Went to dyno, but didn't go well... power loss from HKS camshafts!

[JDMSIL80]

Just came back after from dyno to find out how much power I would gained from the addition of HKS 264/272 camshaft and SARD FPR.

The last time (2 months agao)I made the baseline of 289whp @ 18psi with following mods:

Bone stock motorGarrett GT28R444cc GT-R injectorsHorsham stage 3 chip Blitz I-D color EBCFET coil packXS Power FMICXS Power turbo manifoldXS Power down pipeMegan Racing exhaustHKS SSQV recirculatedHKS Power filterZ32 MAFWalboro 255 fuel pump

But to my surprise, today I suffered HUGE power loss throughout the power band! I only made around 257whp at the end.

The left pic is what I made last time, the right pic is what I made today. Compare the numbers in the same rev interval and you'll see how much I loss:

This is strange because I was expecting to make more power with the cams, but instead I am losing power. The boost is now spooling even later than before, and my high end power isn't holding as expected.

So now I'm trying to narrow down to few factors:

Do these HKS cams require extensive tunning to make power?? I am running a Horsham Stage 3 chip that was made for internally stock motor, but my A/F ratio is still consistent even with the cams. I bet there's some room for tunning that can be done, but I'm not convinced to be losing major power all the way just by switching the cams.

I do not have cam gears, so the cams were left at 0, 0.

My A/F ratio in the top end is 10.7 today vs 11.5 from last time, so that might contribute to some high end power loss.

Although the outside temperature is very hot today (at least 15 degrees celcius more than last dyno). It was a good 45mins drive on highway from home to dyno, so the car was boiling hot when I got there. We did let the car cool down a bit and put fans infront of the intercooler. As the temperature sensor read, the intake temperature shows only 2 degrees hotter compared to last dyno. So that might contribute to some power loss as well, but shouldn't be too much.

I'm thinking if the plugs can be the reason too. My hose clamp slipped out from the cold pipe hose joint the night before, and I was driving with boost leak so the A/F was very rich (10s) for at least 20mins before I made it home to fix it. I was thinking if that might be enough to foul the copper plugs already, so that might also played an effect.

Need you guys to help me out on this one, thanks!


Modified by JDMSIL80 at 10:26 PM 7/24/2006

[boost_boy]

Those cams aren't that eccentric and your losses are definitely not just the cams. The bigger cam on the exhaust side will hurt you down low, but it shouldn't be that significant on the top end. I can't tell you to go back and try it again because you say you live 45mins away from the dyno and that's just not going to be efficient for you. Let me ask you this, when you installed the cams, did you reset your computer or just left the batter hooked-up? When you did the last dyno run, was the ecu chipped with that chip or stock? The plugs can also be a factor, but we'll cross that path later. Unfortunately, it sounds like you're going to need some tuning, but I'll wait for your answers to the questions I asked.

Dee

[r32line]

Yeah like boost boy pointed out, reset your ecu after you change things like that, that way the ECU can accomodate the changes quicker. Id say a tune may be the best way to take full advantage of the mods.

[tyrannix]

did you just do one dyno run? or was there any tuning involved that day?

CJ

[panapower]

Can one just throw in cams in an engine and make power out of them without dialing them in!?!?

[JDMSIL80]

During the installation of the camshafts, I didn't disconnect the battery. But I did reset the ecu (several times indeed) after putting in the camshafts. From the driving impression right after I put in the cams, I felt a slight loss in low end but gained a huge power from mid-range to high end.

In the last dyno I ran two months ago which I made 289whp, I was running the same Horsham Stage 3 chip with stock ecu. Basically nothing was changed since the last dyno except the addition of HKS cams and Sard FPR. I have also replaced with a new Z32 MAF & O2 sensor, that's all.

Unfortunately I couldn't get a printout of the dyno graphs because some software issue with the shop. By comparison to the last dyno, my new graph is way below of what I made last time. I started lossing power down low from 5whp all the way to the top by 40whp, both runs were at 18psi.

The curve of the graph looks different too. The last dyno curve was curving upwards down low and gradually flattens out at the very top. The new dyno curve is bascially slanted straight from the down low, then boost peak in the midrange, but comes back down again in the top end. This is strange because I thought these cams would hold and make power up top.

Something is definitely screwy here. But honestly if I didn't visit the dyno, I wouldn't know or able to tell something's up with the power.

Those cams aren't that eccentric and your losses are definitely not just the cams. The bigger cam on the exhaust side will hurt you down low, but it shouldn't be that significant on the top end. I can't tell you to go back and try it again because you say you live 45mins away from the dyno and that's just not going to be efficient for you. Let me ask you this, when you installed the cams, did you reset your computer or just left the batter hooked-up? When you did the last dyno run, was the ecu chipped with that chip or stock? The plugs can also be a factor, but we'll cross that path later. Unfortunately, it sounds like you're going to need some tuning, but I'll wait for your answers to the questions I asked.

Dee

[JDMSIL80]

I don't mind doing a full tune to make the most of the mods. But first I wanted to figure the problem first because putting in more money.

Yeah like boost boy pointed out, reset your ecu after you change things like that, that way the ECU can accomodate the changes quicker. Id say a tune may be the best way to take full advantage of the mods.

[boost_boy]

I don't mind doing a full tune to make the most of the mods. But first I wanted to figure the problem first because putting in more money.

Did you check and re-check cam timing, then ignition timing, then ignition timing under load? The reason I ask this is, not saying it's true, but possibly the cam timing is off and possibly causing high egts or timing is too advance and causing the engine to detonate which causes the knock sensor to pull back timing to safe level. I'm just throwing a few things out there because it's not the cams that are causing your power loss. Dude, I would check and double check everything possible before you start making conclusions. I'm pretty sure you'll be able to safely figure this stuff out.

Dee

[JDMSIL80]

I don't believe the cams would make me lose power either.

However, people from SXOC & Freshalloy who responded to my problem are saying the my camshafts are way too aggressive for my GT28R. Which my turbo will run out of breathe long before the camshafts make power. They said I should change back to stock or keep 256's for the turbo size. Do you agree on this statement?

All i know is that my timing is set at 15* BTDC when my mechanic put in the camshafts. What should the cam timing and ignition timing be with these camshafts? Please advise.

Did you check and re-check cam timing, then ignition timing, then ignition timing under load? The reason I ask this is, not saying it's true, but possibly the cam timing is off and possibly causing high egts or timing is too advance and causing the engine to detonate which causes the knock sensor to pull back timing to safe level. I'm just throwing a few things out there because it's not the cams that are causing your power loss. Dude, I would check and double check everything possible before you start making conclusions. I'm pretty sure you'll be able to safely figure this stuff out.

Dee

Modified by JDMSIL80 at 5:03 PM 7/25/2006

[boost_boy]

I don't believe the cams would make me lose power either.

However, people from SXOC & Freshalloy who responded to my problem are saying the my camshafts are way too aggressive for my GT28R. Which my turbo will run out of breathe long before the camshafts make power. They said I should change back to stock or keep 256's for the turbo size. Do you agree on this statement?

All i know is that my timing is set at 15* BTDC when my mechanic put in the camshafts. What should the cam timing and ignition timing be with these camshafts? Please advise.

Modified by JDMSIL80 at 5:03 PM 7/25/2006

Everyone is entitled to their opinions on the matter, but the bottom line is that you're not happy with your last dyno outting and you need answers. Your camshaft set-up in my honest opinion is not too aggressive at all for your turbo configurations. I would even consider the ecu's chip. I'm pretty sure Horsham is established at doing what they do, but maybe that chip is preventing the ecu from fully responding to your upgrades. It so many variables to consider that it's not even funny or can be something as simple as increasing the fuel pressure.

I'm like you, I'm firing in the dark at this issue, but the camshaft set-up you have is the exact same one I'm using. And though I haven't gone to the dyno yet, I have a little more flexibility with the standalone I'm using. Baseline timing should be at 15* BTDC. I don't know where the Horsham chip puts your timing, but if this the same ecu you've used in the past, it could be a matter of getting some kind of piggy back for some additional tuning because adding camshafts will require you to do some tuning.

Dee

[JDMSIL80]

Horsham recommends 15* BTDC, I'm going to email him and see what he says about the situation. Maybe he can get me a custom chip to accomdate the camshafts, it might be cheaper this way than getting a piggyback and tune from there.

Everyone is entitled to their opinions on the matter, but the bottom line is that you're not happy with your last dyno outting and you need answers. Your camshaft set-up in my honest opinion is not too aggressive at all for your turbo configurations. I would even consider the ecu's chip. I'm pretty sure Horsham is established at doing what they do, but maybe that chip is preventing the ecu from fully responding to your upgrades. It so many variables to consider that it's not even funny or can be something as simple as increasing the fuel pressure.

I'm like you, I'm firing in the dark at this issue, but the camshaft set-up you have is the exact same one I'm using. And though I haven't gone to the dyno yet, I have a little more flexibility with the standalone I'm using. Baseline timing should be at 15* BTDC. I don't know where the Horsham chip puts your timing, but if this the same ecu you've used in the past, it could be a matter of getting some kind of piggy back for some additional tuning because adding camshafts will require you to do some tuning.

Dee

[JDMSIL80]

So I emailed Horsham and here's his response:

Hi I'd say that the duration of those cams is way to high. I'm running around 480whp and using 260/260 cams. I do not have any maps for those cams - ideally you need to get the car live mapped. If you want to save cash, I'd go back to standard cams and get the 40hp back. CheersJez ---------------------------------------------------------http://www.h-dev.co.uk - ECU upgrades and mappingNew Subaru ECU Upgrades coming soon: http://www.h-dev.co.uk/subaruSponsors of Team Falken GB Drift Team http://www.teamfalkengb.com

[Trigger]

well that wasnt much help was it...

[JDMSIL80]

I'm thinking if I should replace the exhaust camshaft with 264 instead and have less overlap. From what I heard so far, ppl are saying the 272 is way too aggressive for the turbo.

[boost_boy]

I'm thinking if I should replace the exhaust camshaft with 264 instead and have less overlap. From what I heard so far, ppl are saying the 272 is way too aggressive for the turbo.

That's crazy! The biggest thing I see is that you don't have the ability to manipulate your ecu to accomodate such camshafts. I say again, those camshafts aren't that crazy. I have a set of camshafts in my garage (276* w/11.5mm lift and 268* with an 11.35mm lift) that I consider to be wicked. If you feel the camshafts are hurting you and you don't want to change your electronics, put your stockers back in and call it a day. With upgrades comes extra modification and that's the only way you're going to advance your power significantly. If you liked your performance before, put it back to the way it was and take it back to the dyno to see if things are back to normal.

Dee

[Trigger]

i say put a piggy back system on so you can make the changes that need to be made.. its not like you have to buy it right now, your car is running fine right. just save the money up for a piggy back and then you will beable to get all the power that those cams are supposed to make...atleast thats what i would do.

[JDMSIL80]

What size of turbo are you running? From the majority said it is the turbo size I have thats not compatiable with the camshafts. Infact I did notice during the dyno runs, you can hear the air from turbo push the inlet charge straight back to the exhaust from the overlap. It took longer for the turbo to spool up and it didn't sustained the boost as well as before with the stock cams.

Here are some responses from other boards:

http://www.sxoc.co.uk/vbb/show...62296

That's crazy! The biggest thing I see is that you don't have the ability to manipulate your ecu to accomodate such camshafts. I say again, those camshafts aren't that crazy. I have a set of camshafts in my garage (276* w/11.5mm lift and 268* with an 11.35mm lift) that I consider to be wicked. If you feel the camshafts are hurting you and you don't want to change your electronics, put your stockers back in and call it a day. With upgrades comes extra modification and that's the only way you're going to advance your power significantly. If you liked your performance before, put it back to the way it was and take it back to the dyno to see if things are back to normal.

Dee

[boost_boy]

I run a T3/T04E 60-1, but with a few tricks to make it a frankenstein candidate. For the record, my back housing is a .48..........

Dee

[JDMSIL80]

Is your turbo bigger than my GT28R? How much rev is it good up to?

I'm gonna put the stock exhaust (248) cams back in tomorrow and see if it improves.

But as a general rule, would a 264/248 combination work well with GT28R?

Thanks!

I run a T3/T04E 60-1, but with a few tricks to make it a frankenstein candidate. For the record, my back housing is a .48..........

Dee

Modified by JDMSIL80 at 3:13 PM 7/28/2006

[Kouks]

the bigger intake will(should give you) generally improve midrange.

His turbo is bigger than yours yes. I would say with his smaller exhaust housing catered to the ca, it dies at 7100rpm. Guesstimate on size of the turbo and 272 cams.

i currently have 256/248 cams in my ca. Should feel great with my t25g, i think you should consider a 264/264 or even 264/256 in your car. It is street driven and you want some low/mid power.

try out different combinations and see what works for you. I woudnt run 272 cams in my car unless I had a gt2871 in my car or bigger.

[OmarM]

Who installed the cams, I think they were installed wrong is what I getting at, or your motor has super low compression. Even if its not tuned properly, you would still notice a difference if cams were set at O degrees. On the dyno if cams were too aggressive you might worse case lean out. But if A/Fs are fine, than something is worng with cam timing or you CAS is bad.

[OmarM]

And looking at your dyno sheets you made 271 peak with the new cams at 5816rpms. looks like your running pretty rich up top. I would try to lean out to about 11.8 to 12.1 a/fs might help power.

[JDMSIL80]

The 271 peak is just a boost spike, realistically i made around 250whp.

Leaning out on top should help a bit, but still wouldn't bring be back to the power I used to have.

The camshafts were installed by a mechanic, it should be pretty straight forward and nothing could possibly went wrong. The car doesn't drive funny or strange in anyway, if I didn't go to the dyno I probably wouldn't know I lost power.

From what I found so far from other ppl, my GT28R is too small to accomadate 272 exhaust camshaft. I would need at least a GT2871R for these high duration cam.

I'm gonna put the stock exhaust cam back in, leaving the 264 intake cam and see what happens. Will keep you guys posted.

And looking at your dyno sheets you made 271 peak with the new cams at 5816rpms. looks like your running pretty rich up top. I would try to lean out to about 11.8 to 12.1 a/fs might help power.

[niscort]

just some observations...

*the dyno operator is having software issues.*your speed vs rpm is 100rpm out by 6500 on both printouts*your running a mail order chip for a euro ecu.the base timing for jap spec engines is 10deg not 15. also what is controlling your intake butterflys? * you installed a FPR, yet no mention if the base fuel pressure was set? is it a 1:1 rate regulator?

seriously your car needs real tuning for the current setup, not more bolt on parts

[slownslurious]

I have a set of HKS 256/265 8.5's for $400 if you are interested, they may help fix your problem, you aren't using the power band those 272's are providing right now.

[JDMSIL80]

Do you guys think a 264 exhaust camshaft would be compatible with my setup? Or just settle with stock exhaust camshaft?

I have both camshaft sitting around, just thinking which one to put in. Either way I have pay labour to install.

Thanks!

[boost_boy]

Do you guys think a 264 exhaust camshaft would be compatible with my setup? Or just settle with stock exhaust camshaft?

I have both camshaft sitting around, just thinking which one to put in. Either way I have pay labour to install.

Thanks!

Realistically JDM, what kind of power are you looking for? You can get over 300whp with the stock engine, period. The 264s on both sides are excellent too as I once ran this set-up and got excellent performance out of them. Good idle, good power and overall good on power throughout the rpm band. Changing them around would be your choice, especially if the stock ones gave you what you wanted.

Dee

[tyrannix]

Dee, whats that hanging off your IC? or is that an illusion of somethign on the ground?

CJ

[boost_boy]

Dee, whats that hanging off your IC? or is that an illusion of somethign on the ground?

CJ

Must be the car's shadow because there is not enough room left to hang anything from the intercooler.

Dee

[tyrannix]

this.