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Hi all, I have a 2011 HSV Maloo (similar to the Pontiac G8 sport truck that didn't get released in America). It has the 6.2L (383ci) genIV LS3 engine in it. I have put a Harrop FDFI 1900 supercharger, 1 7/8 headers and twin 3 inch exhaust and a lumpy cam to suit the blower on it. I have no idea what the specs on the cam are, all I specified was that it had to be blower friendly. As is, it makes 560rwhp and it goes and sounds absolutely loving awesome. My problem is that I had never driven a cammed car before and didn't know what to expect. Yes I know, I've read heaps of magazines talking about "street manners' and 'driveability/streetability' etc in modified cars, but the reality is that its almost embarrassing to drive around town because of the surging/ bunnyhopping. My question is : will stroking it to 416ci improve the driveability without having to replace the cam? Will even just porting the heads help? Is it just a matter of doing something to improve torque low in the rev range (nothing happens below 2000rpm), or do I just have to put up with the cam and shut up? I would like to see 600 - 700hp or more out of this car eventually so I am keen to hear any ideas from those with more experience than me (everyone haha). Cheers! Also, why isn't there an LS3 thread already?  not my car, just a google images search, but same thing... Automatic Retard fucked around with this message at 09:09 on May 3, 2014 |
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May 3, 2014 09:04
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A couple things spring to mind. You have had the car dyno tuned with this setup, right? Seems like it would've blown up if not, but you didn't mention it. Knowing what can is actually in it would go a long way to figuring out how it's supposed to behave and how it might play more nicely. In general yes, a cam that is wildly aggressive on a smaller displacement engine is going to be a bit nicer on a larger one, but it won't be a night and day difference between the stock displacement and a 416 build. Also, take some pictures and some video of your ride, because god drat. 
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May 3, 2014 14:46
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Yea gonna need to hear that cam please. A blower cam in general shouldn't have much overlap and cause surging at low rpms. I agree that you should check the tune first on a dyno. I daily drive a cammed V8 and it drives fine, just a little weak on the bottom end but its smooth.
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May 3, 2014 16:40
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I agree. When you do a cam you need tuning, a bit different than for a blower. But now you have both so the #1 direction to go in should be dyno tuning. A hand held plug-in tuner ain't gonna cut it. With proper tuning you should see a good bump up in power over what you have now and get smooth bottom end, depending on what this cam is.
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May 3, 2014 17:55
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Get someone who absolutely knows what they are doing tunewise for this application, and it will be resolved. There have been tuners out there who can dial in everything but idle, and adjust idle by drilling holes in the throttle body. This isn't the right way to do it, and will cause the problems you describe, amongst others.
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May 4, 2014 04:23
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I thought I had a youtube account, but apparently I have a different one now, which I have to jump through hoops to find out my password. The poo poo I do when I'm drunk... The workshop that has done all the work so far is a reputable GMH approved workshop, and all tuning is done on a dynodynamics dyno. Is it possible to just go and ask them to retune it to sacrifice HP to regain low end torque/street manners with the same cam untill I get the cash/motivation to stroke it etc, or is it just a waste of time thinking that this thing will ever be nice to drive with this cam again... I have a quick vid from the last race event I went to that has the exhaust note, if I can figure out how to access youtube.....
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May 4, 2014 11:32
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It idles awesomely. It doesn't need revving to stay alive or anything, there's just no torque or power below 2000rpm. Sitting still like at the lights or in the garage it just rocks side to side. Awesome. Cruising around the suburbs though, it's not well mannered at all. What i'd like to know is if doing something to improve torque will fix this, or if its just a characteristic of cams in general that is something that people just put up with... Vids/pics will happen eventually
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May 4, 2014 11:40
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Yeah, you shouldn't be getting blower surge from a cam in a properly setup street application. Is it as bad as some of these? https://www.youtube.com/watch?v=GIALKZUnAc4 Seconding the "needs a proper tune" camp, and possibly a cam replacement. You don't know the cam profile that you have in it? That would help a lot. Also, stroking it out as a fix is horribly inefficient since you want streetability. Keeping what sounds to be a wild cam and adding cubes is just gonna exacerbate the problem. You'd gain the low end grunt you're looking for, but it's not really fixing the issue at hand, it's just spreading the animal over a wider RPM range. You might even end up with an even less tame engine. The profile of the lobes is your issue here, either a proper tune for timing, fuel etc. is going to fix it, or a swap to a more mild cam will. Beyond that I don't think there's many options. Seizure Meat fucked around with this message at 12:40 on May 4, 2014 |
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May 4, 2014 12:30
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Jesus gently caress, it's nowhere near as mental as those cams. Fuckit, I'm going to marshall what little brain power I have left right now to sort out this youtube retardation. Edit: yay i'm on the net. Sorry about the poo poo editing heres my car. https://www.youtube.com/watch?v=w75uteGIq_I Edit x2 : now that I've figured out youtube I could go and start it up in the garage, but it's 10'o'clock on a sunday night right now and the car is pretty loving loud. I'm quite drunk though..... Automatic Retard fucked around with this message at 14:52 on May 4, 2014 |
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May 4, 2014 14:15
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Excellent cinematography on that video :o
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May 4, 2014 15:15
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revmoo posted:Excellent cinematography on that video :o *obligatory "poo poo's upside down in Australia  " joke*
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May 4, 2014 15:18
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Is 500 hp streetable for you if you handle them like you handle a camera?
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May 4, 2014 15:52
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Ha ha fucken ha cunts.Yeah I tried to edit it but its beyond me at the moment But anyway, that's what it sounds like. I love it but it's a bitch to drive around town. How can I make it nice to drive again, without swapping the cam back out. I know I could talk to my tuner, and I will, but I want to know what the rest of the world thinks, and google gives me next to nothing on the subject. Automatic Retard fucked around with this message at 16:07 on May 4, 2014 |
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May 4, 2014 15:56
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How much time did it spend on the dyno? Around here, cars don't touch a dyno until they had a few street miles datalogged to get a good baseline. Then a little tweaking on the rollers to dial in all the part throttle maps. If your guys are setting idle and just doing WOT pulls, you're going to get those streetability issues. Something definitely seems wrong because you should be getting those numbers with a stock cam.
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May 4, 2014 16:24
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It isn't a stock cam. It had 470rwhp with the blower and cat-back exhaust. Now it has 560rwhp with the cam and headers. Everything else is stock apart from cam gears and valve springs, and probably some other things I can't remember right now. My google-fu is weak, it tells me gently caress-all about overcoming cam related power deficiencies. E: it doesn't spend much time on the dyno, it just gets the poo poo bolted on and then tuned to suit. Everything I get done at that workshop includes free tuning @~$900 E2: and yes, that's what's happening. They're setting idle and WOT I'm guessing. So you think some more loving around on the dyno will sort this poo poo out? Automatic Retard fucked around with this message at 17:08 on May 4, 2014 |
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May 4, 2014 16:53
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Oh my god I love those cars. I would slaughter a litter of kittens to get those in the States.
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May 4, 2014 17:29
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I was looking at buying a 2011 Camaro SS before I bought the HSV. Its was going to cost about AU$140,000 for something that costs US$40,000 in the States. That was when the Aussie dollar was stronger or as strong as the US dollar. gently caress that. They have the same engine, it's just been massively de-rated for Australia apparently. What's the import situation AU > US like right now?? Automatic Retard fucked around with this message at 17:52 on May 4, 2014 |
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May 4, 2014 17:46
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No clue, but if I ever hit the lottery I'm gonna get one of those fuckers. Or maybe I should just get a mining job in Australia.
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May 4, 2014 17:51
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You could, but you'll probably regret it. Unless you're already a functional alcoholic.
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May 4, 2014 17:55
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Importing them up to the US is a legal issue primarily. We can't import them as complete cars until they're 25 years old. But since we do have the G8 and GTO, there are companies that import the bodywork and convert them into utes so that they are still legally Pontiacs, not Holdens. And yeah, there's a big difference between someone who can just get it running safely, and a proper tuner that can actually make it run well everywhere in the range. The latter takes a very significant amount of time, even if they have a good baseline to start with (a tune for a car with the same engine and mods as yours).
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May 4, 2014 18:01
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I've heard that it's heaps cheaper to take the motor out and ship it all over as "spare parts" and then put it back together. But converting it from RHD to LHD or vice versa and then getting it rego'd is a big drama. .
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May 4, 2014 18:20
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But seriously, why isn't there an LS3 thread yet? Surely there must be a few modified Camaro/Corvettes in here? Am I the only one with a modified LS3 motor?
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May 4, 2014 18:28
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It would be cool if there was an LS? mod thread, I need something to drool over while I wait for my warranty to expire.
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May 4, 2014 18:36
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Automatic Retard posted:But seriously, why isn't there an LS3 thread yet? I'm acutally surprised there's not an LSx thread. It's such a common engine and there are a LOT of threads with builds focused on LS motors.
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May 4, 2014 18:43
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The obvious solution is to add a pair of turbochargers to go with the blower; it surges because it's lonely.
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May 4, 2014 19:08
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I'm seriously comsiderimg adding a centrifugal supercharger to it but I think they make the whole engine bay look ugly. I know that the positive displacement blowers are good at compressing air, but really poo poo at actually sucking it in... Maybe a small remote turbo? That'll give it more overall HP, but will it solve the everyday driveability issue?
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May 4, 2014 19:21
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Automatic Retard posted:I'm seriously comsiderimg adding a centrifugal supercharger to it but I think they make the whole engine bay look ugly. Either big single or V3si/Novi 2200sl. Streetablity will come from proper maf placement and a good tuner. A lot of horsepower doesn't always make a car better :P
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May 4, 2014 21:20
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I was under the impression that blowers were pretty good at providing low-end torque. Wouldn't a turbo either be so big that it would take some RPM to spool, or small enough that you'd effectively have half a sequential setup and thus be fairly complicated? Or is that not how it works?
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May 4, 2014 21:42
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Clearly, the answer is this.
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May 5, 2014 01:06
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Automatic Retard posted:I'm seriously comsiderimg adding a centrifugal supercharger to it but I think they make the whole engine bay look ugly. I had a D1-SC powered LS1 that made 681 RWHP (mild blower cam, headers, ported heads, LS6 intake, bigger crank pulley (for the blower), smaller blower pulley, and it was fully built. I'm near 100% positive a GOOD tune will fix your issue. Some of the first tunes I had resulted in similar issues, and I found the guy had tuned WOT, and "fixed" idle by drilling holes in the TB plate to allow it to idle. This wasn't the right way, obviously, and I didn't find out until I went to resolve them. A centrifugal blower won't fix the issue. My buddy with a LS1GTO had a maggie on it, and it had none of the problems you describe. The type of blower isn't your problem. In fact, a positive displacement blower should have even more down low than a turbo/centrifugal blower.
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May 5, 2014 01:53
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Automatic Retard posted:I'm seriously comsiderimg adding a centrifugal supercharger to it but I think they make the whole engine bay look ugly. More poo poo that will make the tuning even more complicated isn't going to help anything. And remote turbos are dumb and inefficient.
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May 5, 2014 01:56
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VikingSkull posted:Clearly, the answer is this. gently caress yeah Way2slow posted:I had a D1-SC powered LS1 that made 681 RWHP (mild blower cam, headers, ported heads, LS6 intake, bigger crank pulley (for the blower), smaller blower pulley, and it was fully built. I'm near 100% positive a GOOD tune will fix your issue. Some of the first tunes I had resulted in similar issues, and I found the guy had tuned WOT, and "fixed" idle by drilling holes in the TB plate to allow it to idle. This wasn't the right way, obviously, and I didn't find out until I went to resolve them. jamal posted:More poo poo that will make the tuning even more complicated isn't going to help anything. I didn't really think that adding more poo poo would make it nicer to drive, just that blowing air into the positive displacement charger would make heaps more power than just letting it suck its own air in, which these chargers are bad at. Exactly like that camaro above. I'm going to get an OTR and smaller pulley soon, so when they tune it to suit, I'll tell them I want the car to behave itself until I go racing, when I'll get it retuned for max HP. Anyway, the blower isn't the problem, it's only been a prick to drive since the cam and tune. It sounds like it can be tuned to be more docile for daily driving, while keeping the cam in it though, so I'll give that a go. Automatic Retard fucked around with this message at 02:31 on May 5, 2014 |
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May 5, 2014 02:26
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Automatic Retard posted:It sounds like it can be tuned to be more docile for daily driving, while keeping the cam in it though, so I'll give that a go. It can definitely be tuned to be better, but "how good" is going to depend on the cam. Even the LSx has its limits where a cam is not going to behave below 1500RPM if it's a stupid big cam.
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May 5, 2014 04:01
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West Australia represent! I was at Racewars last year (R32 GTR), those 800m roll-ons are a bunch of fun aren't they. Who was the tuner/workshop you used? The standard answer for V8 tuning in WA is WA Performance. Heaps of people swear by them. I would at least give them a call and have a chat to them about it. From what I hear there wouldn't be many people with a better reputation or more knowledge of these engines, in WA at least. http://www.waperf.com/
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May 5, 2014 05:48
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the obvious answer here is turbo-compounding
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May 5, 2014 06:01
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Dinosorcerer posted:West Australia represent! I was at Racewars last year (R32 GTR), those 800m roll-ons are a bunch of fun aren't they.  Yeah man racewars was awesome fun! It's a pity that there weren't any places left in the VMax top speed challenge by the time I entered. No great loss though, 'cos I was only getting up to 220kph over the 800m, so I wouldn't have been anywhere near competitive over 1000m. The overall winner got 306kph this year. I've had all the work done by Walkinshaw Performance FormulaTech so far... IOwnCalculus posted:It can definitely be tuned to be better, but "how good" is going to depend on the cam. Even the LSx has its limits where a cam is not going to behave below 1500RPM if it's a stupid big cam. Even 1500rpm would be better than 2000 Automatic Retard fucked around with this message at 07:35 on May 5, 2014 |
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May 5, 2014 07:32
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Knowing the specs of your cam would probably help. And to restate what everyone else has said, have the car tuned on the dyno. If you max power for racing then just add nitrous and or meth injection.
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May 5, 2014 07:47
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Automatic Retard posted:I'll tell them I want the car to behave itself until I go racing, when I'll get it retuned for max HP. You shouldn't need to have more than one fuel/ignition map unless you want one that restricts power to preserve the engine or keep things safer on the street; software changes in light, medium and transient load ranges won't affect those in the WOT range. They can probably fill in what they need to without even putting it on the dyno, just drive around with a guy on the laptop in the passenger seat. Ofcourse as others have said, this could be a moot point if it has an unreasonable cam.
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May 5, 2014 08:16
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I'm sure I'll sort it out, now that I know that there is, indeed, hope for it. Mods: can I start an LSx megathread type thing?
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May 5, 2014 13:36
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Automatic Retard posted:Mods: can I start an LSx megathread type thing? Sure, why the gently caress not
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May 6, 2014 17:42
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