Jake_92RS

So this summer I am going to make some upgrades on my L03 so it isnt so sluggish. Here they are..

-Edelbrock Performer intake manifold for TBI
-Comp cam (480/488, 258,264 dur; 112 sep)
+Valve springs roller lifters, and timing chain
-Rear end swap to posi with 3.73 ratio
-Hedman shorty headers with y-pipe

*Just installed a flowmaster american thunder 3" system so thats all set up.

Now a response to my original post on my upgrades said that I might need a computer re-tune for the throttle body after such drastic changes to the engine. Would someone please let me know what might need to be done when I do make all of these mods over the summer? Heres the original post:

https://www.thirdgen.org/forums/tech...ore-power.html

Thanks a ton!
FOR THE THIRDGEN ARMY!

robertfrank

iTrader: (27)

EBL Flash, WB O2 sensor and a good laptop with some patience. Yes you're going to NEED to retune after these upgrades. Here's some advice though. Skip the 3704 intake and go with a Performer RPM with a Transdapt Carb to Tbi adapter plate. The 3704 is'nt much better than stock unless ported. Don't go with the Hedmans. The Hooker 2460's and a Doug's D901 Y-pipe works and FITS much better. The Only thing you need to do is cut off the 2.5 outlet on the y-pipe and weld on a 3 inch. One more thing. Get a stall converter with that cam or it's going to be a DOG out of the hole. 2600-3200 would be much more fun and still be very drivable on the street. ( I know from experience).

Jake_92RS

Can I get a re-tune done at a shop? Honestly I have NO clue how to re-tune the computer on my engine, and do the hooker headers come with the A.I.R tubes?

robertfrank

iTrader: (27)

If there is a shop around you that can do it sure but I promise you you'll end up spending more money for someone else to tune it than you would yourself. The 2460's don't come with air tubes but it's an easy fix. If you want the emission headers the 2055's are much better but more expensive. Plus to get the most out of them you have to CAREFULLY port the collector ball flange as it is stupid small. Tuning really isn't that hard. It takes a little bit to get into but once you get the basics down everything will just fall into place. Plus the EBL FLash is an AMAZING tuning tool. If an idiot like myself can do it anybody can lol.

Jake_92RS

So after the adapter plate will that intake manifold be a direct fit for my LO3? I don't want to buy a part then not have it hook up to my engine incorrectly.

Fast355

iTrader: (2)

I wouldn't exactly call it a "DOG" out of the hole, it just won't build any real power over stock until you hit 3,000+ RPM. The 305 in the 80 Vette has a stock stalled 1.78 low gear ratio powerglide and 3.07 gears in the back. Its actually kind of funny to run against these newer cars that only run 30-40 mph in low gear with a car that is just getting up on cam at 45 mph in first gear and shifts at 5,000 rpm and 75 mph. One day I ran him in my Titan and I spun pretty badly in 1st gear, we sat side by side, I went through 2nd gear and actually pulled slightly, hit 3rd at 65 mph and he flew by and kept gaining, hit 2nd and jumped a car length ahead and kept pulling. Around 90-100 mph he was 2-3 car lengths on a very low 14 second/high 13 second Truck. So needless to say with a Crane 272 H10 cam the 305 has plenty of low-end power and the roller mentioned has shorter seat to seat duration and less overlap. I would concentrate on gears, locker of some kind, suspension mods and tires to hook the power before upping the stall.

rsmith085

iTrader: (1)

A good tune is a upgrade on a bone stock motor but after a cam/intake swap you'll need one for sure. GM used a real crappy tune for what ever reason, I've heard it was to keep these cars a lot slower than the TPI cars but that could just be a rumor.

That might be to much cam for the heads without machining the guides down. I think stock chevy heads max out around .460 lift before the retainer hits the top of the guide and thats a very bad thing. Your car should already have roller lifters in it being a '92 and it's safe to reuse them with a new cam as long as their in good shape.

ECU tuning is daunting at first but it's pretty simple once you've played with it some and understand the terminology used. If you can tune a carb you can tune a fuel injected car. Do lots of reading here and over at gearhead-efi.com and if still uncomfortable try to find someone local that knows about it to help you. Stay away from the mail order tunes they're more problems than their worth with a modded engine.

Fast355

iTrader: (2)

Usually you are safe at the .460 range, but better start checking by .470 range.

Aftermarket/Offset retainers similar to the ones GM used in the LT4 Hotcam package give you room in most cases for around 0.530" valve lift. I actually own a tool to cut down the guides in your garage with an ordinary drill. Works very well. I used it in combination with the offset retainers and properly matched springs to run .580" lift on vortec heads.

Fast355

iTrader: (2)

For ease of tuning I recomeend the EBL Flash or the later model TBI PCM and a Moates Autoprom. I would use the stock setup to learn how to tune the ecm and how everything works. That way when you toss heads and cam in the engine along with the additional fuel it will need to run to its potential you do not end up with a stumbling fuel rich, lean running mess.

rsmith085

iTrader: (1)

+1 on the later model PCM. The fuel and spark tables go all the way to 6400rpm and do away with the VE adder crap that the older ones use above 3200rpm if I remember right. You get more data, the data is updated at a faster rate than the older ones and to top it off the engine runs a lot smoother than it ever could with the older style ECU. I'm currently running one with a DIP socket soldered onto the MEMCAL. If I had the cash I'd definitely spring for a Autoprom it can be a pain sometimes burning and swapping chips to get things just right but it works. Just google 7747 to 7427 and you'll get so much info on the swap it'll make your brain hurt at first.

robertfrank

iTrader: (27)

I know when I had the stock stall after I did my H/C/I swap it was TERRIBLE out of the hole. Once I swapped in the Edge 3200 it was a night and day difference.

1991sleeper

iTrader: (-3)

If u can do basic 8th grade math u can learn to tune with the EBL ! I didn't have the slightest clue what I was doing when I bought the ebl (which I just got a month ago and still don't really know but it's a slow process) .. And like the other guy said a tune is an upgrade on a bone stock engine ! And that's the best way to start , get ur feet wet n learn how to tune stock THEN upgrade ur engine ! Mail order tunes r garbage and in my opinion ebl is better than leaving ur ECM in the floorboard and swapping out "chips" three times a day (PCM route) .. Go check out DynamicEFI.com .... There are gobs of info on this forum about tuning and RBOB the creator of the EBL along with everyone here will help u with any questions u could possibly ever ask along the way ! Just my $0.02