your opinion on a "stealthy" cam. Will a XFI lobe 224/230 .609/.605 118 +4 peak before 6500rpm on a 346ci? It should idle about the same as my stealthII (224/220 .581/.581 116 +0), being it only has 1 less degree of overlap, should have better dcr with 2*earlier ABDC IVCE and better PTV clearance with 2* earlier IVOE, right? Thanks, Chris

 

If you already have the stealthII in the car, I don't see how it would be worth it to change to the XFI cam. These sound loke better turbo cams than N/A cams. If you decide to put the XFI in on a N/A car, I would put it at 114° ICL.

 

I spun a bearing and am building a new short block...I liked the results of 427Z's ls2 w/ a 226/230 117 and have been lookin at speedinc's sc3 grind (XER 226/234 .598/.599 117), but heard the XFI lobes are better than XER and easier on valvesprings

 

dont think you get an XFI lobe with that high of a duration.

IMO keep you lift under .600

XFI lobes would be more like a 202 with .585, 210 with .595 or 214 on .600.

I think one really needs to ask, "what do I want my car to do? Daily driver, Weekend cruzer, Strip car or ??"

and does the car have to pass emissions?

and do I like immediate SOTP acceleration?

Smaller cams will accommodate the last two. May not be the dyno kings, but will have SOTP acceleration.


Texas Speed has some very good cam options:
http://texas-speed.com/shop/category...MID=4&catid=44

 

A 118 lsa is going to idle well but you're giving up a lot of low end power.

 

Wrong.



Go with the TSP 228R cam on a 114LSA. You can barely hear any lope, and with a 900RPM idle it will sound nearly stock. Drives great and makes decent power. 118LSA is overkill.....I don't even think the stock cams are ground on that high of an LSA.

I'm running a 231/235 .617/.620 112+4lsa and it peaks at about 6400.

 

118 or 117 is not really worth the time, not overkill but under ustilzed of the other valve events

a 114 lsa MAX and I agree the TSP 228R on 114+2 would be a very good choice a 112+2 would be a better choice.

Everyone likes a little lope

 

What are the characteristics of a turbo or F/I cam - vs N/A?

not to hijack the thread - but I am looking for a good cam
daily driver hardly ever to the drag strip - have done a few autoX events in the past - mainly spirited driving on street.
402 forged - just found some AFR 225 72 cc heads with upgraded springs good for 650 - waiting for them now.

Thank you

 

I know the wide lsa will not make the peak torque as a narrower lsa, but I believe it will make more avg power...I also want the wide lsa for the "stealthy" idle and it's easier to tune...shouldn't it have better low end since it doesn't dilute the intake charge w/ less overlap? but not really worried about low end since I have 4.10 gears for sotp. My heads are ported and flow .600"+, I was under the impression the XFI lobes are better than XER lobes. I believe the LS7 cam is ground on an 119.5* lsa and the gt11 is on a 118.5*

 

XFI lodes have better air flow at .200 to .500 lift and are easier on the valves seats, but do not have much lift

As we mentioned before XFI would be fine, but dont expect huge lift. Many times lode designs are combined for optimal use.

And also this is were talking to an engine builder to work with the best combination of your parts and what you want your car to do.

The LS7 cam is for emissions and good power. Remember the current LS7 cam was the THIRD cam Chevy used to get the HP down to 505. the first two cams were bigger.

you can still run a 117 - 118 lsa, Cams like that are for emissions or turbo and FI use


as Kevin mentioned above those higher lsas will suffer for low end tq. all 4.10s will do is make you shift more, not really faster

Lingenfelter GT2-3 207/220 573/580 119
LS1-GT11 215 / 231 .631" / .644" 118 1.7 ratio

215 .631" may be an LSK lobe
231 .644: IS an LSK lobe

This cam may need to have the springs checked each year, Not easy on springs. with that much lift and duration.


Here are some LS7 cams from GM

LS7 stock 211/230 591/591 120
230/231 593/588 120
227/239 551/551 108
233/276 595/595 107

 

I found a cam designed by patrickg I think on the other forum that's a XFI224/230 .609/.604 on 117...the XFI lobes are higher than the XER, but not as bad as the LSK, take a look at texas speed's custom cam page...never heard of that 230/231 120 ls7 cam it'd be interesting to see it's power curve...my sig may be decieving thinking I only drag race, but I also auto-x and hpde...I have more than enough lowend on the street and am looking for a smooth powerband that does it all

 

Yes Patrick does some great cam specs. The XFI224/230 .609/.604 on 117.. is something close to what I am looking at.

But to me that 117 push the power band too high. drop that lsa down to a 112 and your power will come on say 200 rpms sooner


To give you an idea

I have a semi stock LS6, polished but not really ported 243 heads, New 921 springs each winter, TPIS Lts, random tech high flow cats and X-pipe then straight pipes, no muffler
my own CAI, 3qt accusump and oil cooler

My cam is small 224/224 581/581 on 112 I run 402 rwhp and 407 rwtq. But at 3000 rpms where most engines are just under 300 lb ft of torque I am at 380 and hit 400 lb ft at 3300 right up to 5000. almost flat tq curve. Yes ppl think I have a bigger cam then I do

What this does for me is I have more get and go out of corners from 40-50 mph to 120-122 mph then most LS7s. Over 125 mph I am toasted. BUT how ofter is one above 125 mph on most road courses? Road courses are high speed corners first and foremost, then high speed straights.

So overall my lap times are about the same as LS7 motorer cars. well I am also a bit crazy in brake zones, as I brake very very hard and very late, so I tend to catch those cars that did pass me on the high speed straights, as I go 100 feet deeper into brake zones.

 

hahaha Thats how races are one

 

I understand you're interest in mid range power for corner exits and have no doubt if the cam was ground on a 112 it'd make more torque at 3k rpm, but I believe the 118+4 would bring the powerband down like a 114 and make a better avg from say 4500-6800rpm where the engine spends it time when running down the 1320 as my goal on the new setup is to have a stealth n/a 10sec 346ci

 

You still have to get off the line. That is where a comprise comes in.

Over on LS1 tech there are several threads on 10 sec LS1s. You might be suppressed at the set ups. 10 sec club http://ls1tech.com/forums/forumdisplay.php?f=88


Good Luck