ringram
Author
Discussion

kaw

Original Poster:

1,081 posts

215 months

Monday 26th October 2009
quotequote all
hi mate need help cam or 1.8 rockers or both .car r8 ls2 auto.looking at otr as well and then what about mapping to get it running right ,moneys tight so with the help of a good friend may get it done right cheers rick

ringram

14,702 posts

279 months

Monday 26th October 2009
quotequote all
Depends what you have now.
I managed 360rwhp with otrcai and rockers on my ls2, no other mods, stock exhaust still etc.
So thats only 7rwhp less than the Fish full £5000+ cam kit. All in cost probably £600, so a good saving for a loss of 7rwhp. Of course that doesnt include fitting and tuning.. But is a good example of what the DIY approach can achieve.
Go for the 1.85:1 rockers if you are going to do them. I think SLP do some stock type ones at that ratio.

Of course a cam and supporting mods will cost more, though should break 400rwhp easy.

Usual story, whats your target?

kaw

Original Poster:

1,081 posts

215 months

Monday 26th October 2009
quotequote all
custom exhaust crap induction kit, to be changed to an otr and auto remap and engine remap to suit.looking for 400 rwhp and thats as said on a auto as they lose a bit more . garth has a monkfish cam coming up so do i go for cam and rockers

kaw

Original Poster:

1,081 posts

215 months

Monday 26th October 2009
quotequote all
kaw said:
custom exhaust crap induction kit, to be changed to an otr and auto remap and engine remap to suit.looking for 400 rwhp and thats as said on a auto as they lose a bit more . garth has a monkfish cam coming up so do i go for cam and rockers

MyM8V8

9,468 posts

226 months

Monday 26th October 2009
quotequote all
ringram said:
Depends what you have now.
I managed 360rwhp with otrcai and rockers on my ls2, no other mods, stock exhaust still etc.
So thats only 7rwhp less than the Fish full £5000+ cam kit. All in cost probably £600, so a good saving for a loss of 7rwhp. Of course that doesnt include fitting and tuning.. But is a good example of what the DIY approach can achieve.
Go for the 1.85:1 rockers if you are going to do them. I think SLP do some stock type ones at that ratio.

Of course a cam and supporting mods will cost more, though should break 400rwhp easy.

Usual story, whats your target?
And a heck of a lot of logging and (expert) tuning though to get it all!You were mafless,right?

What he was asking Rich is, what do you think his gains would be with a MFish magic cam (if he got one cheap) AND the RR's.

I think his target is 400rwhp.

Rick. Tinker27 has a set of CNC (LS2) 243 heads You might want to ask what he wants for them.

Just shows you how good the stock VE R8 exhaust is (Note, Vizzard style resonator box etc.)

ringram

14,702 posts

279 months

Monday 26th October 2009
quotequote all
Well thats a different kettle of fish then!
I had 386rwhp with my LS1 and all the bolt on's. With better heads and a cam 400rwhp would be ok, just.

Cam only LS2's can drop 400rwhp with supporting mods. Maybe more. So for you with your auto you will need to really work on it. You "might" just squeek in with a fast92 intake, underdrive and decent cam & springs, pretty much what Gareth has now. Actually ask him what his is putting down. I dont think he hit 400rwhp with it. But he has added the Fast intake since then. You will also need a good exhaust etc.

Failing that a good set of heads will take you over your goal. But they can be pricey. If I was in the market for LS2 heads, I might even be temped to do what GelfVXR has done and fit some L92 heads. I suspect he will be at the dyno day with his setup which is well thought out.

For best power something like the TFS or CNC Ported Darts would be good. You would be up for around $3000 USD plus the usual stuff just for heads.

Have a poke around on LS1.com.au to see what they guys there with auto's are making and what mods they use to give you an idea on what you are up for. Basically a full NA package!

MyM8V8

9,468 posts

226 months

Monday 26th October 2009
quotequote all
The point about the small cam with the rockers is something I touched on in another thread.

You were talking about a school of thought on small cams with high lift being the go with these motors.

ringram

14,702 posts

279 months

Monday 26th October 2009
quotequote all
Yeah high lift goes without saying. In which case stock rockers are fine otherwise you will have too much lift. Its kind of either or really.
Then stuff like duration and lobe separation to set the RPM range and power band.
I like good torque and power to redline, but not past then. So that means mid duration stuff. Pointless doing anything less than 22x duration at 0.050 IMO. Even in an LS1.
Some aftermarket heads will require roller rockers though. I know TFS do. Though engine builders say thats because they have messed the valve angles up.
You could do mental and set yourself up with a screamer. Emissions will fail, you will need to upgrade rod bolts and heads to support the RPM. Then cam it large! But it will run fast. Not my kettle of fish in a daily driver though.

kaw

Original Poster:

1,081 posts

215 months

Monday 26th October 2009
quotequote all
this is now way over my head

ringram

14,702 posts

279 months

Monday 26th October 2009
quotequote all
.. basically heads and cam required IMO smile plus the usual extra's

Bonnie and Clyde

11,701 posts

223 months

Monday 26th October 2009
quotequote all
ringram said:
Yeah high lift goes without saying. In which case stock rockers are fine otherwise you will have too much lift. Its kind of either or really.
Then stuff like duration and lobe separation to set the RPM range and power band.
I like good torque and power to redline, but not past then. So that means mid duration stuff. Pointless doing anything less than 22x duration at 0.050 IMO. Even in an LS1.
Some aftermarket heads will require roller rockers though. I know TFS do. Though engine builders say thats because they have messed the valve angles up.
You could do mental and set yourself up with a screamer. Emissions will fail, you will need to upgrade rod bolts and heads to support the RPM. Then cam it large! But it will run fast. Not my kettle of fish in a daily driver though.
WTF yikes

Moanro5.7

7,337 posts

210 months

Monday 26th October 2009
quotequote all
ringram said:
Yeah high lift goes without saying. In which case stock rockers are fine otherwise you will have too much lift. Its kind of either or really.
Then stuff like duration and lobe separation to set the RPM range and power band.
I like good torque and power to redline, but not past then. So that means mid duration stuff. Pointless doing anything less than 22x duration at 0.050 IMO. Even in an LS1.
Some aftermarket heads will require roller rockers though. I know TFS do. Though engine builders say thats because they have messed the valve angles up.
You could do mental and set yourself up with a screamer. Emissions will fail, you will need to upgrade rod bolts and heads to support the RPM. Then cam it large! But it will run fast. Not my kettle of fish in a daily driver though.


Like the sound of a screamer, but as u say not a good everyday car. gotta give it loads of revs to get it going, But be nice biglaugh

Brummmie

5,284 posts

252 months

Tuesday 27th October 2009
quotequote all
I had valve float thanks to 1:85 roller rocker from Comp Cams, it set in at around 5.8K, and killed the motor at about 6.2K. I have Dart heads with slightly bigger valves and Gold valve springs. I changed to standard rockers and she revved straight through to 7k and PICKED up torque below 3K. Lost around 7RWBHP at peak, but the extended rev range blew that trade off. Not to mention not stressing the valve gear and hopefully avoid catastrophic failure.

ringram

14,702 posts

279 months

Tuesday 27th October 2009
quotequote all
Which is precisely why I mentioned the SLP rockers smile



"These replacement high-ratio 1.85:1 rockers from SLP are made by the same company that supplies GM, which explains why there are no markings whatsoever to differentiate them from the stock 1.7:1 rockers other than a dab of red paint on each tip. Be cautious when using higher-ratio rockers on heads with stock beehive valvesprings and bigger cams, as coil-bind approaches with valve lifts over about 0.585 inch."

Brummmie

5,284 posts

252 months

Tuesday 27th October 2009
quotequote all
Yep, they should be better, but you will still have more rocker tip speed because of the longer arm, if you are going to cam it, then do it that end. But if you are just going to do rockers then these look like the best option.

ringram

14,702 posts

279 months

Tuesday 27th October 2009
quotequote all
Agreed.

justsoldit

129 posts

230 months

Tuesday 27th October 2009
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Ringram.. please don't shoot me for suggesting this, but surely peace of mind has to play a part when modding a newer car for example? I have a horrible feeling that "DIY" car mods may be outlawed in the not too distant future, and only performance modifications carried out by "certified" establishments will be legal. I doubt they would ever apply this kind of legislation retrospectively, but personally I'd rather pay Mr Fish his £5k to cam a new VXR8 for example, knowing it's likely to remain road legal. Plus, you have the option of having expert assistance to sort any issues. I'm not questioning your knowledge and expertise, nor anyone on this forum, but I personally wouldn't be confident swapping parts of the engine, or even purchasing them independently and asking a less recognised workshop to fit them. I know we're only talking engines here but if people started tinkering with suspension for example, it could be a dangerous saving. Just an opinion, be gentle.

Edited by justsoldit on Tuesday 27th October 17:47

MyM8V8

9,468 posts

226 months

Tuesday 27th October 2009
quotequote all
justsoldit said:
Ringram.. please don't shoot me for suggesting this, but surely peace of mind has to play a part when modding a newer car for example? I have a horrible feeling that "DIY" car mods may be outlawed in the not too distant future, and only performance modifications carried out by "certified" establishments will be legal. I doubt they would ever apply this kind of legislation retrospectively, but personally I'd rather pay Mr Fish his £5k to cam a new VXR8 for example, knowing it's likely to remain road legal. Plus, you have the option of having expert assistance to sort any issues. I'm not questioning your knowledge and expertise, nor anyone on this forum, but I personally wouldn't be confident swapping parts of the engine, or even purchasing them independently and asking a less recognised workshop to fit them. I know we're only talking engines here but if people started tinkering with suspension for example, it could be a dangerous saving. Just an opinion, be gentle.

Edited by justsoldit on Tuesday 27th October 17:47
Mate you are on a pistonhead forum! I doubt anyone would take unecessary chances, especially with the kind of motors we are talking about here.

Having seen and heard of some of the work done by certain "professional outfits" I would rather do the work myself, and some of them do need certifying!.

I hope you are wrong about that proposed law. It's going to cost folks dearly. It's another ridiculous symptom of this nanny state. Free world-You must be joking! Don't they trust their MOT stations to properly inspect cars?

What a fking st hole country this is turning out to be! Or is it those tossers in Brussels trying to protect the supercar manufacturers from being humbled by us?

Lastly, people who tinker with what they don't understand have got to be downright bonkers!

Edited by MyM8V8 on Tuesday 27th October 18:26

justsoldit

129 posts

230 months

Tuesday 27th October 2009
quotequote all
[quote=MyM8V8]

Lastly, people who tinker with what they don't understand have got to be downright bonkers!

quote]

Exactly what I was trying to say.. we can't assume that everyone understands what they're doing so the more knowledgeable amoungst us should be wary of this when giving advice.

I also agree about the legislation, I hope it doesn't happen either. It was first brought to my attention on a land rover forum - as my second vehicle is a defender, which is like a meccano set! Just a bit slower than the R8.tank

I'll respect you're opinion about some professional outfits, but I'm confident the Fish know what they're doing... good point about where we are... I'll zip it.

ringram

14,702 posts

279 months

Tuesday 27th October 2009
quotequote all
Suffice to say, Im with Gareth on this on all counts.