breynolds

iTrader: (1)

Over the winter, I built the motor to replace the stock LB9 that was in my car while the actual car was off getting a cage fabricated. I used the CamQuest6 program that Comp offers.

http://www.compcams.com/downloads/register.asp

It led me to pick up this:

http://www.summitracing.com/parts/CCA-08-468-8/

Fast forward to me getting the car back, put the engine in, and off to Dynosports in Lincoln, NE to get tuned. Long story short, my tuner said that the cam wasn't giving enough vacuum for the MAP sensor to properly read in the lower throttle values. Basically, at 15% throttle, the MAP would show max value. Either 0 or all the way pretty much.

Full throttle, the car is an animal. Lots of top end. My problem is lack of driveability. It has the chug of death if you're trying to just drive it nice and easy from a stop or stay at a constant RPM under 4k. My torque has also suffered quite a bit I found out after taking it to the track this past weekend.

Posting this so maybe someone on her can recommend something better or at least lead me to a phone number to someone that knows.

Combo:
Block: 87+ roller
Disp: 355cu
Comp: 11.1
Heads: Dart Pro1 Platinum 200cc 2.02/1.65 valves
Rockers: 1.6 ratio Pro Magnum
Lifters: Stock style Hyd Roller
Intake: HSR with 58mm TB
Fuel: E85
Exhaust: Hedman Elite series LTs. Muffler, no CAT

The car may see a 150 shot on it now and then, but kinda rare. I built it to do some road racing with, but primarily be a street car.

formula_novice

iTrader: (1)

That cam is way too big if you expect to get good drive ability in a 355. I'm not surprised you have idle issues. If you want good drive ability and idle, the XFI-268 I use is a good choice. If you want something a little more, the largest I would go is the XFI-280.

Just my 2 cents. Hope this helps!

ninetyone

iTrader: (2)

Wow, huge cam for fuel injection. I wouldn't go past a 218/224 @.50 or better yet, I would try something like the L98 supercam 220/220 @50. Just my opinion

ninetyone

iTrader: (2)

what gears do you have outback?

F-BIRD'88

That cam will need a 3600 to 4000 stall converter.

That cam will need full timing at idle 36deg +.
You need a way to force the EFI computer to use set fueling values up to about 3000 rpm,
Based solely on throttle position and rpm. and ignore the MAP and MAS sensor.

Guest

I'd try a 224/230 113 573/568

Orr89RocZ

iTrader: (20)

x2. I'd go even higher on stall. We run a 3600 on a 360" motor with 280xfi cam and its abit lazy still. It could use 4000 and that cam is much smaller than the 292xfi.

Set open loop fueling mode on the ecm, tune from there. You wont have much range on map, but it shouldnt be maxing out the MAP sensor at part throttle. It should still develop some vacuum at cruise.

Higher idle timing will help. Idle at 1000-1100 rpm will help. It will take alot of tuning time to get that thing to work somewhat properly but its doable to get good driveability with that cam and that compression. Just expect higher idle speed and alot of work to the fuel tables in open loop mode.

But I'd honestly step down to the 280 xfi if you want a big cam. that cam is a nice cam that still gives driveability but will rev out to 6500+ provided the springs in the heads can handle it. It needs a strong double spring with 150lbs on the seat, closer to 380-400 open pressures.

breynolds

iTrader: (1)

This is a 5spd car BTW.

I really need to get the power down in the RPM range and quite frankly, I'm not convinced this cam with a HSR is capable of that. It was just a dog out the gate. Not enough of a dog to not grenade my diff evidently, but I literally had no use in putting on my ET Streets. Just left the C5 Wheels and tires on. I'll admit the track was pretty sticky, but damn. I ran better 60' times with the stock LB9.

breynolds

iTrader: (1)

I ran the Camquest 6 program again and was looking at some different options. One of them that was suggested was the 276 grind. Another question, is the NX grinds any different than the XFI grinds of the same number...meaning necessary if running the juice.

Orr89RocZ

iTrader: (20)

That program is junk. I wouldnt use it. It just helps you get one of the cams on the catalog main pages. You can do that just buy reading the catalog.

Nitrous grinds have abit different lobe design than the xfi lobes. If you want a car with good overall power and good top end that holds on for few rpms after peak for road racing, then I think your looking at a custom grind. I'd say 8-10 deg duration split would help to get exhaust out of the cylinder at higher rpms but a relatively short intake to keep powerband down in the lower mid rpm ranges. Something like a 220/230 or 224/230 or 224/236 even. Tight LSA around 108-110 lsa or so. That would kick butt. Something like magnum lobes 3119/3112. Just a guess. Anything in that region would work.

An XFI cam using the custom setup 224/230 would be much better for your needs than what you have now, i'd just tighten the LSA up 108-109 or so

The 292xfi is duration wise about what I will be running in my 401...except I got a ton more lift and abit more duration. Its good 400" motor cam for 6500 rpms. NO idea why camquest choose that for a 355

ninetyone

iTrader: (2)

what gear ratio are you running? Where is your timing and fuel pressure at?

breynolds

iTrader: (1)

Thanks for the input. Would calling Comp and telling them exactly what i have and what I intend to do with it do any good? I've heard horror stories about uneducated people trying to give tech advice. I just don't want to spend money on 4 different cams before I find one that's decent.

breynolds

iTrader: (1)

Probably part of my issue. I'm in the process of swapping rear ends and eventually will wind up with most likely a 4.11 ratio rear. Timing and fuel pressure are set at stock initial. I know that getting the FPR to stay constant was a pita from what my tuner said.

Orr89RocZ

iTrader: (20)

They likely have guys there that will do what you want done, but i've also heard some stories here and there. If they are doing a custom grind then it may have a better chance at working but asking them for a recommendation of one of their shelf cams, then its hit or miss sometimes.

You can try Bullet cams, Mike Jones cams, Cammotion, or Bret Bauer at Bauer Racing. They know cams well and can figure something out. I used mike and bret on my motors in the past and it did everything I wanted to do and then some. Bret selects cam lobe design and has comp cams grind it. Jones, bullet, and cammotion I think have their own lobes. My 383 HSR cam was done by Bret and it made good overall power with a peak at 6200 rpm and held that to 6600 rpm+. Very broad powerband with strong low end. Something similar to that cam but abit smaller for the smaller cubes would be awesome. Bret will not tell you the specs off hand, you place the order and get your cam and cam card in the mail later on. He is pretty good with cams although you may find some negative posts about him throughout the interweb Jones did the cam in my twin turbo motor. Ran well. Jones did alot of cams on this board too and made good to great power. Reasonably priced too, not much more than a shelf cam.

Guest

I'd rather believe Orr89RocZ than 98% of the people at Comp.
But part of your current problem is the overlap. Better to lose a bit of midrange torque with a wider LSA to be safe, and with it you get a safer DCR.
The tight LSA gives you a torque "curve" like Mount Fuji. A wider LSA makes your "curve" more like the Colorado plateau.

ninetyone

iTrader: (2)

always better off with too little cam than too big.

breynolds

iTrader: (1)

Sent Comp an email with my specs and combo and asked their opinion. This is what they recommended:
http://www.summitracing.com/parts/CCA-08-467-8/

I think that is a little too much cam. I would look at part number. 08-467-8. Duration steps down to 230/236 lift is still strong with .576/.570 with a 113 LSA. This will make more vacuum, but if you still need more, you may have to look into a vacuum pump.

formula_novice

iTrader: (1)

Right, that's the XFI-280 we were talking about. As mentioned, make sure you get a good set of springs to go with it.