:::RHMT::: Real Home Made Turbo
General Category => Engine Management => Topic started by: danz on September 16, 2009, 08:36:59 PM
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i am going to be switching from a medium lift low overlap cam (bisi.......................) to a high lift high overlap cam (colt cam) on my holset A6.
when going from a low overlap medium lift cam, to a big ass NA cam, what can i expect in terms of detonation/possible timing
ie, with a bigger lift/higher overlap cam should i be looking to add, or remove timing from the maps. i assume with the bigger cam it will bleed off more pressure but i just donk know
figured i would ask the homies
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fucked up tits = no tech answers
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fucked up tits = no tech answers
good thing i didnt post pics of mine. ahahhaha
its not like you know anyways, SON!
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Why you getting rid of your Bisi cam?
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Because bisimoto is a fucking homsexual that doesn't know shit about cam design. At least not for turbo's.
I've tuned a an F22 bisi cam vs a 272 regrind and the 272 did MUCH better.
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Because bisimoto is a fucking homsexual that doesn't know shit about cam design. At least not for turbo's.
I've tuned a an F22 bisi cam vs a 272 regrind and the 272 did MUCH better.
i'd like to see you build one.
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Build a cam?
I can design one, if that's what you mean.
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The simple answer is just copy crower stuff
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ryan, the car wont carry torque for shit. i have a huge NA cam that i might as well try. i would go to speedfactory for a retune but its sooo late in the season its just not financially viable. ill go and visit james next season for a retune
we all know bisi has a small wanker...
how about timing? my plan is to turn down the boost a little, make some WOT passes listening for det and to take it from there. currently running 7.25-6.75 degrees at WOT/22psi according to ectune datalogs.
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Depends on the RPM's the motor/turbo are meant for. If you won't be revving much over 7k, then a hi overlap/lift cam will hurt you.
There's lots of other factors too, though.
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I've tuned a an F22 bisi cam vs a 272 regrind and the 272 did MUCH better.
really? have any dyno sheets?
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Listen to the Crower turbo cams beat the ground and tell me that overlap is bad. Turbo cars tend to like NA cams... and turbos also push any given cam's "sweet spot" higher into the RPM range than it exists in NA form. Being able to spin GSRs or ITRs to 9500 rpms with boost is a good example of this.
The caveat to all of this is that if you go super big on the cam then it *appears* to make the car spool later and be peakier. Given how no one apparently adjusts cam positions on the dyno with turbo Hondas, despite *all* D16 really requiring you do so, I'm half confident that a cam like the 59300 could be made to spool like stock and give good gains across the powerband. How big your Colt grind is, and how that shit will go down, I don't know.
Because bisimoto is a fucking homsexual that doesn't know shit about cam design. At least not for turbo's.
Yeah, not being able to break 280 whp on a built to the gills Y7 is disheartening. I'd suspect something else if that wasn't a common theme with other's cars.
My dude with the NA F23A1 went from 159 whp 151 wtq (post dyno) to 176 whp 170 wtq and power falling off hard at 6200 (street tuned to set AFRs, needed back on the dyno because the powerband had *shifted*) on a mild Bisi grind. So the guy does know what he's doing on some level, he just knows dick about boost.
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On some level. I've seen good shit with his NA cams, not so much on any of his turbo grinds.
and no, no butt dyno's. Most tunes I do hardly ever end up on the dyno. If they do, they're usually the NA type.
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a little more info on the setup, current powerband with the HE351CW Holset and the Bisi 1.22 grind is peat torque/boost at 5400rpm, and only taking it to 7800rpm. torque hits 266.6ftlb at 5400 and drops to 215ftlb by 7200 with the bisi cam im running now.
best mph so far is 118mph, best et 11.793. car weighs 2200 w/ me in it. ectune
head is stock except for a port match on the z6 intake manifold
jd, advertised specs for the cam, its branded as a tri-flow cam, one valve opens at a different time on intake to create swirl i assume
duration at .50, advance, valve lift primary: 198deg, 278deg, .391
duration at .50, advance, valve lift secondary: 193deg, 264deg, .381
duration at .50, advance, valve lift exh: 196deg, 267deg, .404
oh, cam retarded 2degrees on the dyno by james, it helped carry the torque a little but nothing to write home about
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Can you get a picture of the dyno graph?
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sure jd
i should have though about posting that pic in the OP before i opened this thread at work today... LOL
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I'd have retarded the cam a little more. A lot of guys don't like to with an un-clayed motor, but if you have a Vitara/stock length rod combo I wouldn't worry about it.
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8.5 SRP's in an D16A6, w/ A6 head.
this thing has a hard time pulling -20inhg as it is. hah
when i switch the cam, ill start with the same timing values i have now, and start to add some if i dont hear any det/see aluminum on the plugs
from everything ive read the bigger cam should bleed off pressure and allow me to run more timing as is.
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Idle vacuum is irrelevant. 2JZs with cams can idle -6 to -8 in/Hg, LS with 404s are usually -10 in/Hg. Crower 2 turbo -15 to -18 in/Hg. It's just the load you tune the idle at, nothing more.
Nothing's bleeding off, as IM pressure vs drive pressure ratio is about the same as a NA motor.
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I would have put some c16 in that bitch, and leaned on that holset a lot harder. ;D
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I would have put some c16 in that bitch, and leaned on that holset a lot harder. ;D
that is already at 24psi, kinda disappointing :'(. its either the head or the cam... going to try out a new cam and then swap to a Y8 head for next year
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I would have put some c16 in that bitch, and leaned on that holset a lot harder. ;D
...and then swap to a Y8 head for next year
I may have one of those available shortly, I just put the rod through the block of my DD. I still have to pull it apart and see if the head is any good, or if it was smashed.
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I'd stick to the z6 head and do some work to it, plus change the cam. valve job + some port massaging should be able to rev that bitch out.
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Dyno graph looks about like the first and last Bisi turbo grind I touched.
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What's the rest of the setup consist of?
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What's the rest of the setup consist of?
Big everything, made power to 8400rpm with the old stock cam.
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meant the op.
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There's nothing wrong with Z6 heads. Y8 heads are the worst head for forced induction unless you kill off the quench.
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What's the rest of the setup consist of?
Holset HE351CW
4inch downpipe to 3inch under axle exhaust, one reasonator
Splog manifold
28x9x2.75 FMIC
2.5inch cold side 2.25inch hot side charge piping
Z6 intake 60mm TB (Z6 intake matched to TB)
Stock port A6 head port matched only
Bisi springs and retainers (these i am 100% happy with)
SRP 8.5:1 pistons
Bisi 1.22 turbo cam w/ adjustable cam gear
i think thats just about it
oh, and boost held solid on the dyno, actually creeped up a little and the torque still fell off!
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Try more retard. 2 degrees isn't enough to get a factory cam back to stock position after a D's been decked, milled.
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So you're supposed to retard the cam after milling/decking to get it back to get the centerline at tdc?
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So you're supposed to retard the cam after milling/decking to get it back to get the centerline at tdc?
I retard my cam 2 deg. b/c I decked my block 0.020".
Y8 head on z6 block had to advance the cam 4.5 deg.
So my total cam advance was 2.5 deg.
Hope this helps. ;D
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So you're supposed to retard the cam after milling/decking to get it back to get the centerline at tdc?
Pretty much. B-series are thrown off, as well, but it's typically at or under a degree whereas D-series are always off 2+ degrees. With how the B-series is indifferent to cam timing when boosted it's not worth so much as looking at, unless you have early Prox cams that require you adjust them to even make the car idle.
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No I was just wondering because a friend and I were discussing it yesterday. He milled his f22a head .035 and is having issues even just idling and he said he had advanced 5 degrees with no luck. I thought it was retard, but I just wasn't sure.
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i installed the cam, left the timing the same and no detonation..
only did one pull, it was a 5th gear pull on the highway and i couldnt hear anything crazy
i also let out the MBC so its only hitting 15psi, but ill just ramp it up slowly and take it from there.
on a side note; the car pulls like -17inhg at idle. lol
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It's not too big of a cam then. My old 272 did about the same.
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ya its not too crazy at all but it feels pretty strong on only 15psi... almost as quick as the bisi at 20
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Amazingly the best sohc regrinds I have ever used were old man gude. The HCCS10 is a nasty cam.
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That's not bad for a car that obviously needs an alignment and suspension work. Solid 12 second NA D-series car with a little work.
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What sort of dyno numbers is he claiming? Because with how gutless the midrange on a D-series is going to be it probably needs a little top end to make the required power.
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I'm going to call those numbers Dynojet numbers and not pick it apart any further. I don't know the particulars of the setup (only really sifted the 1.4 liter build thread) but the power figure he mentions only calls for 130-135 wtq at 8000 rpms. With 13.5:1 I can marginally believe that number, since the dyno sheets are gone I can't see the way it goes down but if it's super peaky and making that power right at 9000 rpms that's 118-120 wtq. Getting the D16 to carry those numbers is the hard part, but a 1.4 is going to be more likely to do so.
There's a LOT that would have to be going on with the ports and valvejob, but I think it could be done. Not with *my* wallet, of course.
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well, i hit the dyno with the new cam. i tried to retard the cam 2 degrees to see if it made the torque carry even BETTER but it just slowed the spool and lost down low. no improvements up top. didnt have time to try 4 degrees. mb next time.
the cam makes less peak torque but it carrys it much much better resulting in higher overall output.
the bottle neck seems to be something other than the old bisi cam, but the new one helped.
new dyno
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old dyno
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If the power band falls off hard at either top or bottom end - or in your case, spool = midrange - then you have adjusted too far.
I wouldn't compare the Bisi cam to the stock cam's degree setting. Likely the Bisi's been ground on an arbitrary index.
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If the power band falls off hard at either top or bottom end - or in your case, spool = midrange - then you have adjusted too far.
I wouldn't compare the Bisi cam to the stock cam's degree setting. Likely the Bisi's been ground on an arbitrary index.
So JD are you saying the Bisi cam should be degreed in when installing to get the most out it?
Or are you saying that those cams are junk?
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any aftermarket cam should be degreed imho...
comparing the two graphs, the bisi cam made some good torque! if only i could have got it to CARRY that torque, i think it would have given me some decent power.
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If the power band falls off hard at either top or bottom end - or in your case, spool = midrange - then you have adjusted too far.
I wouldn't compare the Bisi cam to the stock cam's degree setting. Likely the Bisi's been ground on an arbitrary index.
So JD are you saying the Bisi cam should be degreed in when installing to get the most out it?
Degreed shmeed, you can do that with a timing light if you feel the need. Verify your piston to valve clearances so you know where NOT to adjust, and then spin the cam for the best powerband.
Or are you saying that those cams are junk?
No, but I am saying his turbo grinds are hit or miss. I'm a little annoyed with them over this Y7 car - Bisi has publicly stated that all his cams undergo R&D and make proven gains but he told my guy that he'd sold 2-3 of the grinds but didn't know what sort of power it made as he hadn't heard anything back. :mexi:
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Did you give Dave a kick when you were in at Miller?
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Degreed shmeed, you can do that with a timing light if you feel the need.
JD, the future of rapping. watch out Drake.
Did you give Dave a kick when you were in at Miller?
ya, but i let him get back to his slave labor welding gig. haha
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cough 74mm throttle body+spacer
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cough 74mm throttle body+spacer
cough sponsor me
;)
this new cam SMOKES the bisi cam all day
ran 11.51, previous best was 11.72
i am sure its got cageland in it with a little more seat time
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Ill cut you a smokin deal :yes:
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Ill cut you a smokin deal :yes:
PM'd
oh and i forgot to mention, i ended up taking out a degree of timing at peak torque and added 2-3 degrees up top.
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So what you are saying is Mustang dynos read lower than Dynapacks?
:P
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So what you are saying is Mustang dynos read lower than Dynapacks?
:P
i sure wonder.... 35ftlb less torque on my current dyno numbers, yet way better ET and picked up 4mph on average...
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Nice gains at the track. Pm sent regarding throttle body/spacer pricing up to canada.
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No, but I am saying his turbo grinds are hit or miss. I'm a little annoyed with them over this Y7 car - Bisi has publicly stated that all his cams undergo R&D and make proven gains but he told my guy that he'd sold 2-3 of the grinds but didn't know what sort of power it made as he hadn't heard anything back. :mexi:
He likes to talk up all of his products without any solid evidence that they even perform.
And yeah, fuck degreeing a cam. Just measure your clearances and play with the gear(s) to get the best combo. Degreeing will reduce the time it takes to get the cams dialed in, but it's also $200 less to spend for a degree kit(if you buy one, they're easy to make).
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Post your graphs here
http://honda-tech.com/showthread.php?t=2217467&page=10 (http://honda-tech.com/showthread.php?t=2217467&page=10)