J-Rod

Do you realize how old the 3.8 design is and how poorly the stock intake port flows? Buick simply used what htey had and built stuff around it, but the bottom end of those motors isn't anything special, as I said, the intake port pretty much sucks, in all honestly there is nothing fantastic about the inherent design of one. Slaaping a turbo on the motor doesn't make it more efficent it simply crutches an inherent problem.

If thats the way you see it, thats fine. Its wrong, but if you see it that way thats fine. I.E. even with a turbo the intake port sucks. ITs not any more efficent, you have simply crutched the issue. As an example, I have a set of Aluminum heads for my GN that flow way better than a prted iron head stock. I had them ported even furhter, and they flow WAY better than even a ported iron head. Are you going to say that the stock head is just as efficient as my ported heads. The answer is no. Remember that boost is also a measure of restriction. You can't build boost until air backs up. The only reason for needing boost is to overcome a limitation of an engine or a port. If it is effiecent enoug those things aren't needed. You aren't making a motor more effiecnt simply covering up an issue (you can't amke the power you need N/A).

Ther eis a bit more to it than just uploading a SD tune and calling it a day. Tuning combos requires more tim than a regular LS1edit. In most cases it requires the car being under a load with an Eddy Current dyno. I watched cars being tuned over there. Its far from plug and go...

Thats fine, but why are you in here bashing everyone who doesn't want a Z06 cam. You call stuff old school ,and basically criticize everyone who doesn't see things your way. You answered your own question you want a Z06 cam, or a GT2-3, or a TR Old Man cam.

Ed already tried to explain it. There are tradeoffs. You've got mildly ported head, and headers. If you want a stealth machine you will either have to further improve port flow so you can reduce the ammount of duration required of have a power adder like a turbo charger or superchager to overcome the limitation of your port. You already have a TR224. I don't have your flow numbers, etc... but you get into the issues of using a smaller lobe 218 or 220, and then you have to play with trading lift for duration. Also, to optimize your car, you might end up going with a 224, but with a narrower LSA from using more optimal valve events. Again, you'll make more midrange power than you would on a 114LSA, but he tradeoff is more overlap, and probaly a bit more lope at idle.

If you really want a custom cam, it can be done, just don't expect someone to give you the specs for free... There are plenty of lobes out there...

Grant B

Do the aussies replace valve springs as often as us? I don't understand why springs with a stock Z06 cam could last indefinitely compared to a cam with 20 to 30 degrees more duration and .05" more lift.

FASTONE

This just keeps going and going

SilverSurfer

J-Rod, efficiency has nothing to do with the need of a power adder. The basic principle of using a turbo from the factory is to have a smaller cube motor act like a big cube motor without the trade-offs of poorer gas milage at part throttle and increased emissions. Lets look at the 346 cid LS1, it's a pretty efficient motor wouldn't you say? Now compare it to a Ferrari engine with the same displacement or a Mercedes or Porsche or Lamborghini. How it pales in that comparisson. Does that make it a POS like you said the TR 3.8 is N/A? So the intake port doesn't flow all that great, it's how an engine uses the fuel and air supplied that makes it efficient or not. The 3.8 is a very clean burning engine, in fact it's been used for emissions tests done by independent labs. That's what happened to all those long and short blocks that were siting around after the turbo 3.8 saw it's last days in a production vehicle. And yes I do realize how old the 3.8 is that's why I called it an oldie but a goodie, cause it's still found in many of today's GM cars unlike Ford's 5.0 and GM's SBC1 and LT1.

A power adder increases the volumetric efficiency of an engine, thus that engine is now more efficient, irregardless of what the intake port flows N/A.

I realize that with SD there's a need for tuning, never said they uploaded it and called it a day. My point is that they had a base tune which we don't. I've always believed that a good SD tune makes more power and can be more civilized than a MAF tune. Less variables introduced by the MAF. The TR guys are doing it aswell with the SD Max Effort chip. Better throttle response and more power has been reported.

I'm not criticizing, I'm pointing out that we all have different likes and dislikes when it comes to how our cars idle. A 256/256 cam does not idle like a stocker. You might get it to idle at 850 RPM but it will chop and buck, more so than a cam on a 114 lsa. Even the LPE grinds are on a 112 and larger LSA, and John Lingenfelter's view has always been "area under the curve".

The LS1 from the factory is a highly refined engine that produces good bottom end torque, not L98 or Lt1 torque, and great midrange and top end. That's the way it was designed. So why stick a cam in it that is going to turn it into a stump puller? GM realized that those engines are a way of the past and moved into a direction similar to what the Europeans are doing with their performance cars. Looking at what the Z06 Vette can do, I think they've succeeded. It's not Ferrari power levels but it also doesn't cost $100+K.

So if a 256/256 cam on a 106 lsa in a Chevy small/big block (includind the big block since it's a big block grind) isn't old school, than what is? Ya think no one's ever tried it in a FI car before?

Cstraub

iTrader: (1)

Silver, the 3.8 of today is not the same as the "oldie". It shares much of the LS1 technology.

Chris

J-Rod

I would agree that a turbo can be used to overcome limitations in a motor. But, it still doesn't change the fact that many engines are not efficent, and in the case of the TR, it was a band-aid to fix an issue. Its a quite effective one, and honestly I love the way the car runs. But, lets not kid ourselves and call an intake port efficient when it will only flow 165cfm when its fully ported...

The Ls1 is particualrly efficent when you look at bsfc, and when you look at the port design and airflow, along with the fact that for instance the Z06 is a ULEV motor making 405HP, and is the only motor in the sports car realm to do so. You cite Ferrari, Mercedes, Porsche, and Lamborghini.

Ferrari makes short stroke big bore motors with multivalve heads an Ti connecting rods. The efficency of those motors relates to valve curtain area from a multivalve head. It lets the motor breathe.

In fact if you look at most of the marques you listed, not one of them is going to be a 2 valve OHV motor like the LS1. Gm experimented with OHC motors (ala LT5) and found the cost to be high, and more complex. They were able to meet the target HP goals much cheaper the the GenIII motor. I was fortunate enough to see one of the early gen III mules when it was making 400 HP. This was just after the LT1 had appeared.


If you don't think for its cross sectional area that the LS port doesn't flow well, you are sadly mis-informed. That is one of the good things about this motor is that for its size the port is pretty darn good.


I had one of those engines for several years as one of the labs no longer needed it. Another reason it was used was because it was in a lot of cars, and it made a good test platform. Those engines weren't used in many cases after the cars were out of production as they couldn't provide relevant data. And, as stated, a current 3800 and a 3.8L like is in my TR have quite a few differences. Its like saying a GenI SBC and an LS1 are the same motor. They aren't...

No, all you've done is make the motors specific output greater you haven't made it more efficient. Thats like saying nitrous makes a motor more efficient. Its not more efficient, you've just increased specific output of the engine by increasing the ammount of air/fuel in the motor. But even then, you will run into a limitation in the port or intake design at some point. Look at a recent test in HRM about how much nitrous a stock headed SBC could take. They finally reached the point of reversion on the motor where the intake charge began to fog over the top of the carb. The motor just can't take any more in no matter what you do. Now, you put a better head on that car, and a better intake, and that point moves. You have tehn increased the efficency of the engine. In the case of a TR, the stock iron heads suck. That leaves going to an aftermarket head or stgII head.

Thats not what came acros in your post. You made it sound like they hadn't really done anyhting other than copy a GM tune which is not the case.

I talk with Steve (the guy who does the SD stuff) regularly. I have a 16POS max-effort, and may move to SD at some point. The Aussies have found the same thing, remove the MAF,and throttle response gets better. It interesting how it is in different camps. Think about all the Mustang guys who converted from SD to MAF, and look at how many folks in the Mustang world play around with those huge MAF meters...

John was a great man. I highly respect every thing he ever did. I have friends who had his stuff from way back in the day. Even in the L98 stuff, John did some fairly big cams. Lets look at what LPE was after. LPE was after making the most power in the area where the engine spent the majority of its time. I'm after the same thing with this thread. John also made sure that his packages were emissions compliant, and that the cars had 0 idle and drivability issues. As we should all know, the area of tuning has come a long way. The LPE target market has always been the guy who wants an extra 100HP, and all the manners of a stock car. But even some the current LPE packages have some chop to them. I drove an a LPE H/C car recently at a shootout the car had an off-road exhaust, and a GT1 cam in it, and there was no way it idled or sounded close to stock. I'm not saying thats a bad thing, I'm just stating the facts.

Lets also look at the vaunted Z06 cam. Its a bit soggy down low, but comes on strong @ 4000. Even it has some chop to it. If you listen to one with the stock Ti's and the cats, even then it has some lope not alot, but some. You throw some long tubes on it, and delete the cats, and the car has a LOT more lope, and a bit of chop to it. What I am saying is how "stock" your cam sounds not only relates to the cam, but also to your exhaust selection, etc... Look at the folks who buy the MTI stealth cam and have loud exhaust, and then complain the cam lopes.

The LS1 makes more more torque than an L98. The reason that motor seemd like a torque monster was that the motor ran out of steam over 5200 RPM. I know, I had an 88 Corvette. It ran 14.67 stock, and 13.89 with a test pipe, chip, flow masters, and timing turned up. My stock Z06 makes 200 more HP and runs 11.60's

GM did exactly what they have always been good at, that is designing a motor that is simple, can be built cheaply, and make the HP targets they are aiming for, while managing to reach the levels of efficency that the govt. requires. The LS1 has plenty of torque. Look at the 6.0L truck motor. I'll always take a motor that makes power down low rather than one you have to rev the snot out of.

J-Rod

Its not a big block grind. It was a lobe designed for BBC marine aplications where you need to run a lot of RPM for a long time with a heavy valvetrain. Hence the reason theose guys were using it. No broke springs, and no durability issues.

Have you read any of this thread yet? If so, have you just missed the central point which is the proper selection of valve events?

That 256/256 lobe has about the same lobe area as a 232/232 XE-R lobe. Again, I'm not pushing this cam for everyone. Look at what hose guys have to say. Most of them are runing 232/232 108 cams in daily drivers and they have good drivability and manners. Anything more has an edge to it that some folks don't like.

What you seem to basically be missing here is that using X lobe and Y LSA is not somehow reserved for one engine (like a BBC or an SBC). You can run a TR 224/224 114 in an LS1 or a SBC if you want.

Again, the main issue comes down to selecting the right cam for the engine. If you are unwilling to optimize your combination any further than a stock cam or have restrictions based on some personal preference, than thats your issue. You run into a wall at some point that can only be addressed by getting more air in your motor which means better heads or a power adder.


As I said, the Z06 cam is a perfect example of what happens when you spread LSA. You take away bottom end power and push the power band way up. If you spend the time selecting a better cam, not only will you make more power down low, you will make the same power up top. Yes, that cam will have some overlap, it may lope just a bit, but thats what you tradeoff to get that.

Another thing you have to stop looking at is peak HP. Look at avg HP. You'll find a better designed cam will have a fatter and flatter curve. I'll take a cam that is 20 HP and 20 Lb-FT more over a 3000 RPM range over a cam that picks me up 10 HP in a 1000 RPM range.


Now, you've made your point perfectly clear you think the best thing out there is super wide LSA cams that force you to rev the snot out of a motor. I and many other folks disagree with that notion. It is also not supported by the facts. If you want to go run ProStock, then stick with super wide LSA as your main desing criteria. You've made it clear that you feel like anything other than a stock idle is a bad thing.

I've posted a video of a car running with one of these "impossible" cams. To me, it seems to idle pretty darn good. So anyhow, I think we all know where you stand even if you point of view about what is "old school"or what is right has no basis in fact or reality. In fact to sum it up you are pretty much the poster child at this point for most popular misconception about cam selection at this point.

Like I pointed out up top with the cams from David Vizard. He went from a bigger lobed cam on a 114 (278/290 114LSA 56 degrees of overlap) to properly selected lobes of (272/278 108LSA 58 degrees of overlap). He made more power across the board which is more avg HP, not just some peak HP number.

That cam won't have a stock idle, but it will have good manners and good drivavbility.

I think we all understand your points Surfer. But the "yes it is, no its not" is getting old. You keep making claims but have yet to back anything up with anything other than your subjective opinion. If you have something to add that is based in fact then please post up. Otherwise can we please get back on topic. Alternately if you want to start your own thread and post your world view then feel free.

Ed Curtis

AMEN!



Ed

SilverSurfer

Chris, actually the LS1 shares some of the technology of the 3.8, such as the intake manifold design. lol

J-Rod, I guess you're right. Nothing I've stated is based on fact. It's obviously a misconception that a wider LSA cam will have a smoother idle. Must have pulled that one out of my *** or something. It's also obvious that the Aussies are dumping alot of fuel with their tune to make those cams act civilized since the guys with the "street/strip" 242/242 cam are reporting using 19L/100Km, roughly 12 miles per gallon. Yet the Colonel reported getting better milage with his Stealth 2 cam. And his 3550 lb Camaro has gone 11.2s at 121 mph on a DR. https://ls1tech.com/forums/dynamometer-results-comparisons/101464-mti-stealth-ii-cam-stage-ii-ls6-heads-makes-422-7-rwhp.html

Whatever......

PS: Back in the mid 90s guys went in the 9s in 3400 lb TRs with those poor flowing facory 3.8 heads and that tiny MAF and stock computer. WOW, that's some POS engine and that turbo is some CRUTCH. There were 7 second TRs back in those days, 7-8 years after the intercooled turbo 3.8 came out, and there aren't any 7 second LS1s today, 7 years after it's introduction. Must be cause of these damn wide LSA cams. Guess you and ED will show us how it's done. LOL

J-Rod

As has been stated ad nauseum. If you need an overly wide LSA to get the car to idle, then the duration selected is too big for the job. I.E. its a poorly designed cam and you are band-aiding your poor choice of valve events. Thats not to say if all you are after is a stock idle you can't get there with a wide LSA, you are simply leaving a lot of power on the table and un-necessarily (unless thats what you want) moving the power band way up. If you want a stock cam, great. Put an even smaller cam that stock in your car. If you think LSA is what makes a great cam spread the LSA to 120 degrees and report back to us on your stellar performance.

As for how tuned cars run. I recently caravaned to the Z06 Fest. I got 26-27MPG on my stock car. A H/C car with a big cam that we drove with got 31. Fuel milage has a lot to do with tune. You can tune a car fat or you can tune it lean... Tommy's car with a 4.10 and an X3 makes over 22 on the freeway running 80 all day long.

Hmmmm where to start. I live in Houston. Who lives here in Houston. Ummm folks like Lawrence Conley, and Gene Deputy. Folks that I have spoken with at length, hung out at the track with, street raced with, and generally had more than just a passing association with.

Maybe you remember them from the heyday of GN performance. Your recollection of the 90's is a bit skewed as at that time Black (Lawrence's car) had M&A aluminum heads on it. When they went to Tweaked they switched over to Buick Stage II heads both of which are far superior to a stock head.

Here is a bit of schooling for you champ. Take a Stage I motor and whatever power you make @ 25psi with the best aluminum ported stock style head, you can make the same power @ 10psi with a stage II motor. So don't throw this 7 second on stock heads at me, thats just plain B.S. Also, those cars were nowhere near full weight. Even the car running in the 9's today like Jason Cramer have had a bit of time to get those combos sorted out. They benefit from turbo technology we didn't have in 94, and thus they go faster.


Also, the only 7 second 3.8 variant powerplant at that time was Buddy Ingersol's Stage II based turbo car in 1986 which was outlawed by NHRA for Pro Stock. It wasn't til later that anyone tried getting into the 8's, and at that time it was Duttweiller trying with with his big twin turbo car, and Tweaked II when they went up to the big Thumper turbo. Also, the fast cars didn't run a stock computer, or if they did, it required add on injector setups, etc... They ran aftermarket TB's sheet metal manifolds, etc... Far from a stock motor.

Again, if you want to cite some specifics please feel free to post up who went what and when... I was on the gnttype.org distro list for several year along with being a member of Turbobuick.com again your claims are basically complete fairy tales... You are about a second off on your times. I remeber when Lawrence was taking Tweaked II which was a lightweight car (before it was tubbed) and working out the issues getting it into the low 9's. That was 1994. I was also at the second Fastest Street Car shootout when his water pump pulley fell off the car and he was unable to finish.


BTW, W2W just finished an LS1 motor for one of Pete's buddies in Australia it makes 1500HP. Put that motor in a 2200 lb Pro Stock Chassis like Ingersol's car, and you go well in the 7's...


BTW, here is a list of what in our GN
109 block .020 over
Stock Crank
Stock rods
ARP fasteners
JE Pistons
RP309G Hyd Roller cam
BGC Intake
BGC Upper
AccuFab TB
72# injectors
16POS Max-Effort Chip
ATR S/S Headers
THDP
Loveridge Girdle
Billet main caps
GN1 heads (Ported by Lump @ NRC)
Precision 4000 Stall with O Pump
CAS FMIC
CAS Radiator
Precision TA64e with fast spool housing
Customer oiling system, plumbing, and coolers by me...

SilverSurfer

You are truly an amazing sort of person. I love how you pick and chose what you WANT to read. Never stated there has ever been or ever will be a 7 second stock headed TR. DUH..... Must be why I said 9s with factory heads.

School this.......From the GNTTYPE.org archives.

Curtis Allen Lum: LONG LIVE KING KEN
Date: Mon, 13 Nov 1995 00:18:56 -0800
Subject: LONG LIVE KING KEN
From: Curtis Allen Lum

NEWSFLASH!!! I JUST GOT BACK FROM THE HI-TECH SHOOTOUT IN BAKERSFIELD, CA.
IF YOU HAVEN'T HEARD BY NOW, KEN DUTTWEILER JUST SET NEW RECORDS FOR FASTEST/
QUICKEST GRAND NATIONAL. KEN CLICKED OFF A 7.84 @ 185+MPH!!! WOW!!!!!!
CONGRATULATIONS KEN, YOU ARE THE KING!!!

"IMPRESSED" AKA CURTIS LUM

P.S. MRS. DUTTWEILER IS ONE OF THE NICEST PERSONS I HAVE EVER MET. YOU ARE A
LUCKY MAN KEN!


And here's some more schooling for ya......back it the day (don't remember when but I could do some "research" for ya) Tweeked II (guess which Texan owned that one) a CHEVY big block powered twin turbo 93-97 Camaro got spanked by Kenny D with his twin turboed BUICK V6 Olds Calais 2 out of 3 times. Both cars ran in the high 6s.

-=Merlin=-

Alright gents put your dicks away, lets get this thing back on track.

The following is an email I sent to Mr. Rawls, 93 Pony posted a link to his website in one of his previous posts, to try and get emperical information regarding the topics in this discussion.

this was his response

The same information and principals that have been repeatedly stated are reiterated by him. So lets see, there is Ed Curtis, Cstraub, 93Pony and Mr. Rawls all emphasizing the same thing. A fluke?

The real kicker, for me at least, is the fact I worked in an engines lab and had access to an engine dyno with an LS based engine on the stand. Wish this thread popped up a couple years ago, pretty sure I could have convinced my mentor to explore this stuff on his dime.

Thoughts on Mr. Rawls response?

SilverSurfer

As far as the gas milage thing goes, read your own posts before you start telling me about what your z06 and your buddies G5X3 cammer get on the highway. It would seem your buds down under can't match the milage these wide LSA cammed cars are getting.

"The 242 will destroy your fuel economy big time expect around 25 l/100 km around town. The 242 has a lope like a mo fo and sounds as angry as hell."

"I'd agree that the 242 isn't a recommended daily driver, but for a weekend car it rocks! I'm running a Grand Am cam 239/251 on a 106lsa. I like it. Average fuel consumption is steadily reducing - have it down to 19l/100km, driven quite hard. So far car has made 390rwhp, is an A4, with the converter unlocked. Havent redynoed after changing to D/F 1-3/4 headers and twin 3" system, but engine revs noticably harder to the 7100rpm redline"

Point being..........to make a big lopey cam act civilized at idle and part throttle you have to dump alot of fuel. Make sense now?

Maybe you should change your name from J-Rod to Nimrod, and I'm not reffering to the dictonary meaning of that name champ.

Pro Stock John

iTrader: (34)

So he is saying that folks make global assumptions and apply them to all engines? What is he suggesting that folks do differently?

I think that generalizations like many in this thread comparing genIII stuff to SBC's and 5.0's are interesting but fall short. Cylinder heads are a major key and they are being glossed over.

J-Rod

A twin turbo Stg II motor goes 7.84. As I already said, Ingersol did it with a single turbo in 86. whoopie. Whats your point. Furthermore,I don't think the car was @ 3400 either.

Go ahead an humor yourself and go search the archive for all the 9 second cars with stock heads, computer, etc... and report back... I'll be sure to put my life on hold waiting for you.

As for Tweaked II, its a BBC with twin turbos. I would hope it would run decent... Heck I saw the car several times getting built. Racer7088 (Erik) has done work on the motor I believe...

It still doesn't make my point about the heads on a GN any less valid. If you've ever worked on a set of heads before, you'll understand this. If you've ever seen real flow data, you'll understand this. The 3.8 is what it is. I own one, and I've spent a lot of time in it.


Merlin, thanks for your thread, and trying to get the thread back on track, hopefully we can get there. I need to look over the comments and post up.

J-Rod

Yes, I copy and pasted the comments of some actual owners of those cams rather than some keyboard warrior without clue whose never seen one.

As for my mileage and that of others, thats what I saw firsthand, so I reported it.

As for what it takes to make something idle, there are plenty of ways to make something idle, and to tame down idle.

As for the name calling, whatever. As soon as you contribute something meaningful to the thread it would be greatly appreciated.

Here I got you something...

SilverSurfer

Well well well.....As I was typing my next "cam" related post to this topic I see that Nimrod has made a new post. Good way of admitting you were WRONG. Just admit you were wrong and I'll call you J-Rod again. LOL

Anywho.....A point that none of the cam experts have touched upon is this. Have you ever designed a "custom" cam and it didn't perform as expected? Maybe fell short of even what a "shelf" cam could do? Hmmmm......? Like the song goes "It happens all the time......". Go on, say it isn't so. Hey, I can admit my car's not all that fast for what's done to it, why can't you guys admit it's not all cut and dry?

SilverSurfer

LOL Nimrod, don't go putting your life on hold for me.

SilverSurfer

Sure there's ways to tame a cam, they're called fuel and timing. If you notice, I listed fuel first cause that's the best way to tame it. Timing can only do so much, fuel can do more. Oh, there's a third way...... and I'll make it rhyme for ya

The third way
Is LSA.

Pro Stock John

iTrader: (34)

I have no idea why you guys are singing the praises of the LC2 (GN engine). It was a decent V6. Current V6 engines make more power.

Let's not forget what the stock cam specs are:

LS1 Camshaft Specifications
1998 - 2000 Fbody
202/210 int/exh @ 0.05" duration
0.496" / 0.496" int/exh lift
116 LSA

2001 - 2002 Fbody
197/207 int/exh @ 0.05" duration
0.467" / 0.479" int/exh lift
116 LSA

2001 LS6 cam
207/217 int/exh @ 0.05" duration
0.525" / 0.525" int/exh lift
116 LSA

2002+ LS6 cam
204/218 int/exh @ 0.05" duration
0.551" / 0.547" int/exh lift
117 LSA

GMPP Hot Cam
218/227 int/exh @ 0.05" duration
0.525" / 0.525" int/exh lift
112 LSA

GMPP ASA Cam
226/236 int/exh @ 0.05" duration
0.525" / 0.525" int/exh lift
110 LSA