All right. What's the tightest LSA for a TPI motor. I have heard that it can't get to tight. Or is that just with out a tune. I am looking at getting a comp Cams Thumpr cam http://www.jegs.com/webapp/wcs/store...0002_672928_-1. It sounds like what I want. I am not really concerned about it "Not being optimal for my motor and there's better out there". This motor is a fun motor. It's for a play car. And there is another motor waiting to go in it after I finish up the car. Can't put a 500 hp/tq motor in a stock drive line car now can we. So all I pretty much want to do is this stock 350 TPI with this cam with K&N's and headers with no cat and a slp loudmouth exhaust. I'll probably do ignition also. Till I finish the car up. So what I basically need to know is will this cam work even if I have to get a tune. Thanks in advance for all the help!! Adam :-)

 

that cam sounds way to crazy for a 350 stock TPI motor. its bigger than the CC306 cam and that cam is BIG. You should hear it in a LT1 car.

that thumpr cam is 235/249 with .527/.507 on a 107 LSA. sounds more like a carbed race motor cam.

it will be very tough to tune that on a stock TPI 350 motor. i'm gonna say get something else.

if you want something big that will thump around and be a fun car, CC306 is all the bigger i'd go but i'd do an intake swap of some sort. IT WILL need a computer chip tune to run right. once tuned i'd expect somewhere around 300-340whp depending on the intake setup you run. stock TPI may see 300whp where a HSR or something may see 340whp. LT1 cars have been known to make 350-360whp well tuned on stock heads/internals with just supporting bolt ons

else i'd get something on a 112 lsa with duration in the low 220's. comp cams 503 cam would be a nice big cam for a TPI. more "tuneable" too.

 

OK then. If that's to big what about the smaller thumpr cam http://www.jegs.com/webapp/wcs/store...0002_672927_-1.

And I also read in a cam and valvetrain book for sbc that gave me this idea first. Basically you just take what ever cam and cut the LSA 4 degrees. In the book he had a Comp Cams XE 268h with a 106 LSA instead of the 110 LSA. He said it was the overlap that gave it the sound. Most people would get the XE292 just to make sure they had the sound. But they would kill the driveability of the motor. This way you still retained the street driveability of the motor but have the sound. And that's what I am looking for. I'll see if I can scan that part of the book in tomorrow. And thanks again for the help! Adam :-)

 

cutting the LSA does increase overlap and definately will give you that rough idle sound. but 106-107 is very low. I dont know anyone that low. I think i have heard of a solid roller on a 108 in someone's combo before, but those thumpr cams are fairly large for a TPI motor and the lsa is just to tight in my opinion

the smaller thumpr cam reminds me of the TPIS ZZ9x cam which i think was 226/240 or something like that. that could work but i dont think i'd do it on a 107lsa but more of a 112-113

trust me tho, that duration on a 112 or even 114 LSA will lope around at idle on a L98. but its easier to tune on the higher LSA

 

As far as non-OE cams I've run a 110, 112, and 113 LSA and by far the 110 was the hardest to tune... and it was a small cam. The 113 is the biggest cam I've run and it runs better than the 112 did (ran better right out of the box too) and it has ~10 degrees more duration and a lot more lift. However, running a 107 will get you the sound you're looking for... its just going to be a total PITA to get running right. How's your tuning skills?

 

Tuning skills? What's that. lol. I have none. lol. I have been wanting to get into it since I have two cars to play with. But it's hard making since of all that stuff. Maybe one day. But not anytime soon.

Well how hard would it be to get a tune on the 107 LSA with a TPI chip. Cause I really want that sound. Is it even possible to get a 107 LSA to work with a TPI? I was just going to send in the specs to someone to get a custom chip done just so I can get the car to start and drive it. Or I was looking into doing the OBD2 setup. I have a friend that is doing that on his car right now as we type this. Would that be easier to tune? I could just use the money that I was going to use for the chip and sell the stock 350 TPI setup(Have a spare 350 intake) to get the parts I need for that swap.

Also. My IROC is going to have a t56 with at least the stock 3.27 gears till I get around to the other rear. Then it will have 4.10's. So I should not have to worry about not having that big of a stall or gears.

I'm going to try and find some sound clips of those cams you guys mentioned though. Like I said. This motor is just temporary till the big boy gets done. If this motor runs at least as good as the stock motor. I'm fine with that. I have also put all these cam specs on the desktop dyno on the computer and the thumpr cams do make a good increase. Not much but it's better then stock. I think that the smaller thumper cam would be better off then the bigger one I posted. The small thumpr makes about the same as that comp cams 503 you mentioned. Again, Thanks alot for helping me with this guys! I appreciate it!! Adam :-)

Oh, Here's that article from the book.

 

the 503 cam is a good cam. 112 lsa i believe so it will run on stock tune with mass airflow cars. it will need idle tuning cuz it should run rich and then tuning everywhere else...but i'm sure if you send those cam specs off to one of the more popular mail order chip sites, they can get you close. ALOT closer than one of those 107 lsa cams. that will need a very good tuner and a dyno and wideband o2 sensor. even then with so much overlap, the o2 sensor may not get accurate readings

here is a CC306 on a LT1
http://www.lt1engine.com/media/music...php?song_id=47

 

The cam I had was very similar to the Comp 503... close enough I'm sure you couldnt tell even measuring the two with a mic. The XFI cam idles and runs better. You wont be running it on a stock tune with a MAF either, the cam has too much duration for the stock programming to handle. You can order a chip, but it will be off too, as I found a lot more power and driveability tuning it myself. I even sent a datalog and had one reburn and was still unhappy until I took the matter into my own hands and thats from a relatively widely accepted tuning/parts company. That 107LSA with that kind of duration is going to be a handful for anyone and mail order is going to be difficult at best to get a reasonable tune of any sort.

I'll post up a couple sound clips in a few. Might be best to right click, save as (slow server)

Similar to 503, through the exhaust (recorded from the front of the car, about 10' out, muffled by geardrive noise)
http://home.earthlink.net/~wtomfoster/gp.wav
Same deal, but open headers
http://home.earthlink.net/~wtomfoster/GP2.wav
In car, same combo but I dont remember how fast.
http://home.earthlink.net/~wtomfoster/Gp7.wav

With a 280XFI cam, from the rear of the car about 15' away. Slightly quieter muffler than before and little bit different exhaust configuration.
http://home.earthlink.net/~chris.foster/GPrev1.wav
Same combo, at the track with the tank, Palmdale (~2710 feet+bad DA)
http://home.earthlink.net/~leftcoast_guy/GP4-21-07.mpg

Either of those cams I've used (similar to Comp 503, actually SLP 51010 224/232 112LSA and Comp 280 XFI, 230/236 +/-, 113LSA) are going to require tuning. They will run off a stock chip, but your rings wont like it after they're fuel washed for a few thousand miles.

 

All right. I'm kind of likeing the sound of the XFI280. But how good is that going to work in a stock TPI motor? I don't want to lose the driveability of the car. This car is going to be 90% street and 10% track. I'm affraid it will lose all the bottom end. Adam :-)

Also. What else do you have done to that car. It sounds mean. Have you ran it at the track yet?

And thanks again guys for all the help!!!

 

The last link is a vid of the car at the track. Its heavier than a thirdgen, doesnt hook up at all although its improving (think I have a lack of low end? I sure dont), and the air was terrible aside of elevation so if I were to correct the ET for both (and I despise "correcting" ET's) it would have been a 12.7 +/- on that pass in 'ideal' conditions.

As far as a 'stock' TPI, dont know. I have aluminum heads (AFR190's), 10:1 compression (so that would be close to a stock iron headed car), ported Edelbrock base, STOCK TPI runners (yes, seriously), and ported plenum... and 58mm TB though I suspect that did little if anything to the power curve. 1 5/8" headers, and basically a 3" catback exhaust.

Its funny you're now mentioning driveability because neither of those cams you originally posted is going to fare any better than the XFI280, in fact they'll be much worse. I'd honestly say forget the notion of losing low end power, too many people get overly concerned with that. SOTP I've never run into that, on any car I've modded aside of a 4 banger that was OE a low speed truck engine to a borderline race only engine and even then it felt ok. If you were to lose 10-20 hp at 2000RPM would you feel it? Doubtful. Will it work with a TPI? Well... yes but there's a lot left to gain. A TPI and the ECM prefer a wide LSA (114+) and not a lot of duration, like less than 220 is a TPI friendly cam. Beyond that its going to require tuning to get it back to the driveability of an otherwise stock car and even then, depending on the cam, its going to be different. Only you can really decide whats driveable and whats not, I think this cam is ok but it does shake and its a little tempermental at times especially when cold. But there's no lack of power whatsoever. To get a choppy kind of idle, driveability generally goes out the window. Either go with a tight LSA (like that 107 of the "Thumpr" cam) or a lot of duration (224+), or both. I ran a 204/214 110LSA cam that didnt make much more power than stock but it had a little bit of bite to the idle although not much. It needed tuned though, the stock chip just wasnt quite right and thats the 110LSA shining through. I did drive it for years on various off the shelf chips with no ill effects though so that should give you an idea of what you can get away with.

 

Well do you think I can get a better tune out of the OBD2 setup then the TPI setup. I did a quick serch on LS1tech and there's a few of them running 106 LSA cams. Also, every time I put one of those cams on the desktop dyno. It allways has above 400tq at 2000rpm(thats the lowest it shows). So lowend dosen't seem to be a problem. I also have 18x10's with 285/35/18 on them. So I sould hook up. Thanks again! Adam :-)

 

Maybe, but I havent had any experience with that ECM at all so I'm in the dark. I've read about how much better peoples cars run with that ECM though so... could work.

 

i never heard of anyone integrating TPI motors with LS1 OBDII setups. sounds promising but i'm sure you can tune the TPI style computer to handle anything, it just takes time and knowledge

 

https://www.thirdgen.org/forums/tpi/...-opinions.html There's few people running it. My friend is doing it on his 89 IROC. They thing I really like is that you don't have to burn a chip everytime you want to change some thing. So it would be easier for me to learn how to tune on it. Adam :-)

 

Its #10 on the list of top viewed TPI posts and stuck just above here. I just wish it would control the TCC itself but you cant have everything.

I guess that just tells me that post is still flying below radar. I dont know if thats good or bad...

 

You can't just look at the lsa, it is misleading.

I'm using a 107lsa in a 383 miniram'd GTA. 10.5:1 comp 230 dur .600 lift. The cam before it was a 242-254 .555 .585 lift 110lsa and it had way more overlap than the current cam. The 242-254 cam was tuneable and driveable also, but vacuum was an issue for me with the power brakes, even with a vacuum canister. I didn't have enough compression for that cam, it wanted at least 11.5:1.

I've had the '165 maf ecm on it before the current '730 sd ecm and both drove and ran fine. The more radical the cam, the more time you have to spend on tuning it.

If you send off for a mail order chip, plan on spending some money on postage sending it back and forth with data log info to get it right. I used to have an Ed Wright chip, and gave up and started burning my own after mailing the memcal back to him after the 6th time.

$.02

 

i havent been browsing the TPI board all that much lately. i just clicked new posts and this thread came up lol. I'm gonna go through that thread now.

 

Set aside a few hours then, its 10 pages long and climbing.

 

lol yes its long but i did a quick browse and still have more to go. looks cool but not sure its something i'd do

 

Im just wondering, but would the cam below that I just listed, be a decent cam or an overkill for a LB9 305 or L98 350. thank you.

---Comp Cam Magnum 270H-
Biggest cam with stock converter. Use lower gears. Mild rough idle.

RPM range 1800 to 5800
Advertised duration 270 intake/270 exhaust
Duration at .050 224 intake/224 exhaust
Lift .470 in. intake /.470 in. exhaust
Lobe separation 110°

Link is below if you want to check it out.
http://www.dougherbert.com/magnum270...d477c5bcf0cb18

 

thats just a hydraulic cam aint it? you'd need a roller cam which would put you about the CC305 or 503 cam with that duration range, unless you change out to flat tappet cam. i think it be great for a 350 and be a pretty hot cam for a 305. would definately want a higher rpm breathing intake

 

yeah its a hydraulic cam, and also, I have that cam but its installed yet, and I'm not sure If my Edelbrock Hi Flo Intake/ Runners would help as far as having a higher rpm breathing intake compared to the stock TPI

also, would you expect a decent gain from this cam, either for a LB9 or L98 compared to stock cam

 

yeah it probly would make for a decent gain. those hiflo runners/base could be ported out or siamesed abit to gain more rpms or flow, but it should work fine.