auto-accessories-inc.

Whats the pros/cons of using n/a cams on an turbo set-up?
ok say im currently boosting 10psi and dropping 277 whp on a stock head B18B


Modified by auto-accessories-inc. at 7:53 PM 7/23/2007


Modified by auto-accessories-inc. at 8:54 AM 7/25/2007

quicksilver1689

the duration might not be optimal for high power turbo applications, maybe some reversion?

auto-accessories-inc.

bigbadboy

it all depends on your exhaust manifold and set up

auto-accessories-inc.

well its a turbonetics t03/t04e, log mani 750 cc injectors

bigbadboy

w/ a log mani u'll be better off with turbo cams. all motor cams work better with equal length manifolds and such

tony413

ok exactly what companies turbo cam are you wanting to know about vs. their N/A cam

auto-accessories-inc.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony413 &raquo;</TD></TR><TR><TD CLASS="quote">ok exactly what companies turbo cam are you wanting to know about vs. their N/A cam </TD></TR></TABLE> Well like JG engine dynamic N/A cams vs. say comp or crower turbo cams not one specific company.

tony413

well all motor cams usually have has less lift than turbo cams because the n/a cams have longer durations.
the longer duration overlap are so that the motor can suck in more air at higher RPMs to help with its V.E.
turbo cams have a higher lift and usually very short to no duration overlap. this is because when the turbe is "pushing" air into the motor the cams need to make sure theres no overlap or else the "forced air" well just flow into the exhaust. the higher lift often assoicated with turbo cams is there to help more air get stuffed into the motor because there is no overlap.
i hope that give you an idea of what our looking at

JDogg

in every test i have done turbo cams sucked ***.

the last test we did was on a 1.9liter b16 with a one *** manifold and a gt40r, gong from crower turbo cams to CTR cams, we picked up about 40hp on low boost

HiProfile

But that was low boost with a big turbo and most likely a very nice ex mani. Every PSI on the intake gets you 2-3 psi in the exhaust mani on average, obviously less with a better mani, bigger turbine, etc. But at some point reversion becomes an issue. I've been trying to wrap my head around this oddity in cams for a long time, I just find it so odd that NA cams work so well on most well-built Hondas. W/o a huge education in fluid dynamics or engine (exhaust) theory, I'm stuck with common sense

One thing to think about is dyno graphs of turbo Hondas vs Factory Turbo cars (even modded ones) - Hondas hold torque well, while Factory Turbo engines, even blocks of nearly similar displacement, fall flat on their face. One good example I recall was an MX6 that hit peak torque (400 or somehting) by 3200, and only made 430whp due to a brick-in-water drop in torque.

auto-accessories-inc.

ok heres what im working with:
B18b built bottom end 9.5:1 comp.
skunk 2 intake mani
RC750cc
turbonetics t3/t4oe w/log manifold
tial 38mm wg
motor already did 277 in my integra looking 325-350 with a built head.
need to find the best stick for the buck=whp.
crower turbos,n/a- JG- comp-crane what are guys using to get the best power overall.

alterdcreations

i would go for the n/a cams
you would gain some off boost power and you might be able to run more boost and make more power safer due to the overlap.

don't those hks evo cams have like 276 valve duration(+ or -) with 12+mm of lift?

thats what cam gears and p/v clearance/ & v/v clearance is for

auto-accessories-inc.

sounds good but what are others using on here??

integraXTC

anyone use turbo cams on an ls-t and switch to n/a cams? experience?

JDogg

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile &raquo;</TD></TR><TR><TD CLASS="quote">One thing to think about is dyno graphs of turbo Hondas vs Factory Turbo cars (even modded ones) - Hondas hold torque well, while Factory Turbo engines, even blocks of nearly similar displacement, fall flat on their face. One good example I recall was an MX6 that hit peak torque (400 or somehting) by 3200, and only made 430whp due to a brick-in-water drop in torque.</TD></TR></TABLE>

its because their heads suck... Look at most supra dyno graphs, they are just as you describe... brad z worked some major magic on my buddys 2jz head and the dyno graph and the tune looks like its a honda .. good.

as for the big turbo/nice mani theory... idk. we have a 2 liter gsr with blox B cams and a drag turbo kit. those cams work VERY well in that engine, it made 380 on 10lbs of boost, peaking around 9000 rpms and holding power very well at 9800 rpms where we stoped reving it.

EG civic

Dont forget to look at skunk 2 cams, they are great camshafts!

auto-accessories-inc.

but great in an LS head? i want to get the best i can for the $ and performence. are there any N/A cams putting decent numbers say comparable to the crower 403's?

JDogg

idk about an LS head, but i do k now that JG turbo cams dont work that great.

throw it away and put a vtec head on it, you can leave it stock and make more power than any cams would in the ls head

auto-accessories-inc.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">idk about an LS head, but i do k now that JG turbo cams dont work that great.

throw it away and put a vtec head on it, you can leave it stock and make more power than any cams would in the ls head</TD></TR></TABLE> yeah but im already dyno'n near 278whp im just trying to get 300-325 without sleeving the block

tony413

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">idk about an LS head, but i do k now that JG turbo cams dont work that great.

throw it away and put a vtec head on it, you can leave it stock and make more power than any cams would in the ls head</TD></TR></TABLE>

not to be a dick but if the guy didnt ask about using vtec stay on topic of the LS head and cams. also buying a pair of $200-$450 cams is still alot cheaper than a Vtec conversion. besides think about all the other companies with similiar head designs as the LS, they dont use vtec but still flow pretty good

JDogg

he's asking about cams... most of even the biggest ls cams are still smaller than ITR cams

tony413

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">he's asking about cams... most of even the biggest ls cams are still smaller than ITR cams</TD></TR></TABLE>

no they are not here let me get the specs for you

CROWER LS CAMS 62404-2
62405A-2

Duration Duration @ .050 Gross Lift w/ 1.75
276 / 272 226 / 224 445 / 434
322 / 319 241 / 238 478 / 469


STOCK CTR CAMS

Duration Duration @ .050 Gross Lift w/ 1.55
294 / 305 240 / 232 447 / 416 Identical to 00-01 ITR cams
294 / 286 233 / 224 449 / 417 Identical except that CTR has 3* more duration on intake than ITR

looking at the comparisons you see that the Vtec only allow for about 2-4* more of over lap, but they also use less gross lifts and at that point theres less overlap than the biggest LS cams. one thing to think about is that you(JDogg) didnt mention the aftermarket cams that are availible for vtec engines an if you go that route then yes i totally agree vtec is the way to go


Modified by tony413 at 12:14 PM 7/26/2007


Modified by tony413 at 12:15 PM 7/26/2007

ATYPR

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">

as for the big turbo/nice mani theory... idk. we have a 2 liter gsr with blox B cams and a drag turbo kit. those cams work VERY well in that engine, it made 380 on 10lbs of boost, peaking around 9000 rpms and holding power very well at 9800 rpms where we stoped reving it.</TD></TR></TABLE>



I have a 81mm b16 with a t3/t4e, drag manifold, and ITR cams. I was told that the cams would be too big but my car made 398whp on 18psi.

auto-accessories-inc.

yeah and im looking to make 325 safely on a b18b. ive seen some b18b go near 4-500 whp im just looking for a fun track 1/4 mile *****. not a daily driver.