Folks,

What is the likelihood of success with this?

- 383 Stroker, 200cc irons, 64cc /w/ flat-top, 10.5:1
- Hogged siamesed TPI /w/ 24# SVO, headers
- Cam: 230I/230E@.050, .560I/.560E
- 110sep, 4deg adv, hydraulic roller

I guess with 110 lobe separation and 230 duration, it might be kinda tough to get good street manners with MAP. Should the 110 help reduce detonation on pump gas / 10.5:1?

Any helpful comments are appreciated. I'm thinking of trying this cam out and falling back to something a little more 'friendly' if it doesn't work out.

Primarily, I'm interested in how 'tunable' it will be. I guess vacuum / brakes will be a concern as well, also low-RPM torque (have 2200 stall to help).

Many thanks,
-Craig

 

What is the likelihood of success with this?

- 383 Stroker, 200cc irons, 64cc /w/ flat-top, 10.5:1
- Hogged siamesed TPI /w/ 24# SVO, headers
- Cam: 230I/230E@.050, .560I/.560E
- 110sep, 4deg adv, hydraulic roller

Turn off closed loop and tune with a wide band. Turn off all extra modules and get the curves straight. Then turn stuff on one at a time and deal with the problems. It will probably be tedious and require you to address every module you want to run.

I guess with 110 lobe separation and 230 duration, it might be kinda tough to get good street manners with MAP.
Should the 110 help reduce detonation on pump gas / 10.5:1?

110 separation is fine it just requires more work. Forget closed loop BLM following for tuning and go straight for the wide band. 110 causes higher pressures due to charge trapping and makes the engine more likely to detonate near peak torque.

HTH

John

 

this smells a lot like my motor, although I am running a SR. I have about 40 45 KPA @ idle & then @ cruise it comes down to about 25 or 30 or so. this makes the tune a bit hard because it has a bit of a hump in it, instead of a nice sweeping transition.

I was using the bin that Zimmer made for me as my baseline, but it was hozed & figured I would just start over with a stock base. that seems to be working out fine. it is quite a bit of work though, & I dont have the time for it.

I have been using VE Master & that has sped it up a bit. I think that I have a cold enrichment issue that I have to back out, & then I think that the tuning will go OK. I dont have a WB, so I figure I am going to tune WOT the "old fasioned" way, with plug cuts & a time slips.

I am using a vac pump for my brakes, becuase I want them there 100% of the time, repeatedly. but I would probably be OK w/o it

BW

 

Craig, that looks like a 8-450-8, maybe? On page 229 of Comp Cams catalog it shows the 230° @.050 to be 286° Seat-to-Seat so it's at least the same or very close. The lift is .560 I/E also.

I ran that cam through 194000+ Iterations with DD2000 for both max torque and max horsepower then adjusted the LCA to 112. It shows gains in both areas. I went from 10° on both sides of the intake and exhaust to see what it came up with. I'll attach it.

I may custom order it or may just go with a 8-432-8 instead with 1.6RR for the winter. That 8-306-8 looks good too!

I'm in the same boat as you in wondering if I cam tune it ok, except this is my daily driver. We have some differences in our setup also. I'm running a Stealth Ram intake and aluminum heads.

I know I didn't answer your question but. . ., let us know how it turns out.

SBC 383 w/TFS 23° aluminum heads, full roller, 11:1 SRP's.
730SD w/30# injectors, 58mm BBK, Holley Stealth Ram
700r4, 3.73 gears w/BFG drag radials. 4040# Pickup truck.
8.74/78.95mph (1/8 of course) w/1.97 60' w/stock suspension

Oh, and CMoates 16 bin switcher! (Hows the remote switch with the display coming along?)

 

Not sure which ecm your running (730?) but with my 747 I set the Rich, Lean, and Median R/L (O2 sensor voltage) lower in the 16 g/s area in all 3 of these tables. eg: I moved the O2 toggle point from like 525mv to like 400mv. My cam isn't as big as yours, but this caused much more stable low rpms <1500. This is because big cams push unburnt air right out the exhaust at idle, as I'm sure everyone knew. Now this unburnt air doesn't make the ecm think I'm going lean, so intern it doesn't dump fuel in to correct. My motor runs great in C/L at idle. I not sure if the 730 even uses these talbes, but they increased my motors drivability more than any other tuning of late.

 

Hi Craig,

I dont feel you are going with that radiacal of a setup. I run a 248/248 solid roller in my 383.
My idle is 66kpa at 925. I have a stick car. I think I could idle that down even more if I wanted maybe 900 or 875 for a auto setup.

I am running a 112las, +4deg. So the 110 you are thinking will give a tad more chop...But in all I see no programming issues.
Dennis

 

i will speak. LOL. ok first most large cams engines appear to have less vacum. this is sort of a half truth. what your dealing with is reversion. the best fix i have seen so far is grabbing a vacum canister like the ones used on ford vehicles with HO 302's and plumping it inline to the map sensor. the downside to this is that there is a small delay in map output but the benifit is that the vacum at idle becomes much more stable. this will slow down the pulsation by providing a resivor all bit it a small one like a 60 gallon compresor tank. the compressor head will always be able to supply the tools with air. but with out that compressive layer of boundry air it will pulsate. the same hold true for vacum, the canister will provide a buffer to help smooth out the vacum to a more median average. i think youll be fine tunnign that cam however i would think a wider LDA of 112 would provide more street manners. i dont think you will have problems with detonation as long as you move up the thresehold for the highway spark and fuel modes. or set those zones to zero.
criag send me mail man. talk at you later.

 

Or, use a 4' long 1/4" vacuum line to the glove box like I did because I was too lazy to extend the wiring to the MAP sensor.

I idle at about 45 KPa which is about 13.9" with the 8-412-8. Nice steady lope to it though. I've always wondered how much delay it has caused with the MAP sensor but it tunes just fine and seems OK. Response seem quick with the scanning software too.

I'm going to order a custom gring Comp Cam soon. We waited 6 weeks for one a couple of months ago but the guy said they are a little bit caught up now.

 

yeah the same idea. just provide some volume to soak up the reversion pulses. then it all smooths out.

 

Craig how are you comming w/that cam? I just placed that same one in and am waiting for heads to get back from shop. getting some short side work done.

 

I'm still dragging, nothing yet...

 

In WinBin and Astros definition file, are these tables available? what are the names? And any advice on adjusting them?
I like the idea of adjusting the toggle point down a bit. I am using a 747 in an old motorhome with a 330HP crate. seems to have lots of cam and somewhat lower vacuum.

 

Why not dare to be different?.

Try Aplha-N.

 

The times I've tried that with much smaller reserves, the delays made the car about undrivible. The MAP based AE goes straight down the tubes with too much reservior.

It was much better to actually get the calibration right.

The reason GM uses a small cross section hose is for a specific reason. If someones using a P4 ecm it would be much better to change the filtering in the code if they couldn't tame the engine with tuning.

Dampening for pnematics is done about the same way as with hydralics, looking a shock will fill folks in on how to dampen a signal. But, again that screws up the AE stuff.

 

I don't suppose you would care to throw me a bone?

 

yeah i negated to meition the fact that i was teeing in. much to my chagrin. bascially i place the vacum hose into the map with a t then run a resivor off the t and the engine vac off the other side.

so engine vac line T map

vacum resivor.

yeah grumpy i had the same problem. cant use a huge vacum reisvor.

 

WHo needs a vac resivor when you have a large volume plenum intake

 

Chop top,

Just play around with the tables to find what works best for you, I found decreasing the "window" (the voltage value from the rich point to the lean point) helped at low flow. I just decreased the values until the "pig rich" idle was gone. Find out if your cam make stoich afr, eg: my cam (222/226) doens't hit stioch below about 1100 rpm, therfore I want a lower toggle voltage below that rpm to compensate.