posting this for a friend and he has an 88 trans am GTA with a 305. I thought they came with 350's but the vin #'s say 305.

What OEM injector size did they come with and if he wanted to get bigger ones how does he mod the computer.

I only know LT1's so...... I thought he would have 22lbs and he's going to put on an LT1 intake ontop of 400sbc heads onto a 350 sb motor. I'm telling him to look atleast 24-28lbs injectors, but them the computer question comes into play. What is needed to make the new injectors work properly?

 

I believe all 305's came with 19# injectors. If the only change is the injector size, all he would need to do is change the injector constant.

 

what type of ECU promgramming would be needed. Cause i'm about to get him a LT1 intake with fuel rail, so it will come with 24lb injectors.

 

stock 305 is 19#..stock 350 is 22#..Stock LT1 is 24#...If he upgrades anything on the motor...ie. displacement, heads, cam, intake design, injectors, etc. he''ll need a new chip.. I know TPIS does good work and gaurentees them, but they're pricy. Check out thirdgen.org for DIY tuning. That would be your best bet.

Chris

you'll need to change injector constants, and with the LT1 intake fuel and spark tables, to get it to make max HP.

 

go to www.fuelinjection.com for the basics
go to http://www.classictrucksweb.com/tech...tpi/index.html for your injector sizing question, particularly questions 23-25
go to www.lt1intake.com to learn what a nightmare you're in for adapting that intake to fit on gen I heads
imho you're better off staying tpi, and upgrading if necessary
also, what 400 heads are you planning on using? the 88 and up tpi heads will stomp ANY 400 castings. hard to believe, but those 400 heads would actually be the bottleneck in your combination. it wouldn't be such a huge deal with a carbed engine, but it matters a ton in your case.
good luck with the 350!

 

TPIS sells chips off a shelf. I would never buy that. Get an EPROM that they burn custom for you and make mods. I did that with my firebird from LPE, Hightech Motorsport (chasis dyno) and www.fasterproms.com where the road is my dyno. I send fasterproms datalogs and they kept sending me new EPROMs till we all felt it was nuts on then I returned the old ones.

 

What? No they dont...all their programs are custom...I know that for a FACT!

 

well i talked to my friend and something is fubared. The 350 block doesn't have the same sensor hookups so he has to keep the 305 block, but sticking the 400 heads on the 305, i think he is making a big mistake, if he would have told me what he was doing i would have told him to buy a used lt1 and stick it into the third gen.

 

How do you make a custom program without the car present or without using feedback? I only know of 2 ways of making a custom chip. You make a rough program based on a SWAG, run it in the car on a dyno, do datalogging and then reburn. Repeat process till it is just right. The other way is to make the SWAG but use the road as your dyno. Same procedure. All reburns are based off datalogs.

Do tell how you plan to "custom" the program when you don't know what my car is doing? No 2 cars are exact so it is not like on an assembly line, is it?