Aaron91RS

iTrader: (2)

Who here has a aggressive cam. Like 275 duration and .550 lift on a 400 block. Or something a little less on a 350 or 305.
If so does it idle and have enough vacum. Do you run a custom chip? If so did it even start with the stock one?

chevyboy07 91

212-216 duration is a REAL pretty cam for a 305>>>>>(stock or modded)>>>>>>But use a chip.
224 and around there is also very nice and aggressive *enough* for a 350 No problems w/ any of my build-ups EVER.

chevyboy07 91

Ohhhh>>>>>and in a real aggressive 400>>>>234* duration is plenty IMO. Are those numbers @ advertised durations????? 275 is huge man

Grumpy

Used a 270 Comp Cam, with my 355, TBI (cross fire)(1227747), and ran easy 13s

Pablo

iTrader: (1)

214/224 .474/.498

its in my 305, pulls around 15 inches of vacuum at idle nice lope too

runs real nice

definately needed chip work and a '7747, with the stock chip it ran like crap

[This message has been edited by Pablo (edited November 30, 2000).]

[This message has been edited by Pablo (edited November 30, 2000).]

vortecfcar

275 advertised is about 224 @ .050, that is generally speaking. I have 226/230 on a carb and It is pretty hairy

------------------
91 RS W/carbed 350, Vortec heads, performer rpm, Comp cams Xtreme energy 280 grind. BFG Drag radials. 3.42 posi,Corvette servoed 700r4, ****ty stock converter
13.24@104

Tom 400 CFI

See Sig. Runs good idles smooth. would be impressive with better electronics (hardware and software.)

------------------
'83 Trans Am. 400 CID, 224/234 crane cam, Summit aluminum roller rockers, hand ported intake, home bored 2.09" (53mm) throttle bodies, MSD 454 injectors(75 lb/hr), Holley 255LPH fuel pump, custum modded FPR w/Vacuum port added, Edelbrock TES headers, empty cat, SLP 3" stainless steel cat back, stock ECM & chip. Borg/Warner T-5 World Class, 12" Corvette rotors and clipers, GTA 16" wheels, South Side Machine subframe connectors, 1LE sway bars, 3.45 ring and pinion, Alpine sound.
Best E.T. 13.532
Best MPH 102.24

airbrushguy

Pablo,
I have a '88 Camaro 5spd. W/ 1985 Monte Carlo SS 305 rebuilt stock using 88 TBI and all it's pullies and emission crap but using '84 T/A exhaust (big y pipe) and T/A's 3.73 disc rear. I did change the cam though, to a 214/224 dur.,112 lobe sep. and double roller tim. chain. All sensors are installed even the one in the air cleaner even though it is now an open element 14".
My problem is the idle sounds nice but if left idling for about 3 mins. it will momentarily drop from 800rpm to 500 for a couple of secs. then go right back to 800, sometimes this gets annoying(on a hill at a light!).
Crane says it's because the ECM is looking for vacuum since this cam only gives me 15 in., and I should get a TurboCity MAP adjuster to help this (TB city says it will give me 4-6 more inches of vac.) Has anyone else had this problem?
I'd like to get this eliminated before going on to AFPR, ultimat TBI conversion etc. any help??

chevyboy07 91

Crane is absolutely right man. Above a little x-tra duration the computer will start freakinhg out a little every once in a while. Every ligitamite cam swap I've done on computer cars does the same exact crap. And actually, a decent chip has been known to cure the trick.

------------------
Alex (AKA chevyboy) '91 RS 327 stroker, trans-go shift kit>> manual valve body, cat-delete, MSD (ignition, coil, 2-step, timing retard/ advance),Flowmaster, complete Edelbrock suspension including shocks, struts and lowering springs. CRAGAR drag wheels. Lowered 2.25" in front and 1.5" in rear....Best E/T 12.84 @109 mph...(got spray?)plus more!!

chevyboy07 91

Ohhh, and your first mistake IMO is going w/ a Crane. Comp puts a much better product out (again IMO).

Pablo

iTrader: (1)

airbrush guy, forget the map adjusters and other tricks, you just need a custom chip

that idle dropping thing is typical, my car did it too with the stock chip and yes its incredibly annoying its more often than not timing related. Not only is your car idling in an area where the timing is different than what it was when stock, but, you likely had to advance the distributor physically a rediculous amount to get it to run halfway decent(so it wouldnt backfire). I know I did, and the crazy amounts of timing that it added across the board including idle did the same thing your car is doing

fueling is also off and i can tell you this much, if you are on the stock chip and stock injectors you are going lean on the top big time, im running around 20 psi of fuel pressure and WAY more fuel in the chip than stock and i know im pretty close.

check out the prom burning article in the tech section of this website. Once you go to programming your own chips you never go back

airbrushguy

Actually the idle was fine, no backfire etc. I moved the timing up just to get better bottom end response, and lean on top? I don't know about that, the car seems to be outstanding above 2500RPM, also very responsive off the line with the timing now at 12degrees( didn't require any more movement of dist. than usual to get there either). Car runs great all around, has stock chip & injectors, just has this rare but annoying idle drop. Thanks for your suggestions, any more would be greatly appreciated.

airbrushguy

Oh, and if your suggestion is that I get a chip, who makes the best? I spoke to Hypertech and they blew me off by saying"anything we can give you won't solve your problem, the TBI needs 16 inches of vac. and until you get rid of that cam we can't help you!" ????

chevyboy07 91

Call those hyper-jerks and just ask about a whole bunch of crap>>>>>>>Then tell them "ohh, nothing you got will suit my needs"

------------------
Alex (AKA chevyboy) '91 RS 327 stroker, trans-go shift kit>> manual valve body, cat-delete, MSD (ignition, coil, 2-step, timing retard/ advance),Flowmaster, complete Edelbrock suspension including shocks, struts and lowering springs. CRAGAR drag wheels. Lowered 2.25" in front and 1.5" in rear....Best E/T 12.84 @109 mph...(got spray?)plus more!!

airbrushguy

Heh heh, yeah I hear you Chevyboy, but I'll still have my bad idle. Don't get me wrong , this car runs great considering how few modifications it has, and how little it's cost me to get it there. I would just like to get rid of that erratic idle problem.The car needs a lot of cosmetic attention this spring and summer so I'd like to get the mechanicals out of the way before then. Ed Wright says he can make a custom chip($350) for me that will help, he also says this cam is "a little wild for a 305",I chose it because it runs great in a 350 I built last year, and I have to agree with Pablo it does have a nice lumpy idle IN THE 305, that's probaly why I'm not going for the idea of pulling it out and replacing it with a smaller one just to cure the idle drop... not till I've run out of options, that is. Thanks

airbrushguy

C'mon, no chip etc. suggestions??

lars92RS

From what I hear my cam is agressive for a 305. But I really don't think it is. It is almost identical to Pablo's. (I didn't know that when I picked it out). Check my sig for specs.

Later,
Lars

------------------
'92 RS 305 TBI
K&N Open Element
Ultimate TBI mod's (thanks Pablo)
Cam[.442"/.465" x 218*/224* @ .050", 10:1 Hypereutectic Pistons
Performer Manifold
Shift Kit, Corvette servo,
and 2800 Stall Trans Specialties Converter,
Gutted Cat, IAT Resistor
MSD Blaster Coil, Accel Cap and Rotor