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GEN IV L92 VVT Cam Help...

 
Old 03-12-2019, 02:09 PM
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Default GEN IV L92 VVT Cam Help...

Hey guys, I've read tons of articles and I think I've landed on the cam I want, but I want to run it by the experts to see if I'm overlooking something.
I have 65 impala SS with the 6.2 L92 out of a 07' denali, and I'd like to get some more punch out of it. It's a VVT engine and doesn't have AFM/DOD. It's got:

-Truck L92 Intake
-LT Headers
-CAI
-Stock L92 TB, injectors, rails
-3.73 gears
4L80E Trans- Stock torque converter
This isn't a race car nor is it daily driven, but I want good street performance and I like to be able to take it down the track and around some curves with some purpose. It still needs to behave on the street. Almost all of my driving is street driving, highway trips, back roads, and I'm hoping for the occasional track day. I am much more concerned with a broad powerband and area under the curve than an all out, peak number.
I've been eyeing this new version 2.2 L99 VVT cam from TSP https://www.texas-speed.com/p-5770-n...-camshaft.aspx
Cam Specs: 227/239, .629"/.629", 113 LSA
I'm planning on getting the kit, which includes springs, pushrods, ect.

I'm also prepared to upgrade the torque converter to match the cam (I'm looking at a Yank SS3200).
Does anyone have experience with this cam in an otherwise stock L92 and care to chime in on it?
Any other supporting mod I need to be aware of when swapping to this cam?
For what I'm after, does this cam choice seem appropriate?

Thanks
Nick

Last edited by nicke; 03-12-2019 at 02:21 PM.
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Old 03-12-2019, 03:24 PM
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What controller do you plan to run, and is there proven data that an aftermarket tuning program such as EFI-L or HP-T can control them somewhat accurately? I think the aftermarket cams limit the VVT amount via spacer blocks in the VVT actuator, so their effect should also be somewhat limited but there should be gains nonetheless. Spring pressure can greatly affect proper VVT control as well, so get in bed with TSP if or when you buy and install it and follow their recommendation.

Sorry, I didn't answer your question, but I will be watching this post as well for the answers. I have the same engine going into a Colorado, also wanted VVT, but did not spend enough time researching proven control of the VVT system via an aftermarket tuning program, into an ECU operating system which did not have it for that specific year (stock 2009 E67 in Colorado 5.3L).
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Old 03-12-2019, 04:32 PM
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Originally Posted by FormulaBoat View Post
What controller do you plan to run, and is there proven data that an aftermarket tuning program such as EFI-L or HP-T can control them somewhat accurately? I think the aftermarket cams limit the VVT amount via spacer blocks in the VVT actuator, so their effect should also be somewhat limited but there should be gains nonetheless. Spring pressure can greatly affect proper VVT control as well, so get in bed with TSP if or when you buy and install it and follow their recommendation.

Sorry, I didn't answer your question, but I will be watching this post as well for the answers. I have the same engine going into a Colorado, also wanted VVT, but did not spend enough time researching proven control of the VVT system via an aftermarket tuning program, into an ECU operating system which did not have it for that specific year (stock 2009 E67 in Colorado 5.3L).
I'm running an E38 ecu and a T42 TCU. Both work flawlessly and I've been driving the car as-is with VVT, in it's current configuration. Yes, all of these performance VVT cams come with a Phaser Limiter kit, which I plan to use. I have HPTuners, but I'll be having my car tuned by a local reputable shop familiar with VVT tables and tuning a VVT vehicle.
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Old 03-12-2019, 06:37 PM
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It will likely make great power with that cam but at a price of more frequent service. Your going to eat up valve springs like mad with that cam, especially if you are running the stock L92 valves. Plan on swapping every 10k miles or so if you want it to be good. Or just get a cam with lift under 600 and go. Lots available now so long as you keep the split wide around 10-12 degrees that seems to be the ticket with the square port heads. Definitely want a soft lobe as well imo.

Unless its a racey focus deal, then go full kill and get crazy custom grind from TSP
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Old 03-12-2019, 07:48 PM
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Originally Posted by cam View Post
It will likely make great power with that cam but at a price of more frequent service. Your going to eat up valve springs like mad with that cam, especially if you are running the stock L92 valves. Plan on swapping every 10k miles or so if you want it to be good. Or just get a cam with lift under 600 and go. Lots available now so long as you keep the split wide around 10-12 degrees that seems to be the ticket with the square port heads. Definitely want a soft lobe as well imo.

Unless its a racey focus deal, then go full kill and get crazy custom grind from TSP
Thatís interesting. I havenít heard of anyone mentioning the need for new valves when doing this cam swap. Obviously, Iíll be going with tspís recommended springs, but I hadnít planned on replacing valves.
Can you elaborate? Also, what about this cam with eat up the recommended springs? Or my stock l92 valves for that matter?
Help me understand.
Thanks!
Nick
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Old 03-12-2019, 08:11 PM
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The springs take a pounding with aggressive cams. Most serious racers test spring rates after every pass its so bad with aggressive cams. There is a LOT of power to be made with aggressive cams but you really have to spin them up high to achieve the power potential and down low they are sluggish. As a result over the years I lean towards milder cams which give up next to nothing under 6500 RPM and dont require crazy stalls nor do they require super frequent valve spring changes. If you run a mild enough cam you can run the blue LS3 springs and they will last a good 50k or so miles maybe 100 pending use. So with cams its best to think about what you really want because there is a LOT of variance in performance vs user friendly manners. If your going for a bigger cam just be sure to get soft lobes, ask TSP or your preferred vendor, they will know.

Stock L92 intake valves are approx 110grams and the exhaust is around 75grams. LS3 hollow intake valves which are a direct droppin are also 75grams. They are made by Fererra
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Old 03-13-2019, 08:02 PM
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Originally Posted by cam View Post
The springs take a pounding with aggressive cams. Most serious racers test spring rates after every pass its so bad with aggressive cams. There is a LOT of power to be made with aggressive cams but you really have to spin them up high to achieve the power potential and down low they are sluggish. As a result over the years I lean towards milder cams which give up next to nothing under 6500 RPM and dont require crazy stalls nor do they require super frequent valve spring changes. If you run a mild enough cam you can run the blue LS3 springs and they will last a good 50k or so miles maybe 100 pending use. So with cams its best to think about what you really want because there is a LOT of variance in performance vs user friendly manners. If your going for a bigger cam just be sure to get soft lobes, ask TSP or your preferred vendor, they will know.

Stock L92 intake valves are approx 110grams and the exhaust is around 75grams. LS3 hollow intake valves which are a direct droppin are also 75grams. They are made by Fererra

Thanks Cam,
One of the main reasons I picked this cam is because it gives up nothing anywhere vs. the stock cam. Take a look at the dyno chart I linked below. It literally gives up nothing on the stock cam, anywhere in the range (sure its done with an L99 engine, which is still the same 6.2 as my L92, for all intents and purposes. You mentioned valve weight, and yes, the LS3 has lighter, hollow valves, but the L99, which this cam is designed for, has VVT and AFM and shares the same heavier valves with the L92, which leads me to believe this cam is just fine for my L92 valves ). Also, I did talk to TSP, and they didn't mention anything about needing to change/address my stock valves. It's my understanding that for a VVT cam, this one is relatively mild. They said it has good street manners, and some people have even run it on the stock converter, though they suggest a 2800-3200 stall converter to really get the most from the combo. Again, I plan to buy their kit that comes with their recommended springs, retainers, and pushrods. I'm not trying to build an engine that will need the spring rates tested every other time I drive it, and TSP gave no indication that would be the case with this cam.

https://photos.app.goo.gl/CfhQ6muXXB9ynhzS6

Anyone else have an opinion on this cam? I'm not trying to make a race car, and before the above input, I didn't think my cam selection was overdoing it.

-Nick

Last edited by nicke; 03-13-2019 at 08:21 PM.
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Old 03-14-2019, 08:59 AM
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Definitely your going to want a stall with that cam imo. You'll probably love it, just remember the valve springs are not going to last long. Plan on changing them every 15k-20k miles tops imo. Or not, your engine, your choice
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Old 03-14-2019, 02:06 PM
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Graph is exciting, but doesn't make sense to me. L99 is rated from GM @ 400hp. Graph shows 450hp. I assume TSP had long tube headers and a tune on it to begin with?

http://gmauthority.com/blog/gm/gm-engines/l99/
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Old 03-14-2019, 02:14 PM
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Originally Posted by FormulaBoat View Post
Graph is exciting, but doesn't make sense to me. L99 is rated from GM @ 400hp. Graph shows 450hp. I assume TSP had long tube headers and a tune on it to begin with?

http://gmauthority.com/blog/gm/gm-engines/l99/
Yea, you are correct. Definitely Lt's and I assumed either a tune or some other change to get that elevated baseline . Maybe just the deletion of the serp belt and accessories up front? I also bet TSP version has the deleted AFM, which the Gm version wouldn't (not sure just deleting AFM ads Hp though). I'm not sure what factors go into GM's rating, so I'm not sure what esle would be different. The performance increase is relative though, none the less, and impressive in my mind as well.
I love that they have a vid of the run:

-Nick

Last edited by nicke; 03-14-2019 at 02:27 PM.
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Old 03-14-2019, 02:27 PM
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Texas Speed is solid, they wont sell you short. Jason has a ton of experience in cam development but my issue is with so many guys chasing a number they give up SOOOOO much from their engine and tax their combo on tilt requiring a host of supporting mods for all things to function harmoniously. That cam vs a milder grind wont see a whole lot of difference in real world performance. From street light to light a racy cam will often fair worse than a mild torqy grind. Tight lobe sep, 570 lift and duration numbers under 230 will be a thrilling cam that makes power everywhere and you can go two routes; high lift for top thrill but frequent valve spring changes and valve guide wear etc etc or low lift for running WAY more miles without service or parts wear giving up maybe 20hp up top, maybe. Cam only at best your looking at 60 or 70 hp at the extreme and 30-40 on the low end of cams. Yet the differences between the two in terms of driving behavior will be extreme. The cam is the brain of the engine. Big cam = high strung. Even a stock type size cam with a much better lobe and overlap will wake the thing WAY up.

Anyways back when we were all chasing the perfect cam GMHTP did a great article that super chevy saved. See link


http://www.superchevy.com/how-to/eng...ft-comparison/


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Old 03-14-2019, 02:59 PM
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That IS a good article! A lot of those cams aren't around anymore but the basic info is still good.
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Old 03-14-2019, 03:12 PM
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Originally Posted by cam View Post
Texas Speed is solid, they wont sell you short. Jason has a ton of experience in cam development but my issue is with so many guys chasing a number they give up SOOOOO much from their engine and tax their combo on tilt requiring a host of supporting mods for all things to function harmoniously. That cam vs a milder grind wont see a whole lot of difference in real world performance. From street light to light a racy cam will often fair worse than a mild torqy grind. Tight lobe sep, 570 lift and duration numbers under 230 will be a thrilling cam that makes power everywhere and you can go two routes; high lift for top thrill but frequent valve spring changes and valve guide wear etc etc or low lift for running WAY more miles without service or parts wear giving up maybe 20hp up top, maybe. Cam only at best your looking at 60 or 70 hp at the extreme and 30-40 on the low end of cams. Yet the differences between the two in terms of driving behavior will be extreme. The cam is the brain of the engine. Big cam = high strung. Even a stock type size cam with a much better lobe and overlap will wake the thing WAY up.

Anyways back when we were all chasing the perfect cam GMHTP did a great article that super chevy saved. See link


http://www.superchevy.com/how-to/eng...ft-comparison/

Thanks Cam, but now I seem to have more questions. If the cam I suggested above is in fact high strung, that's not what I'm after. I'm not willing to be replacing springs every 20k miles on a 95% street driven car. TSP didn't give me any indication that would be true with this cam, so that would be new info to me.

I was first looking at their stage 1.2 cam, which they say is designed to work with a stock converter, and has a slight lope at idle but mild mannered on the street.
It's specs are 223/233, .629"/.629", 114 LSA

Just like the 2.2 cam I referenced above, it provides increases across the board from the stock cam, but it has the same lift at .629"/.629". If this lift constitutes a "high strung" and therefore, frequent spring changes, why would TSP have designed it to work with a stock converter (someone obviously not focused on building dirvability sacrificing, performance focused cam)?
You know of a cam that gives better performance then either of these with VVT under 6k rpms?
Again, I'm not chasing the max numbers, I want the best and flattest numbers from say 2k-6k and I'll happily give up top end. The reason these cams were appealing is because I't didn't feel like a trade off. I got to have my performance increase down low, and bigger numbers up top to boot.

Here's the run and chart on the 1.2 cam.

Thanks
-Nick
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Old 03-16-2019, 12:07 AM
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Am I barking up the wrong tree?
Is there a VVT cam that packs all the performance gains down low, say under 5k rpms?

Link?
Thanks
Nick
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Old 03-16-2019, 01:25 PM
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First off lets address the VVT. With a solid cam you can only advance or retard the events, you cannot change the dynamics or separate the int/exh behaviors independently with the GM VVT system. While this is a nice little feature it bears no relevance to the cams profile, manners, or overall performance. The VVT av/retard helps to extend the cams range slightly and most of all can be used to greatly reduce pumpong losses during coast and low throttle applications which increases fuel mileage which is the primary goal for GM's use. The difference between a VVT cam and a non VVT cam peak power wise will be very close, if not the same, it really depends on the cam and the tuner especially to make the most of it.

As for high strung? Perhaps I should have phrased high effort. High effort cams place considerably more strain on the valve train than low effort cams. While you are 100% correct with the rect port heads performance cams give up little to no bottom end WHEN RUN WIDE OPEN the driving manners will be radically different between the milder versions up to the wilder grinds. Mild/wild is also relative to each of us. Some of us are fussy to driving manners and some are not so most of the terms and satisfaction of cam performance and behavior are all biased because of that making picking the right cam from opinion hard to grasp. As a general rule cams in the 210 duration range are mild, 224 range are mid, over 230 getting into the hotter range. This is a general bolt on car type guide for stock cubes as bigger cube motors need more cam to fill the cylinders so cam profile and engine size are correlated.

Being a HotRod car that wont see daily use the cam you picked will be tons of fun but imo without a stall is not going to be fun to cruise around in. If you want a torquey stock stall type cam I like the comp 210/224 VVT grind it can be run with the blue LS3 springs and will put down maybe 410whp or so with a ton of snap and fun torquy behavior yet still pull to 6500 RPM well. If you want to get a stall and use some good srpings like the PAC1218 or psi1511ml then go for the TSP cam. Just be sure you also add long tube headers, good exhaust, good large intake 4" with LS7 maf card, decent injectors as well as hardened push rods and a good stall. Seek out a quality tuner and it'll ROCK
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Old 03-16-2019, 06:00 PM
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Originally Posted by cam View Post
I like the comp 210/224 VVT grind it can be run with the blue LS3 springs and will put down maybe 410whp or so with a ton of snap and fun torquy behavior yet still pull to 6500 RPM well. If you want to get a stall and use some good srpings like the PAC1218 or psi1511ml then go for the TSP cam. Just be sure you also add long tube headers, good exhaust, good large intake 4" with LS7 maf card, decent injectors as well as hardened push rods and a good stall. Seek out a quality tuner and it'll ROCK
Thanks Cam. This is all really helpful for me. Is this the comp cam you are referencing? http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=1606&sb=2
Also, I already have Long Tubes, 2.5" dual exhaust with X pipe, nice 4" intake, nice maf. Are you saying this cam from comp will be more snap and torque than the the 1.2 or 2.2 VVT cam from TSP given the the mods I already have in place? If so, that's exactly what I want.

-Nick
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Old 03-18-2019, 11:22 AM
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The cam you picked will rock with a stall. I dont think that cam is going to be a ton of fun on the stock stall. Especially the huge 4L80 converters they are not big cam friendly. If you get a converter Im a fan of buying a GOOD converter, expect cost around a grand for this but worth every dime in my experience. The cam you chose and a GOOD converter ( Coan, PTS, Pro Torque etc ) and you will LOVE that combo. Just keep an eye on the valve springs is all, they are not a lifetime part in this situation.

If your looking for stuff in a cam, and rip around without a ton of concern? Then yes that cam you linked will be heaps of fun even on the stock converter. Thats not to say that a good aftermarket converter wont also improve on the smaller cam too, even with the stock cam the stall upgrade will be major tire sizzle improvements. But if going cam only and leaving the stock stall that cam will be fun. Maybe another step up? Maybbbbbee but give TSP a call and see what they have to say on it. Over time with all the dyno charts here and there the game of making the most power has certainly taken over the goal of making the most fun car to drive. Tricky thing to get done in one go, theres often tweaking and with cams its a big tweak as its pricey to swap cams just for the right fit, and its a good bit of work too so putting thought in up front is smart. Its also a great idea to go for rides in others set ups to see.

All that said? whatever cam or combo you spec you will be just like the rest of us after a year or so, and looking for MORE POWER hahaa welcome to the chase
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Old 03-18-2019, 11:52 AM
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Thanks Cam.
Really helpful stuff.

If I get one of these hotter cams, I'm looking at getting a Yank SS series converter, as I've heard good things about their street manners.

Again, thank you for the input!

-Nick
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Old 03-18-2019, 11:58 AM
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Yank has a good rep. If you speak with them ask what the front cover is and what stator is used. Thats where the $ in stalls is. Furnace braze blah blah is all fine and dandy but the cover and the stator are the mojo for more gogo so if they cant give you specifics? Your buying a "saturday night special" which is a loosened up stocker. Better, but FAR from a real stall upgrade. When the converter is RIGHT? You stab the gas and the world rotates under the tires

Happy hunting glad to help. Go big if you can swing it, and be sure to add cromo push rods to that recipe as well. Check the usual lifter wear, trunion, rocker tip, valve stem wear etc. New LS2 timing chain always wise. Stock VVT oil pump is fantastic btw so run it if good. New gaskets always wise. Blah blah Im sure you got that sorted by now. Nice engine choice too btw, your gonna love it
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Old 03-18-2019, 01:30 PM
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Thanks Cam, yep, I'll check those items out for sure.

Yea, even in stock form, I love this L92. I've had the swap completed for a few years now, and I've been driving it in my 65 impala ss and couldn't be happier with the setup.
Now, its time for a little more pep.

Slippery slope, I know. ;-)

Thanks!
-Nick
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