Do I need cams?

[roast]

I'm finally getting my Silvia back in gear and in the last year I picked up a GT2871R to replace my T3 Super .60... I'm not being very smart about the upgrade process and think i'll have a lot of low end lag and need something to make up for the larger turbo. I was wondering if I need poncams to help make up for loss of spool by using the larger turbo?

I'm going standalone SDS w/800cc injectors.

[D_Stirls]

How much lag are you seeing, I'm running the same turbo (52trim 0.64a/r) and i'm seeing 17psi at around 3700rpm. Cam's generally won't help you to reduce lag but they will make the engine more efficient when it is on boost. Adjustable cam gears will allow you to move the power around slightly but any gains you have in the bottom end will cost you in the top end.

EDIT!!
Tuning in the boost transition will have a big effect on the boost threshold, so if your tuning is out particularly in that area nothing will help.

Taken from NIStune Manuals;

You should be seeing around stoichiometric in
the light load areas, then getting richer as soon
as boost starts to rise. Check the “boost
transition” areas too. Usually around the centre
of the map at 2500 – 3500 rpm. A lean spot here
makes for very lazy boost response.

[boost_boy]

I'm finally getting my Silvia back in gear and in the last year I picked up a GT2871R to replace my T3 Super .60... I'm not being very smart about the upgrade process and think i'll have a lot of low end lag and need something to make up for the larger turbo. I was wondering if I need poncams to help make up for loss of spool by using the larger turbo?

I'm going standalone SDS w/800cc injectors.

If you don't have the money to dump on them, then I wouldn't go out of my way to get some, either. I don't know what you really want out of your engine when it comes to performance, but make sure you contact me when you're ready as I have a remedy to fix your supposed lag issue. I run a GT35R dual ball bearing with a .63 exhaust housing and I love the way it comes onto boost with full boost being available at or around 4500rpm, so again it's all about where you want all the action to take place at. Remember, the CA is a dog before 4000rpm IMHO, but with the SDS and proper tuning, you can make the car very driveable off boost and set it up so that it transitions nicely to and through your boost curve. I'll have that gear you need in the mail Monday due to the fact that I've been coaching little league football, so my time has been shot throughout the week. We'll be in touch on this tuning thing .

[r34 gtr]

Yes. High-lift camshafts are awesome.

[roast]

If you don't have the money to dump on them, then I wouldn't go out of my way to get some, either. I don't know what you really want out of your engine when it comes to performance, but make sure you contact me when you're ready as I have a remedy to fix your supposed lag issue. I run a GT35R dual ball bearing with a .63 exhaust housing and I love the way it comes onto boost with full boost being available at or around 4500rpm, so again it's all about where you want all the action to take place at. Remember, the CA is a dog before 4000rpm IMHO, but with the SDS and proper tuning, you can make the car very driveable off boost and set it up so that it transitions nicely to and through your boost curve. I'll have that gear you need in the mail Monday due to the fact that I've been coaching little league football, so my time has been shot throughout the week. We'll be in touch on this tuning thing .

Thanks for the info, I'll use your tuning advice and get used to the car on SDS. I do have a budget, it's relatively low, few hundred to a thousand here and there is fine... I want to build a weekend car for fun, something that'll reliably handle some lapping days at the local tracks and or a few drag test and tune visits per summer.

[roast]

Yes. High-lift camshafts are awesome.

I had a high-lift camshaft in my old 5.0L (back in 1997), man was that fun!

Why would one need to go poncams or procams? What type of builds target these upgrades on our CA?

Max HP
Drag
Drift
Auto-X
Lapping
Modified Daily Driven

[roast]

How much lag are you seeing, I'm running the same turbo (52trim 0.64a/r) and i'm seeing 17psi at around 3700rpm. Cam's generally won't help you to reduce lag but they will make the engine more efficient when it is on boost. Adjustable cam gears will allow you to move the power around slightly but any gains you have in the bottom end will cost you in the top end.

EDIT!!
Tuning in the boost transition will have a big effect on the boost threshold, so if your tuning is out particularly in that area nothing will help.

Taken from NIStune Manuals;

You should be seeing around stoichiometric in
the light load areas, then getting richer as soon
as boost starts to rise. Check the “boost
transition” areas too. Usually around the centre
of the map at 2500 – 3500 rpm. A lean spot here
makes for very lazy boost response.

The turbo isn't installed, I'm getting the CA back together after i starved the motor of oil last fall. Thanks for the info on adjustable cam gears, I never thought about them however if I find that I have a top end that's never used and I want more torque down low, i'll consider it.

I'm hoping Dee's advice with SDS will help me tune boost transition, I've studied the maps and systems and think it's very straight forward.

Part of what matters is when you're driving beside your buddy with a s13/s14, you can step on the throttle and beat his a**... Yes, I don't want to be left waiting for boost to spool like I did with the T3 Super .60. (I still loved the rush the T3 gave at 18psi!)

What I certainly lack is experience and exposure, I'm glad to be a member here at Nico and specifically the CA18DET forum!

[float_6969]

I'm sure Dee knows all of the tricks, but there are some tuning things that can be done to help spool the turbo, and make it run smoothly in the transition period.