vortecfcar

Its been a while guys but I need some help here. Me and my buddy were bored this weekend so we decided to throw a cam I had laying around in his '89 K20 (has headers and dual cats with dual exhaust). We finished it up tonight but upon test driving didnt notice the gain we were looking for. The truck seemed to leave good but kind of lay down on top. Also it smelled like rotten eggs at the exhaust after running it hard for a bit.

I guess we need to boost fuel pressure and set timing (which is now at 0 with connector disconnected). Where should we be as far as timing and should I just put a quarter under the FPR?

thanks a million for any help

palric

iTrader: (1)

If the application is computer controlled L05 TBI then the 214 degrees of duration on the intake can be some trouble -- from my past experience I would not go beyond 212 degrees of timing on the intake (on a 350, less on the 305) if you want the vehicle to run in closed loop. There will likely be chip issues as well.

GM TBI motors are EXTREMELY sensitive to cam intake duration. To test this check the vacuum in inches at idle with the new cam against the minimum required by the MAP sensor (factory).

have a nice day, RP.

lars92RS

Once again parlic speaks the truth. You will need more timing with that cam. Go ahead and hook a vacuum guage to it and addvance the timing (at idle)until you get the highest vacuum you can. This will be optimum setting for what you have. I would really worry about the fuel too much. As long as you have a *** o2 sensor your computer should adjust for it. If you have the ability to burn chips, it would be greatly bennefical.

-lars

Brian Felts

The timing should be around 4 to 6* the Vac gage will be a good help. I would think you may need to raise the fuel pressure a little. I did the adj. mod to mine and it worked wonders. (its so easy to make your own) With that duration you will need a little more fuel to charge the Cyl's.


Brian

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1989 Camaro RS

305 .030 over Hydro Pistons
Vortech heads milled to 58cc...Performer RPM intake....LT4 cam..Crane Gold rockers...FastChip custom chip...ALum. Driveshaft...3.73 gears with Posi...underdrive pullys...Rebuilt 700R4 with Vette Servo and B&M shift Kit...MSD ignition...A/C Delete No SMOG junk....1997 SS leather interior...B&M Shifter... Ultimate TBI mods...14X3 K&N open Element Non-Drop...Hooker headers....3" exhaust with Flowmaster Cross flow 16X8 Wheels from 97 RS Spohn LCA's Spohn Panhard Bar..LETS PLAY FORD!!

www.geocities.com/feltsb

Pablo

iTrader: (1)

brian is right about the timing

thats the cam in m 305 btw and after some chip tuning the car screams
youll definately need to start writing your own chips

AJ_92RS

Could the rotten egg smell be from the catalitic converter going bad? If it's clogged up then that would explain some of the acceleration problem. Or could that smell just be from the cat getting an improper A/F mixture?

I don't know much about cats, so these other solutions may be all that's needed. It's just that I've smelled a bad cat before. Just my 2¢.

AJ

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92 RS w/t-tops 305 TBI Auto.
170K miles and don't burn a drop o'oil
-K&N Truck filter #1500 w, open ele.
air cleaner
-Dynomax 2 1/2" cat-back
-B&M TransPak
-Jet Stage2 Chip
-180* T-Stat w/ 185* Fan Switch
-JVC CD--Alpine speakers & 4ch. amp
Rockford Punch 100. 1 - MTX 12" sub

[This message has been edited by AJ_92RS (edited September 03, 2001).]

Dyno Don

iTrader: (7)

With that cam the kpa will be so high at idle it will be dumping excess fuel. The smell is the cat trying to burn up the raw fuel, if the situation persists it will kill the cat(runs to hot and will melt it).

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Chronologically challenged. But still kicking!
'92 CAMARO RS
305 TBI 5/spd (now TPI)
B4C Alt.
'69 camaro-BB/Lenco,1050 dominators, /Pump Gas/no drugs 8.97-150+/3200lbs.
SoCal Thirdgen F-Bodies

JPrevost

Time to start burning your own eproms!
This is a speed density EFI system, every little change needs a new chip and a cam swap is a BIG change. You can mess around with fuel pressure and probably get away with using a vacuum adjusted fuel pressure regulator.

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, Jon (350 TBI!)
91 Red My website

vortecfcar

hey guys, sorry I havent been around. I left and went to school, I told my buddy to put my old 4bbl and HEI setup on the truck (I was running out of options). Im simply not into fuel injection enough to buy my own prom burner. If I decide I want to fool around with the truck and try to get it back to proper running condition with the TBI Ill keep what you guys have said in mind, but for now its just easier for me to tell him to carburate it

thanks again, nick

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91 RS W/carbed 350, Vortec heads, performer rpm, Comp cams Xtreme energy 224/230 duration and .477/.480 lift. BFG Drag radials. 3.42 posi,Corvette servoed 700r4, 3000rpm stall converter. Edelbrock TES, 3inch cat, flowmaster with single 2.5 inch exit.
Best time yet to come
13.0 @ 107- N/A
12.5@ 117- 100HP Nitrous

This is a Pic of my car in race trim www.tbns.net/billyjay/camero.jpg

Yes I know how to spell camaro- so dont ask. I didnt make the link