Im looking for a little help picking out a new cam to compliment my intake/head combo. Looking to pick up 20-30 hp, maybe more. Im currently running the cam in my sig-- comp 276hr14 220/230 @.050 .540/.540 with 1.6 rockers. I've heard negative things about the 114 LSA with this cam but im not sure what would be better. I have my eye on the comp 280XFIhr13 230/236 .576/.570 with 1.6's. but its 113 LSA isnt much diiferent from what i have. Any ideas on what a better cam would be, maybe from a lesser known company or something i am overlooking? Engine specs in sig. the most lift the valvesprings can handle is .600 and i dont want to spin the motor past 6000 with the stock rods/original bearings. Also it needs to be compatable with my 1.6 rockers.

I like the lift and duration of the XFI cam but would tighten the LSA to 110-111. Do not go with more duration or it will push your peak HP too high in the rpm range. I ran a XE 230/236 112 LSA in my 383 and it peaked at 6500 rpm. Being that it's best to shift a few hundred rpm after peak, it would place my shift point around 6800. If you tighten up the LSA, it will bring your peak in sooner and make the motor rev much quicker.

Last year I went to a 110 lsa installed at 107 and the motor responded extremely well.

I am almost running the same setup as you (not installed yet). Same cam also, but mines 110LSA. I picked it because I also didn't want to string my engine over 6000rpm. I hope I can run the times you did! Did you have the heads milled or run thinner head gaskets to keep the compression up? That is assuming it went on a stock engine.

By the looks of that cam you posted up, you're going to have the string the engine a little past 6k.

The heads are 65cc combustion chamber. I figured that would put me at around 10.0 to 10.5:1 comp ratio. I think the stock heads are 75cc? I'm just really struggling to find a cam with high lift numbers and medium duration on the LSA that i want. I guess i could call Comp and have them grind me one? 225/235 @ .050 .575/.575 on a 110 LSA? lol i just dont want to sound like an idiot when i call them or wind up with a cam im not happy with.

Call Comp, Erson, Schneider, Lunati, Isky...ad nauseum. This is their JOB, this is our HOBBY. I imagine they could put the xfi280 roller profiles on a tighter LSA if they felt that would make you happiest. They hardly ever make a new profile for someone, they use their existing profile bank on differing LSAs. Call a couple companies and get the lift and dur @.050 and the LSA and come back here with some numbers, That way you have narrowed the choices down significantly. Math dopesn't lie; I imagine the 3 designers you pick (say Comp, Isky and Howards), will have extremely similar numbers; then just find someone with desktop dyno to plug in the numbers and perhaps the hp wopnt be spot on with what you get, but the tendencies on the graphs will be pretty realistic for comparison purposes.


Another option is to get Tony Mamo over at AFR to reccomend a cam that maximizes your heads. Either way, Id really use the free tech advice youve already paid for to narrow the field, then poll us to help in a final decision
BTW a 'custom' grind isnt much more than a shelf grind. I think our Crane cam in the 2.3 ford was $50 more

64cc for the L98 iron heads, 58cc (+/-) for the L98 aluminum heads.

Do 1990's have dish pistons? I think I read the 1990-1992 got flat tops.


I would call around as suggested and see what information you can gather from them.

Wow i'm surprised it went that high at peak. I was quoted that I'd need a 240/243 on a 108 to reach that rpm on my 383 HSR motor. My 230/245 ona 109 only hit 6250 peak but held that well to redline which was 6800 on that motor


Miniram/LT1 intakes seem to like tighter LSA's and minimal intake/exhaust duration split with good heads. Its just how the grinds usually come out from what I'm seeing. For that motor and not going over 6000 rpm too much, you must not go over 224-226 duration on the intake in my opinion. Anything bigger will likely be best shifted at 6500 or more and peak above 6000-6200.

Advanced induction has a nice 226/234 grind on a 110 lsa. Something along those lines would work great.

You could call Lloyd Elliott who does custom LT1 heads/cam packages that do make some power, and he could get a nice grind for your motor. Bullet cams does the grinds for him.

Mike Jones from Jones Cams is who I went with for my new cam for the turbo motor. He does good work. 1989GTAtransam on here has a grind from him that did nice work on a 355 tpi car.

Either of the big name custom cam grinders will set you up to take full advantage with your setup. Definately would like to see 224-226 duration on the intake with a 4 degree split for the exhaust duration and mid high 500's lift and lsa will probly end up being in the 109-111 range.

My Lloyd Elliot cam came from Ultradyne.

I checked out advanced induction and that 226/234 cam is exactly what i wanted. thanks for the help

Orr - 6500 was much higher than I anticipated. I believe it's the MiniRAm that pushed it that high. We tuned the motor on a Dynojet Chassis dyno.

After running tighter lsa's, I'll never go back to anything above 110. I would rather run less duration, more lift and keep the lobes tight. Basically "area under the curve" as they say.

Called Advanced Induction tuesday and talked with them for a while. Very nice, helpful guys. They decided to cook me up a custom cam, and I think they did a perfect job. They emailed me the specs this morning and hopefully i can have it in next saturday




I figure this will have a STRONG torque curve between 3000 and 3500 and HP should peak around 5800 to 6000.

I am in the process of installing a converted LT1 intake on my car, and my cam is going to be similar with a bit less lift...the Comp XE 432-8. 230/236 duration, 110 LSA, .544/.554 lift with my 1.6s. One of the fears I have is peaking too high as well. Your specs seem so smiliar I'd like to know where yours actually does peak assuming your build finishes before mine (i'm shooting for june 1 or so)

That cam will probably peak around 6200, maybe a little lower with your 180cc heads. You could install it 2 to 4 degrees advanced to bring the power band down a little bit. Not sure but you may need to check your piston to valve clearance with the cam advanced.

I should have mine done next saturday, and i'll be at the track the following weekend.

Wow, wonder what they use for advertised duration point measurement. 225 degree lobe at .050 on a 258 advertised is a FAST ramp cam. You'll want to be sure you have decent valve springs with good pressure to control that beast.

Should rip tho providing it dont float the valves, thats a pretty aggressive lobe from those specs

I noticed that too. I haven't asked them where they get their advertised numbers from. If its .005 like most companies it is AGGRESSIVE. However if its .020 then its no problem. Cam companies like to make their advertised number as big as possible just to sound better then the next guy. These guys know what springs I have and I'm sure there won't be a problem.

Haha, I can see it now...."yeah, i switched from a 276 cam to a 258 cam and made 30 more horsepower"

like orr said, i am kinda worries about the ramp rates on the xfi line, i am going to be putting together a 9.3:1 afr headed 355 with the xfi 292...

the afr springs are rated to 600" lift but that dosent mean they can handle a fast ramp rate up to the 600" lift, i think i will be ok if i get their hydra rev kit...

go big or go home i guess..

The hydra rev might be the key.

Hydraulic roller cams are nice until you start thinking of building a high reving race motor. Then it just costs a fortune to keep it from exploding.

-- Joe

well whats funny is that afr's springs they put in the eliminator heads are nearly the exact same specs as comp reccomends for the xfi 292 cam, i can look at my cam card for the part number but i remember researching them and it was almost the exact thing it called for....

as for me, the valvesprings will be the only problematic thing as far as rpm goes, i have a 4340 crank and h beams and will have kb forged pistons.... that with a t56 and 4.56 ford 9" should flat out move in the 1/8....

my buddie bluegrassz runs the xe282 cam with a 112* lsa... if im not mistaken it's near the xfi 280 specs, as far as duration and lsa is concerned.... heres a link to a video of it.

http://vids.myspace.com/index.cfm?fu...deoID=29558936

http://vids.myspace.com/index.cfm?fu...deoID=26747433

it's not too wild, and fits his afr 190's perfect..... when i sold everything to him he took those heads to a shop and the guy changed a few valve angles i believe due to turbulance and got some pretty good flow results..... hit bluegrassz up he can tell ya more about it....

If you are going to run AFR heads, get their upgrade spring the 8019. I ran that spring shimmed alittle bit for 170lbs on the seat spring pressure and i took my car to 7K rpm
Peak power was at 6300 tho but didnt fall off much past 6500. I shifted at 6800 alot and didnt see much difference in ET so i dont think i was floating the valves.

Any steep lobe cam or hydraulic roller wanting to rev up over 6200 rpm, i'd recommend over 150lbs on the seat. 160-170 is better for the really aggressive stuff. LS7 lifters can handle those pressures

Put the cam in last saturday and spent most of the week tuning it. This cam seemed a bit tougher to get tuned right compared to the old one. I had to lean it out alot in the lower end and i ramped the timing curve to come in sooner. I raised the timing 3 degrees all over in the lower end and 1 degree from 5000 up. Throttle response is GREAT and the engine is much snappier then before. Went to the track saturday. Weather was close to 90 and over 50% humidity



compared to 1/8th mile two weeks ago with old cam, same weather



compared to last october 40 degrees, no humidity



My 1/8th mph is up 2 but my 1/4 is down 2. I think its going lean up top, i never added any fuel from 4500 and up. All this thru the factory firebird air snorkel,ORIGINAL FUEL PUMP, 3445lbs

My car has always been 3 to 4 tenths faster in really good air compared to the summertime. 11.60's to 11.70's in the fall would be nice.

Looks good so far. Definately play with the fueling on the top end. I"m surprised its losing 2mph so far when it is up 2 in the 1/8. Also looks like your launching much better. 1.6 60's compared to 1.7 before?

Air and temp. have alot to do with my 60'. Im glad I took it the week before I put the cam in for a true comparison. You can see when the air was better it was doing 1.61-1.62. It went mid 1.50's with the tpi. I made up some new tunes yesterday and cant wait to try them out friday.

What suspension piece do you think dropped your 60 ft the most?

Just wondering if those numbers included any kind of power adder like nitrous? If that is motor only, how much weight reduction have you done to the car?

I'm getting ready to put a miniram on my 88 GTA running a very similar setup for engine and heads and I'm curious if anything else has been done to your car to get the times down into the low 12's like this.

I'm not really sure. I put the torque arm, lca's and lca relocation brakets on back when i was running 13's. I got the k-member, control arms and coil overs thinking i would shave 50 pounds or so, butI cheaped out and got mild steel instead of chromoly and everything wieghs the same as stock. The feeling on the launch is definitely nicer with the coilovers (300 pound QA1's). Much more consistent lights and 60' and it seems to start moving forward before it rotates up. Tires are about 6 to 8 inches off the ground on the 1.60's. Everything just works good together.


Beater79ta----its a full weight GTA. still has power seats and full interior. 3445 with me in it. I've removed all the accessories off the motor and it just has a low mount alternator kit and electric wp. Lol the cruise control still works in the thing. And NO NITROUS!!!

Its just a bracket car that sees about 500 passes a year. I know it has at least 2500 passes on the stock shortblock I have boxes and boxes of timeslips floating around

Thanks. That gives me hope I can finally get my wife the speed she wants out of her 88 by upping the cam and adding the miniram intake to the AFR heads and forged internals the car already has.

Just to update, I made up a new tune with slightly less PE and I took fuel away below 2500 and added fuel above 4500. I raised the fuel pressure a few pounds too. Weather was HORRIBLE....hot and VERY humid. First pass was a 12.002 at 113.8 with a 1.586 60' (over cast but hot and humid). I bumped fuel pressure up 1 pound and the second pass was 12.006 at 114.1 with the same 60' (sun was out and even hotter). I bumped fuel pressure up 1 more pound and apparently it must have been good because the ring gear broke about 10 feet out and in the resulting lockup grenaded the trans. So now I get to thrash on it in time for the Pinks all out at MIR on the 20th.

With the extra fuel I got my mph back, which was what I wanted. Also I noticed on my datalog that my map reading is 95 kpa at wot, it used to be 101 so apparently my 52mm tb is just a little small.

Contrary to what the retards on corvette forum may think, I agree with you. If your MAP is down under WOT (with same baro conditions of course) your throttle body is now a restriction.

The opening on the miniram is huge and supports a 58MM just fine. In fact, when I sold the miniram I had a 58MM that I sold separately.


The only thing I'm wrenching on right now is my tractor, but I'm looking at second gen tonight. If it's a good candidate for a street/strip car I'll pick it up.


-- Joe

If I'd had the extra coin at the time I would have bought the tb from you too. Unfortunately the outragous price you charged for the mr made it impossible!! lol jk. good luck on the second gen and I can't believe you got rid of the vette.

Hah.

The vette was a $23,000 headache.

The 2nd gen I looked at tonight was rotted. 'minor rust' the ad said..

I don't want another thirdgen. It's either first or second for me.

Guess I'll keep looking.

-- Joe

Good to see your gaining the power back. Just keep playing with it once the rear and trans is fixed up. Should pick up for sure, once its tuned and has no air restrictions

GTA matt, you know your TB might not be the source of your restriction. You may want to fix up a better cold air intake, Im thinking your factory intake tubing may be causing a bigger restriction than your TB? Just a thought.

BTW hows the tranny and rear comming?

Fixed the trans and rear last month and ran in MIR's pinks all out on June 20th. Been racing all month and got it down to 11.94 @114 in the heat. I've been playing with timing alot. If I bump it up it et's faster but mph is down, if i bump it down et is slower and mph is up. Unfortunately the ring gear broke again last friday with about 40 or 50 passes on it with 1.58-1.60 60fts. Looking for a 9" right now.

BTW I was playing with the air snorkle on the car. with it on went a 12.019. ran open tb and went a 12.018 so i really dont think that is hurting me.

Impressive times. Smallish cam, low compression (9.3:1) yet 11s at 114mph.

I wonder what would happen if you angle milled those afrs to get the compression to around 10.5:1.

-- Joe

Well, when I got those heads my intention was to put them in a 383 with a big solid roller and 12-13:1 compression. Work dried up so I stuck them on the 350 until I could get the other motor built. I'm glad I did because I've learned a ton about tuning and cams over the past year. I still have the block here ready to go but no rotating assembly yet.

I have a block and rotating assembly (412) but no heads.

I'm strongly considering the RHS iron 220cc heads.

-- Joe

what are you shifting at?

who?

-- Joe

GTA Matt

My ultimate goal (not with this car) would be a 434 with a huge cam, afr 227's and 2 kits on a 275 tire. Just waiting for work to pick back up.

And I'm shifting at 6000, going through the traps at 6000 to 6100. feels like its still pulling hard too.

my peak hp is at 5700, and people have been telling me to shift at 6200. I am very weary of going more than 6000.

GTA MATT, have you tried shifting higher on that stock shortblock? Just curious as I would think 6200 or so would improve the times.

How are you doing the timing, I assume in the chip/bin correct? Did you bring in full timing by 3000 rpm or so?

Why so weary? Your motor should handle it fine and your power curve doesnt lie..its still going pretty strong to 6200 rpm

I don't know, we shall see if shifting at 6200 makes much of a difference, hopefully it does

I'm sure 6200 would do the trick too but with as many passes as I put on this thing I'm comfortable leaving it at 6000. I have the governor in the trans shifting on its own. I've tried doing it manually and for whatever reason it wont come out of first until I lift. Been like that through 4 rebuilds so I just left it alone. It turns out its way more consistent that way anyhow.

And the timing is all done through the chip. I just leave the base set at 6. I have full timing in by 3000 and I've tried to ramp it in sooner (kinda like a locked out distributer on a carbed motor) but it hits the tires VERY hard and either chatters them or breaks loose (or breaks the ring gear) I'm happy knowing that theres more left in it though.

One more problem I am having: It has a strange bog when shifting into third, shifts fine, rpms start climbing (go up maybe 2-300), then it lays over and the rpms slowly drop about 200 and then picks back up and really starts pulling. I checked plugs to see if it was going lean but they are perfect (still have stock fuel pump). It feels like it is the converter locking up so I set the lockup speed in low gear at 120 to see if it would go away. No change. Then I set the lockup speed low and to engage at wot to see if it would lockup at the shift. Again, no change. I would prefer for the converter to be locked up as it went into 3rd. Any ideas on how to do this? Looking at the increments on the timeslips it should be going about an 11.70. I've noticed racing other cars at the track that I rip them out of the hole, they catch me mid track, and I pull on them hard at the big end. All this occurs at the 2-3 shift.

same with me, and I have a newly rebuilt probuilt 700r4 with a new converter

Thats good to see... car is making loads of torque. Should beable to hook tho on a good tire, just need to tweak the suspension. Hows the track prep?


Sure does sound like converter locking up. My car always ran faster with converter open, i set mine to 130+mph. Its the TCC Unlock Prevention Threshold constant I believe. There are controls to lock it at part throttle but the threshold mph is what controls 3rd gear full throttle lockup. If it is indeed the converter locking up and its not responding to the threshold chip value, then try unplugging the TCC sensor connector to force open.

I'd be thrilled if my car came close to what your car runs Matt! My car is still shifts at the stock 5000 rpm. My cam makes peak power at like 5700, and I should be shifting at around 6100. It starts to yank real hard, then it shifts. Boooooo I'm waiting on a stall/governor because I'm just going to order a Pro-Built with a stall this winter.