Cams Now Or Next Round?

[joeyjoejoejuniorshabadoo]

Hey guys, just after a few opinions. My 33 t is goin in to racepace soon for a gt 2835 pro s and i was going to do poncams at the same time... But of course its just more cash.

i spose my question is this...

Do i really need the poncams right away or will i be happy enough with the power delivery of the pro s on stock cams. I'm going the pro s as ben has assured me that he can give of a safer tune on it than with a gtrs. And also as a easier to live with daily option

The cams will go in eventually anyway. I was just now thinkin of doing them as a round 2 with tb and possibly plenum if i can find one that keeps my injectors and fuel rail. (Possibly plasmaman but i havent really looked hard yet)

doing this will allow me to do a little suspension work in place of the cams. Back end will need to be a little tighter i spose with the pro s

the car is a daily driver and has all the supporting mods, also i'm not after a heap of other turbo choices.

soooo... To poncam or not to poncam... That is the question.

[NYTSKY]

The 2835 has a fast spool compared to something like a 3037 which would benefit alot with cams.

Cams with a 2835 would be really nice to drive and would produce some high numbers on the dyno.

But i dont think it would be needed for you to enjoy the turbo.

If i were you i would by some nice coilovers(thats what i would do anyway)

[75coupe]

IMO, go the suspension before cams... you have a heap more power with the turbo but as always with more power you'll need to be able to deliver it well... as in suspension mods... and you can later refine the power delivery with the cams...

[R31Nismoid]

Have a chat to benno about it, he is the best person to ask these things, and doesnt make you spend money where you dont need

[joeyjoejoejuniorshabadoo]

Fair call ash... I'll post the answer when i call

[RB30-POWER]

i wouldn't go out of your way to do cams, that turbo still sounds small in the scheme of things.

until your doing towards a consistant 300rwkw at the treads, i wouldn't waste money personally, the gains per $ just not worth it.

if your got money to blow but, go ahead...

[joeyjoejoejuniorshabadoo]

Well i'm not after cams to gain 10kw at 7000 revs in fourth gear... I'm more thinkin bout offsetting some lag (i know its not a lag monster anyway)

[RB30-POWER]

even so, response with that turbo will not be an issue.

[joeyjoejoejuniorshabadoo]

Yeah, thats what i was thinkin... Hence this thread

[RB30-POWER]

let us know what you find either way

[paulr33]

i think you will find its not worth it

it might be 5kw midrange difference - spend it on suspension or something given 1k is a reasonable price for cams fitted

[RB30-POWER]

i remember a guy on here fitted poncams and lost power, anyone know if he ever worked out what happened?

that was a strange case indeed...

considering most people pick up midrange with them, as you should too!

[joeyjoejoejuniorshabadoo]

Yeah, i'll see what ben says and then blindly follow that

either way i'll post a full rundown on here when its all done

[R31Nismoid]

From what i can gather, the transient response is better with the smaller cams.

Hence most of the track GTR are running factory (or modded factory) cams.

Its stuff that you'll never see on a dyno.

All the GTR's ive been for runs in feel sensational, heaps of power everywhere, much like my own RB26 setup now

[joeyjoejoejuniorshabadoo]

Yeah, i'm leaning towards not going for cams yet i think... I can always do them at a later date if i'm not happy

besides... a 2835proS is expensive enough as it is!

[BHDave]

my mate saw next to no gain when he added hks cams with a 2835proS. went from a previous peak of about 269 to about 271rwkw, same dyno, same tuner.

[Leadfoot]

Yeah, i'm leaning towards not going for cams yet i think... I can always do them at a later date if i'm not happy

besides... a 2835proS is expensive enough as it is!

Just for your reference:

I did the HKS 2835 Pro S with poncams about 4 months ago.

For reference here is the engine rpm versus gear at 1.0 bar boost (RB25DET R33 no other mods):

1st gear: 3900 rpm (additional dynamic lag is most noticable in this gear but also least important. Pulls a bit harder than stock with a big rush at the end)

2nd gear: 3500 rpm (pulls well from 3000 but really hits at 3500, can lose rear end traction with poor tyres. Better than stock everywhere.)

3rd gear: 3200 rpm (does not feel laggy at all at any speed. Very useable above 60 km/hr (EDIT - just verified) )

4th gear: 3000 rpm (becomes a much more useable gear once the 2835 is in. Stock turbo did not have quite enough guts in 4th.)

5th gear: 2800 rpm

The smoothest transient offboost to boost power delivery was obtained by setting up a 4 stage manual boost control to bring boost on as early as possible.

That way power did not arrive late and in one big hit and 2nd gear rear wheel spin was sorted.

I tend to agree that it might be money wasted, however money was not the object and I did not want to compromise but thats just me.

The car is used on motorkana tracks with low speed 2nd gear corners and even with the poncams there is still a small amount of lag on corner exit of about one to two seconds.

The other benefit of poncams is a lower dynamic compression ratio (more overlap) which may help improve engine longevity.

To achieve your power goal the tuner will be able to run a more conservative tune or alternatively run lower boost levels, all of which may also help the motor last longer. The value of this, not sure, but thats how I justified it to myself !!

Edited December 26, 2007 by Leadfoot

[joeyjoejoejuniorshabadoo]

A1 post! Thanks!

[tridentt150v]

i remember a guy on here fitted poncams and lost power, anyone know if he ever worked out what happened?

that was a strange case indeed...

considering most people pick up midrange with them, as you should too!

That happened to me.........240 before and 225 after cams BUT the tuner f#*ked up, he added about 4-5 degrees on my tomei exhaust cam pulley, with Tomei 256/8.5 cams [i now know and realise thanks to this forum] you don't need any offset, it should have been reset to zero. I did this myself back at home after getting the story from SAU and the power difference was very noticable, it was extremely lively - but the PFC wasn't properly tuned for it. I was going to get it retuned [expected say 250rwkw], but I went stupid and brought a HKS cast low mount, 40mm HKS wg, and a Garrett 3076 WG with all the gravy and the rest is history.

[tridentt150v]

BTW, I brought my cams to offset lag and help the breathing etc, i figured that the easier it breathes, the lower the lag.

I've extrude honed my manifold, match ported my turbo and gasket, and [one day when I take it off the road again] want to flow the head and inlet manifold [although inlet manifolds flow OK std but like everything else can benefit from a clean up]. I only use my Skyline for road, I don't [can't afford, well I can afford, but there are competing priorities like 4wd's, m/c's, and housebuilding] race it, so probably won't change the inlet to a Greddy or somesuch.

And I always intended to go to a bigger turbo than std hiflow, so the cams were part of a future plan I had.