GT2871R Dyno results?

[sli240sx]

Whats up everyone, just dyno my car on a mustang dyno the other day and I didn't get what I expected. I have a full built motor with CP pistons 8.5 to 1 87mm, BC rods, HKS 264 step 2 cams, Greddy intake manifold, 70mm throatle, Ferrea oversized valves and springs and retainers, Tomei exhaust manifold, Greddy elbow, ES engineering cat-delete down pipe, HKS High power, and a GT2871R .64 ar. I was expecting at least 350whp but I only was able to reach 318whp. I have a Power FC controlling the fuel with 740cc injectors. The power also starts dying at around 6400 rpm which suck. I'm running 19.5 psi and hitting it at 4000 rpm which is not too bad. The tuner said it might be the sparks, that they are too cold or not gapped right. I think I have some decent spart plugs I have NGK iridium plugs gapped at .030. He also said the cam timing is off. I was wondering if I could be due to the VTC system that is still connected. Also my hydraulic lifters are also making some loud valve chatter. Would that cause a power loss? If someone could give me some ideas I would appreciate it.

[kingtal0n]

lol i just re read this and i see you have the .64 your only missing about 30 horsepower. you can find that almost ANYWHERE. For starters I would say reduce the boost pressure to 18PSI. next try a NEW set of plugs iridium (unless yours were new at the dyno) iridium plugs are good for diagnosing the problem but not actually using. Likely your tune is not where it should be, not because the tune itself sucks but because the engine isnt running where the computer thinks it is.

I would try some brand new iridiums on the dyno right after a pull on the old plugs and check the difference. it will take $32 and 10 minutes to do this and it can usually save alot of headache.

obviously first check for a boost leak, a small one can account for 30 horsepower.

if VTC is connected your power FC has control over when it comes off. VTC is on at low RPM for increase torque/response, then it comes off to retard the intake cam and allow for a later cylinder fill event which is conducive to filling the cylinders are high RPM when the incoming column of air is more substantial and continues moving even when the piston reverses direction, assuming the valve is still open.

You can run the engine without VTC by just changing the number in the PFC and see how it does and yes you might gain or lose 30 horsepower just with that alone.

besides leaks, timing, fuel, a missing 30 horsepower can be hidden in MANY places. Like a restrictive air filter.

honestly 320 is still pretty good i would turn the boost down to 15PSI and it will still probably make 320 horsepower, the problem isnt likely to be boost related, that turbo is pretty "small" meaning the sr20 with the mods you have is pretty exhausting to the compressor especially when coupled with the exhaust gas pressures of the .64 turbine, if you turn it to 15PSI and it hits 310-320 horsepower then keep putting in 93 octane and enjoy it like that if you dont see something simple wrong.

[liquid_cool]

for your spark issue ..mod the ingnition system...MSD 6AL comes to mind..of a MSD with a built in timing retard feature..im no turbo guy but you can see improvements in your build with a good ignition system...looks like its the last part of your build man..good luck

[maryjane]

seeing the 6al is ment for a single coil pack set up, not a sr set up

[Sileighty_85]

Split Fire Ignition

crank up the boost.

My husband is pushing 1.5 bar on stock cams and I/M and he put down 363whp on a mustang dyno

although with cams and I/M you should have made a bit more

[kingtal0n]

he doesnt have to crank up the boost if anything he needs to lower it. If The turbo is running out of breath even at 15PSI its not going to make anymore power trying to keep up with 19 or 22 or 25 psi. the compressor doesnt magically flow more just because boost is higher.

more boost will do one thing though: it will increase your tire shredding mid-range torque. My favorite GT2871R setting is boost dialed like this:

1st gear 12PSI2nd+22PSI @ <4000RPM18PSI @ 5000RPM15PSI @ 6000+

22-25PSI the compressor can support @ 4000~RPM plenty of cool air and plenty of torque to blow the tires off withyou run 93 octane with about 5-7* of timing total and 11.2:1 A/F ratio its SAFE

its f***ing golden

[sli240sx]

Yeah when I lower the boost I lose power so 19 is about its max.

what should be the timing on my car? I think its off and thats why I'm lossing power at the top end. Is the stock timing wrong? should I have it a little advanced? I didn't install any cam gears so should I get some.

I was looking at my power FC to see if I could check out the air temp, could I install an air temp sensor and have the power fc read it? I has the option for it but its not working and I don't have the D-jetro.

I changed the spark for some one step colder plugs instead of the 2 step ones that I had in there origanaly. They were also brand new when I went to the dyno.

You think I need a spark a HKS twin spark? I would think I needed that until I was making some serious power.

I was thinking of swaping out the lifters for some solid ones but some one already discouraged me on doing that. I don't know why I have such valve noise. Maybe my hydraulics lashers are bad. I should probably change them. Its just so expensive compared to a set of soild ones, and aren't solid one's better?

[kingtal0n]

Yeah when I lower the boost I lose power so 19 is about its max.

what should be the timing on my car? I think its off and thats why I'm lossing power at the top end. Is the stock timing wrong? should I have it a little advanced? I didn't install any cam gears so should I get some.

I was looking at my power FC to see if I could check out the air temp, could I install an air temp sensor and have the power fc read it? I has the option for it but its not working and I don't have the D-jetro.

I changed the spark for some one step colder plugs instead of the 2 step ones that I had in there origanaly. They were also brand new when I went to the dyno.

You think I need a spark a HKS twin spark? I would think I needed that until I was making some serious power.

I was thinking of swaping out the lifters for some solid ones but some one already discouraged me on doing that. I don't know why I have such valve noise. Maybe my hydraulics lashers are bad. I should probably change them. Its just so expensive compared to a set of soild ones, and aren't solid one's better?

Your primary goal is engine longevity, followed by power. When I tell you to turn the boost down, its not because im trying to ruin your power, im trying to save your engine. more boost does not always equal more power, and even if it does, it doesnt always mean more power safely.

Can you upload me your timing map or make an excel file for it Since you have an AFM PFC you cannot run an intake sensor, but its ok, because you have something better, the AFM is more accurate for making stabs at lb/min airflow than doing the old PV=nrT stuff (air temp + pressure to get volume)

Your maf is the key to understanding what your engine is doing. Do you have the data-logit box for the PFC? That would make this diagnosis very easy, you could record a WOT run for me and send it to me and I can pick it apart from here.

As to your top end racket, Im assuming its clacking away at idle like theres a loose set of bbs under the valve cover. DID you installed the lifters and if so did you bleed them in oil manually before installation. at this point if your realizing no you didnt do this, then go outside take your lifters out and bleed them in a cup of oil, the noise is likely due to air being trapped inside each one.

And no you dont need ignition aplifiers the factory ignition is fine until it gets blown out and even then you can decrease the gap to a point without losing serious fuel economy. And thats what its all about at the end of the day, portion of combustion started under high resistance conditions and is it enough to allow for critical timing. you see when a spark is "weak" that is, combustion is happening because the spark is there but its "BARELLY" there, your timing profile gets all f***ed up. With a weak spark you need to time the engine far advanced, to allow combustion to propagate in time for the cylinder down event. poor/weak spark will cause an engine to seemingly run fine, but upon closer inspection, timing is not optimal, and it is generally over-fueled and under powered. This could be your condition and yes buying a twin spark might put it to rest. But the point is, you shouldnt NEED to buy an accessory, the factory ignition SHOULD be FINE where you are at.... perhaps your coil packs are just old.

[sli240sx]

Can you upload me your timing map or make an excel file for it Since you have an AFM PFC you cannot run an intake sensor, but its ok, because you have something better, the AFM is more accurate for making stabs at lb/min airflow than doing the old PV=nrT stuff (air temp + pressure to get volume)

Your maf is the key to understanding what your engine is doing. Do you have the data-logit box for the PFC? That would make this diagnosis very easy, you could record a WOT run for me and send it to me and I can pick it apart from here.

.

Ok i'll try to post a timing map of my set up. Just to get it strait the timing map is that square chart right?

As far as the data-logit box I don't know what this is. what is a WOT run?

When I did the rebuild I had the shop put in the hydr lifters along with everything else. I asked them if they bleed the lifters and they said they did. I'm really thinking about putting is some BLE soild lifters that way I could see if that would help any and also so they can reset the timing on the motor. I have the step 2 cams so they are good for solid or hydr.

[sli240sx]

Ign map

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20L01 25 28 32 40 40 40 39 39 39 39 39 41 42 43 43 43 43 43 43 43L02 25 28 32 40 40 40 39 39 39 39 39 41 42 43 43 43 43 43 43 43L03 25 27 31 37 39 37 37 37 37 37 37 39 40 41 41 41 41 41 41 41L04 22 26 30 35 37 36 36 36 36 37 37 38 39 40 40 40 40 40 40 40L05 20 20 29 33 34 33 33 33 33 37 36 37 38 39 39 39 39 39 39 39L06 18 24 27 31 32 30 30 30 31 34 36 37 37 38 38 38 38 38 38 38L07 16 22 26 30 32 30 29 28 28 30 34 35 36 37 37 37 37 37 37 37L08 12 19 25 29 31 29 28 26 27 28 30 33 35 36 36 36 36 36 36 36L09 11 16 22 28 30 28 26 24 25 26 28 32 34 33 34 34 34 34 34 34L10 09 13 16 24 27 26 23 23 23 24 27 30 31 31 32 32 32 32 32 32L11 08 13 14 19 23 24 22 23 23 23 25 27 27 28 29 30 31 31 31 31L12 08 13 14 15 17 20 20 21 21 21 25 24 26 26 28 28 30 30 30 30L13 07 12 14 15 13 17 19 20 19 18 23 23 23 23 25 26 28 28 28 28L14 06 11 14 15 11 14 14 17 15 16 18 19 22 22 25 25 26 26 26 26L15 05 11 14 15 11 13 12 15 13 15 16 17 19 20 21 21 23 23 23 23L16 08 14 17 18 14 15 15 18 16 16 16 16 20 19 21 21 22 22 22 22L17 08 14 17 18 14 15 14 17 16 16 15 16 19 19 21 21 22 22 22 22L18 08 14 17 18 14 15 14 17 15 15 14 16 14 18 20 20 21 21 21 21L19 08 14 17 18 14 13 14 16 15 14 14 16 18 18 20 20 21 21 21 21L20 08 14 17 18 14 15 14 15 15 14 13 16 18 18 19 20 20 20 20 20

[dbrass240]

i believe its your timing - i used to have same setup and put down almost 385whp...recheck your timinig - i was runnig a bit retarded and i couldnt really tell but as soon as it was dialed in correctly it was like night and day!

i dont remember gapping my plugs at all and i used iridiums...also - any boost leaks - it only takes a small unseen leak to cause a slight power loss. You should be in the 350-370+whp range

[dbrass240]

also those cams really dont open til a lot later -need to be tuned for more top end air flow. . .btw, i was runnin about 20psi on my runs and had a megan manifold, not balla tomei...

also - didnt hear you mention anything about front mount? what setup you runnin up front?

[sli240sx]

I do have a 3 inch thick intercooler. yeah I'm think its my timing. I need to check it out. I really don't know how to set that up so I have to rely on a shop to do it.

[sli240sx]

Inj map N1N2N3N4N5N6N7N8N9N10N11N12N13N14N15N16N17N18N19N20L01 121 122 125 107 107 107 107 107 107 107 107 130 130 128 130 130 130 130 130 130L02 127 123 127 107 107 107 107 107 107 107 107 130 130 128 130 130 130 130 130 130L03 118 123 127 107 107 107 107 107 107 107 107 127 127 129 130 132 132 132 132 132L04 118 123 127 107 107 107 107 107 107 107 107 127 126 125 132 137 137 137 137 137L05 118 123 127 114 102 102 102 102 102 102 116 116 116 121 125 134 134 134 134 134L06 108 105 108 109 102 102 102 102 102 102 116 116 123 123 128 139 139 139 139 139L07 107 105 108 109 108 105 105 105 105 105 105 111 115 117 123 132 132 132 132 132L08 108 100 107 107 105 103 105 105 105 105 112 116 126 133 138 138 138 138 138 138L09 110 100 107 105 109 109 109 105 107 107 116 124 130 134 140 144 144 144 144 144L10 106 95 109 106 107 106 105 105 108 113 125 128 132 135 142 148 149 148 148 148L11 104 96 107 107 104 104 102 106 111 117 129 133 135 136 141 144 145 144 144 144L12 112 108 108 108 107 106 104 119 126 125 132 137 139 142 144 144 145 144 144 144L13 113 109 108 108 110 115 109 129 141 133 139 141 127 131 131 131 132 133 133 133L14 115 111 110 110 115 120 125 134 145 143 147 148 131 132 132 130 130 131 131 131L15 116 112 112 112 119 125 128 138 149 147 149 149 130 131 131 128 128 128 128 128L16 116 112 112 112 119 125 128 138 149 149 149 149 131 131 131 128 128 128 128 128L17 116 112 112 112 119 125 128 138 149 149 149 149 131 131 131 128 128 128 128 128L18 116 112 112 112 119 125 128 138 149 149 149 149 131 131 131 128 128 128 128 128L19 116 112 112 112 119 125 128 138 149 149 149 149 131 131 131 128 128 128 128 128L20 116 112 112 112 119 125 128 138 149 149 149 149 131 131 131 128 128 128 128 128

[sli240sx]

Does anyone have a good place to tune a Power FC down in South Florida?

[sli240sx]

i believe its your timing - i used to have same setup and put down almost 385whp...recheck your timinig - i was runnig a bit retarded and i couldnt really tell but as soon as it was dialed in correctly it was like night and day!

If I want to retard the timing do I need adjustible cam sprockets?

[dbrass240]

i used to have hks cam gears but they're are only used to FINELY tune your setup. It looks as if your base timing is off.

Also, have you checked compression on your cylinders? Something else just doesnt seem right....

Also, when you're in the car . . . does it seem to pull hard at only a small portion of the power range? If so, then its your timing . . . i had the same problem after i rebulit my motor and had a shop do the timing . . . I had to redo it but got it perfect after piddling with it for hours.

[kingtal0n]

your timing is too advanced for pump gas

it should be more like 8* around peak torque and no more than 14* by redline

8-10-12 is a good standard

8* from 4-6k10* 6-7k11-12* by 8,000RPM

WHen your torque starts to fall, thats when the advance starts to come up from 8*. You leave it at 8* everywhere torque is flat. and EGT gauge would be nice to look at also. If you try 8* and the manifold turns red then either your computer is not synched to the engine or there is another problem (possible cam timing related)

[sli240sx]

ok I'll try that. I definitely think its timing. I'm going to the shop next week to put in the BLE solid lifters, fix timing, check for boost leaks, and fix the exhaust turbo elbow leak.

[kingtal0n]

Before you try solid lifters why dont you use a feeler gauge to check the distance between the rocker arm and the shim after running the engine for a bit. If its unusually large clearance then all you need is a new set of shims.

[codyace]

Flame suit on, but find a better tuner. There are 28RS cars making considerable more power than your car is now, and they have an even smaller compressor side.

There are plenty of people making 350-400 on rom tunes from Enthalpy or Jim Wolf.

Aside from that,

-Check your base timing, as well as cam timing.... Seems like every car I ever check is off....on one or the other.

-Perhaps the machine shop fubared the valve job?

-What are your AFRs on the dyno? Fuel Pressure?

- I run a .022 gap on my car, even with an ignition amp. We also do this on FWD sentras. Never any issues, and no loss in performance....

As you said, that car should be making more power than it is...it's obviously something simple, as you have a good parts list.

[kingtal0n]

How are you getting those maps? how are you tuning the ecu? The data-logit is a black box you buy for about $350 it connects the laptop to the power FC and it has analog inputs on one side.

I assumed you had one, since using the commander is untolerable, but i suppose its not so bad if you are only playing with the timing. You verified the timing right? at 3000RPM the timing gun says what the computer says right?
Modified by kingtal0n at 8:49 PM 8/23/2009

[sli240sx]

Hey guys just Dynoed my car and made 415whp and 360 torq at 19.8psi!!! Everything was fine really. The problem was the CAS was off. once they fixed that then the power went up, then retune. Im very happy with those numbers. thanks for all the great information.