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To Poncam Or Not To Poncam...that Is The Question?

allthewaytotheskyline
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allthewaytotheskyline Mentor

allthewaytotheskyline

Posted
Posted

ive got a r34 gtt rb25 neo

well im almost done buying up all my mods and then i stumbled upon PONCAMS...tomei 260's with 9.15mm lift.

now ive got a hks 2835 pro s kit internal gated with all supporting mods.

will this turbo im using require the investment of poncams for track days and or 1/4 mile time differences or will it just be a waste of money?

mind you its my weekender and will only see track days a few days in a year...must have driveability as i will mostly be streeting it and dont want it driving like a dog...plus will the 260 poncams give me more lag on the hks 2835 pro s?

so should i poncam or not poncam???

any advice or prior figures to help would be great..thanks in advance.

wolverine Grand Master

wolverine

Posted
Posted

on the S2 stagea they made more power everywhere so IMO they are a good thing but keep in mind that valve clearances will need to be checked and possibly require re-shimming. there were no losses down low just more grunt everywhere.

the time and cost might make it a lot more expensive than you expect so with a great turbo like you have on the way i would go ahead and install it without cams unless you can get the cams for a stupidly cheap price.

bass junky and abo bob have threads on this if you search.

allthewaytotheskyline Mentor

allthewaytotheskyline

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  • Author
Posted
on the S2 stagea they made more power everywhere so IMO they are a good thing but keep in mind that valve clearances will need to be checked and possibly require re-shimming. there were no losses down low just more grunt everywhere.

the time and cost might make it a lot more expensive than you expect so with a great turbo like you have on the way i would go ahead and install it without cams unless you can get the cams for a stupidly cheap price.

bass junky and abo bob have threads on this if you search.

yes ive searched but always open to people opinions and maybe someone had some new light to shed.

so more power everywhere but at the same time its not justifiable for $$$ to kw value is that what your saying?

i know that it will make more power up top but im definately not wanting to lose any power down low or cause more lag.

also what exactly are shims? sorry not full aware of how they affect cams and if need be how much will it cost to re-shim if you know?

joeyjoejoejuniorshabadoo Grand Master

joeyjoejoejuniorshabadoo

Posted
Posted

my car and bombtracks have the same mods, his with poncams, mine without

he gets 275 rwkw on PULP, i get 270

I get full boost a few hundred revs earlier

allthewaytotheskyline Mentor

allthewaytotheskyline

Posted
  • Author
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my car and bombtracks have the same mods, his with poncams, mine without

he gets 275 rwkw on PULP, i get 270

I get full boost a few hundred revs earlier

so am i following this right, bombtracks got poncams 275 rwkw with more lag

and you joeyjoe have 270 rwkw with less lag?

correct??

joeyjoejoejuniorshabadoo Grand Master

joeyjoejoejuniorshabadoo

Posted
Posted

correct....

in a real world environment stock cams ramp up more quickly. albeit only a few hundred rpm

on a dyno sheet the poncams dont look like they lose anything down low, because you sit in 4th @ a couple of thou and the cams are already starting to breathe before the pull has started, so they are on song right from the start of the curve.

in the real world you are changing gears all the time and launching etc and the controlled dyno curve never happens

poncams are a waste of money imho.

you have the same turbo setup as me, spend the money on a datalogit box instead and run e85, $600 delivered and i now have 311rwkw with full boost just before 3500

09ONE_32 Collaborator

09ONE_32

Posted
Posted

Cams are always worth it. It's basically like making your head artificially breath more. I think of it as a cheaper alternative then a port and polish to gain more head flow.

my car and bombtracks have the same mods, his with poncams, mine without

he gets 275 rwkw on PULP, i get 270

I get full boost a few hundred revs earlier

That sounds f**ked up. Were the cams dialled in properly with adjustable cam gears?

I have always gained power right through the rev range when upgrading cams. I made an extra 7rwkw peak but had another 21rwkw of midrage from 3500.

Fastrotor Proficient

Fastrotor

Posted
Posted (edited)

This is all relative too... depends on the turbo you are running too, a turbo thats maxxed out with lots of turbine inlet pressure can cause larger cams to drop power.

Edited by Fastrotor
joeyjoejoejuniorshabadoo Grand Master

joeyjoejoejuniorshabadoo

Posted
Posted

that's the turbo we are talking about...

same tuner, same dyno

both cars run a greddy rb26 ex cam gear and the cams were dialed in properly

tuner is rob @ created

i was speaking to ben from racepace a little while ago and he was telling me nit to go for cams, citing the reason i stated earlier.

he was saying that with many of his customers track cars he returns them to stock cams and sees an improvement in lap times,

bombtrack Experienced

bombtrack

Posted
Posted

This is JJJ's dyno sheet from the first tune:

http://i295.photobucket.com/albums/mm144/h...n/dynosheet.jpg

This is mine:

http://img293.imageshack.us/img293/4052/ji...ismdyno2qj4.jpg

This is a fairer comparison between our tunes as Rob hasn't had a chance to fix my inj. latency's or shim the cams properly. JJJ is now running 270rwkw after a second tune. I am expecting a slight increase in power after my second creatd tune for the reasons mentioned before.

I am yet to be convinced about poncams one way or the other but what I can say is that at our power level, there may be a difference in amount and delivery but it's f**k all.

Cheers.

wolverine Grand Master

wolverine

Posted
Posted

having looked at both graphs it looks like it takes more boost to make similar power.

this doesn't prove one way or the other that cams are good value cost/benefit but it seems cams make it breath better.

i don't have back to back dyno prints +/- the cams but on the stagea, i was concerned it would lose down low but the car was better everywhere on the road. with a big heavy lump like a stagea carrying an extra 350-400kg it was a genuine concern if we lost down low and we didn't.

since there are so many variables with cars, engine condition, temperature, fuel, tuning etc it is hard to get quality back to back testing on a single car let alone comparing two different cars.

bombtrack Experienced

bombtrack

Posted
Posted

I don't disagree with you at all. I don't have good enough evidence to suggest one way or the other. All I know is that cams did NOT hurt performance and in fact gave a little extra (ON PAPER), so why not!? :)

Tangles Grand Master

Tangles

Posted
Posted

yeah i can vouch for the Stagea working well with poncams (non-neo)

simply feels like a 3litre.

upgrading my turbo right atm, my slide highflow is off and putting a GT3071r on

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