305 Performance

[DaMoNe6969]

I noticed a lot of threads lately asking about 305 performance, So I thought i'de come up with one thread devoted entirely to making more power with your 305 tbi/TPI as a bit of a guideline for those who choose to do so..
First and foremost, make sure your engine/tranny can handle the added power and strain, If in doubt, a rebuild may be in order.. Also, make sure your braking system and suspension are both up to the task of added power..

First thing you should do to any engine is get more air in... A custom air intake (be creative) and a performance filter, k&n being the common choice.. Also, do a throttlebody bypass while your there..

exhaust system - a set of edelbrock TES headers, hi-flow cat, 3" exhaust and a performance muffler (Flowmasters are nice) This exhaust set-up will make a world of difference on its own..

After intake and exhaust, a set of performance pullies, they'l reduce accesory drag on crank giving you around 10 extra hp..

Injection system -
For TBI, I recommend the holley 670cfm tbi unit ontop of an Edelbrock performer intake,

For a TPI I would go with a BBK twin58mm throttlebody, throttlebody spacer and airfoil with an Edelbrock High-Flo TPI system (baseplate and runners) and some larger injectors w/injector spacers

Ignition System -
I prefer MSD so i'd go with MSD 8.8mm superconductors, blaster II coil, and an MSD 6AL ignition box, along with MSD cap and rotor.. I like Autolite spark plugs, they're dirt cheap and hold up very well in high hp engines..

Heads - A set of junkyard Vortec heads, with a valve-job and port and polish will flow Very well.. If you still want more, Im told World products 305 Torquer heads are the way to go

Cams - Best bet is to call up CompCams, let them know of your current mods, and have them custom grind a cam from their extreme energy series

After your mods, Get a custom burnt chip w/ 160 degree t-stat to get the most power out of what you've done..

Engine aside, the T5 trans doesnt like a lot of power.. Some have run them up to 400hp w/o problems, but for the most part, they'l calf out on you.. Might want to look at a built t-5, or a t-56 swap
If you've got an automatic, the proper torque converter, a Transgo Shiftkit and a corvette 1-2 servo will do wonders for shifting..
aluminum driveshafts also make a noticeable difference..

Anyone else got any comments, suggestions??

[Genopsyde]

Sure, these links should help out with TBI ppl.

New to TBI? CHECK THIS OUT!! *NOW WITH PICS!!!*

#1 MFAQ!! Open Element on TBI

Taking your TBI to the next level

Common TBI Mods and Info

[89IROC&RS]

http://www.chevyhiperformance.com/se...high&terms=305

tech articles from Chevy Hi Performance regarding the 305 camaro.

[DaMoNe6969]

A few websites that might be helpful to anyone that wants to look into doing their own prom burning

Originally Posted by Morley

get a cheap laptop, free scanning software http://www.moates.net/index.php?cPath=33 , A prom burner and prom adaptor http://www.moates.net/index.php?cPath=25 and a .bin editor. Learn about prom burning, get to know what is what on a prom chip and how to go about making changes and knowing what the changes do and affect. Try here for a good place to start http://www.eecis.udel.edu/~davis/z28/

[tcfco2005]

on the junkyard vortec heads you mentioned are there specific cars that came with those or do i just have to look

[bag91]

Here is a website that will help create a Ram/cold system for the TBI engine...I did this but instead of the funnel being in the turn signal light, I put it in one of the fog light holes and weaved a tube from the foglight to right under the snorkel creating a cold air box of it's own, once you
read you'll understand...
www.thirdgen.org/newdesign/tech/tbiramair.shtml

[IMG][/IMG]

[tripod12133]

Originally Posted by DaMoNe6969

I noticed a lot of threads lately asking about 305 performance, So I thought i'de come up with one thread devoted entirely to making more power with your 305 tbi/TPI as a bit of a guideline for those who choose to do so..
First and foremost, make sure your engine/tranny can handle the added power and strain, If in doubt, a rebuild may be in order.. Also, make sure your braking system and suspension are both up to the task of added power..

First thing you should do to any engine is get more air in... A custom air intake (be creative) and a performance filter, k&n being the common choice.. Also, do a throttlebody bypass while your there..

exhaust system - a set of edelbrock TES headers, hi-flow cat, 3" exhaust and a performance muffler (Flowmasters are nice) This exhaust set-up will make a world of difference on its own..

After intake and exhaust, a set of performance pullies, they'l reduce accesory drag on crank giving you around 10 extra hp..

Injection system -
For TBI, I recommend the holley 670cfm tbi unit ontop of an Edelbrock performer intake,

For a TPI I would go with a BBK twin58mm throttlebody, throttlebody spacer and airfoil with an Edelbrock High-Flo TPI system (baseplate and runners) and some larger injectors w/injector spacers

Ignition System -
I prefer MSD so i'd go with MSD 8.8mm superconductors, blaster II coil, and an MSD 6AL ignition box, along with MSD cap and rotor.. I like Autolite spark plugs, they're dirt cheap and hold up very well in high hp engines..

Heads - A set of junkyard Vortec heads, with a valve-job and port and polish will flow Very well.. If you still want more, Im told World products 305 Torquer heads are the way to go

Cams - Best bet is to call up CompCams, let them know of your current mods, and have them custom grind a cam from their extreme energy series

After your mods, Get a custom burnt chip w/ 160 degree t-stat to get the most power out of what you've done..

Engine aside, the T5 trans doesnt like a lot of power.. Some have run them up to 400hp w/o problems, but for the most part, they'l calf out on you.. Might want to look at a built t-5, or a t-56 swap
If you've got an automatic, the proper torque converter, a Transgo Shiftkit and a corvette 1-2 servo will do wonders for shifting..
aluminum driveshafts also make a noticeable difference..

Anyone else got any comments, suggestions??

Hey man i gotta question, What size wheel spacers did you have to get for your camaro to get those wheels to fit properly? Im gonna get some corvette wheels, the 5 spoke chrome ones and i dont know weather i need 2 or 3 inch wheels spacers. You have nice rims, so maybe yo can help answer this question for me

thanks
all the best
Marcus R.

[bag91]

I believe he said 3", I asked him too.
Id confirm with him just incase

[92EG6]

Originally Posted by tcfco2005

on the junkyard vortec heads you mentioned are there specific cars that came with those or do i just have to look

Chevy pickups 87 and up with TBI 5.7L are the most common they are a 1.94/1.50 head and SS valves for these heads are pretty cheap older manifolds don't work but Edel/Holley/Weiand all make good mani's for good prices. Most any 5.7L with centerbolt valvecovers are a vortec or vortec style head. TrickFlow makes roller tip rockers for them or Summit sells GM Performance Rockers for $60 the T/F's are $280. Std rockers will not work, they have to have a narrow body to work with the v/c bolts. I think TPI 5.7's 87 and up are vortec style heads as well but not totally sure.

[89IROC&RS]

factory applications for the Vortec style head are on Chevy and GMC trucks from 1995-2001, the VIN engine code for the 350 is "R" which can be found in the VIN as the 8th digit. stay away from big box trucks as they usually have the 908 castings which require extensive machine work to remove pressed in iron valve seats that restrict flow, and look for tahoes, suburbans, and silverados (or GMC counterparts) with the 062 castings that flow better as they are.

centerbolt 350 heads from 87-92 are L98 engine heads

centerbolt 350 heads from 93-97 are LT1 engine heads

at least in camaro applications. the heads on the trucks up until 95 had the same ports as the TPI heads, which used 30 year old designs. the Vortec heads are bad ass because they use LT1 ports on a small block chevy head, the LT1 head will not work on a standard small block chevy engine.

just wanted to clear up some details.

[89IROC&RS]

also, the junkyard Vortec heads are lift limited by their valve guide and spring seat design, they will only handle up to .480 lift as a maximum. if you will be running more than that, they will need to be machined down to accept larger valve springs and more lift. or you can buy a set of already modified heads from GM performance parts distributors.

[the sik1]

i need help making a 94 tpi work in my 86 Z28

[Nate355RS]

For TBI guys out there trying to get into tuning here is a step by step thread that will show you pretty much exactly what you need to do to tune your ride.
http://www.thirdgen.org/techboard/tb...free-tune.html

Also if anyone out there is interested in a serious TBI set up this is the ABSOLUTE BEST way to go, bar none. It is a long thread but well worth the read if you are serious about TBI.
http://www.thirdgen.org/techboard/di...-ultimate.html

[cwyates4]

how much difference would a 350 ci x-ram crossfire intake and 350 heads make on a 305?

[MrPbody]

CWYates,

350 Heads on 305 would reduce compression significantly, and you would lose power. While flow would slightly increase (305 heads aren't bad!), it wouldn't be enough to make up for the lost compression.

There's a website dedicated to the CrossFire injection, and the company has LOTS of goodies. We're building a 383 for an '84 Corvette right now, making over 500 HP for the street, using the CrossFire. I can't recall the name (I wouldn't be allowed to post it anyway...), but do a search and you'll find it.

A good friend has an '86 IROC with a TPI 305, and it makes over 400 horsepower. A real "sleeper"!

Jim