jestr tune is also fairly low. Some of that can also be equated to the 272s.

lasthope05 · Feb 25, 2015

That last tune looks very conservative compared to the first and could be adding to your loss of power and top end. Double check mechanical timing and increase your ramp rate on the top end. I didnt see what fuel you were running, but depending on type you might want to richen it up a bit more for street duty.

Cox Abele · Feb 25, 2015

FWIW, I have a 2g Cam angle sensor, so there isn't any adjustment that I can do for base timing. Both runs were on 93 pump.

lasthope05 · Feb 25, 2015

Check mechanical timing marks, not base timing, as you said the exhaust might be off a tooth. Increase your ignition timing all the way back up till you knock and back off a degree or two.

As for afr's on pump, 11.3 works, but I like it a little bit richer(10.8) for street duty and doing back to back pulls. The added fuel helps keeps things cool and some knock at bay, but anything in the high 10's low 11's will work.

The huge differences in tuning styles is one of the reasons your not noticing much gain. The high timing/very lean afr was a high strung tune vs the low timing/avg afr's.

If you have access to the link forums run through the fastest times list and look at the people running auto and small turbos. You'll notice people running decent times with very slow trap speeds so I wouldnt worry too much about it. You just need a proper tune.

Cox Abele · Feb 25, 2015

Mechanical timing is on. I suspect I was off a tooth on the first dyno session. When I went back and looked at pictures, I have reason to believe one of the cams may have been off a tooth on the original setup. The high-torque and almost ~7* of timing between the two tunes suggests that on the initial timing belt install, the intake cam was retarded. Had the intake cam been installed correctly before the first tune, chances are the timing maps between both tunes would have been similar.

When I installed the 272s, I used a Jay-Racing gear holder, so mechanical timing is back where it should be, neither advanced or retarded on either cam. After that is when I hit the dyno the second time.

Using EcuFlash/EvoScan, I don't have access to the ECMTuning page.

lasthope05 · Feb 25, 2015

7* of timing between the two is a huge difference and one cam being off a tooth doesnt account for the other cam still being in the correct position. The car would run like crap if timing jumped.

I.E. Intake cam retarded 7* (-7) while the exhaust cam is at 0. Ignition timing is added to both simultaneously, not just one or the other. So adding an additional +7 degrees brings the base setting of the cams now to Intake (0*) and Exhaust (+7*)

This is why you make sure mechanical timing is perfect.

iceguru1114 · Feb 26, 2015

I spent several years in a test cell in college. Time and time again (no pun intended) ignition timing proved to be the single most important factor in tuning an engine. If you're not near mean best torque timing OR knock limited spark advance, there's power being left on the table. Btw, assuming your timing is correct (which it seems it might not be) 8 deg advance is waaaaaaaaaay conservative. That's the kind of timing you typically see for off-idle conditions.

Archer Fabrications · Feb 26, 2015

Well first of all you went from a 5 speed fwd (higher reading due to weight, and manuals read higher than autos)
To a heavier awd auto, which read lower. Same turbo basically... It is odd that the mustang read higher than the dyno jet but that could be a whole other list of things specificaly for dyno..I'm not surprised.
This tired old valve spring thing however could be true for me as well.

counti41 · Feb 27, 2015

youre not pushing the turbo hard enough. or at least youre below its efficency range. it gets more efficent at moving air with more boost and rpm which you lack. that turbine and compressor setup is for a car that is gonna be in the 7.5-8k range and over 25psi. then you should see some close to if not more than 400whp numbers. make sure your build and your tune can take it first.

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What could be wrong? Not making the power I thought I would.

Cox Abele

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