1985 IROC Z28 87' 305 TPI Lb9

ok well since right now i have the car torn apart and the original 305 almost out, iv kinda decided i do NOT want to install the TPI intakes on the new motor, to much of a pain...

so i was woundering what other intakes you gues are using on your EFI cars? what will work with my factory injectors and wiring harness? what keeps the egr?

should i go with a single plain style intake with an air only throttle body on top? or something like a tunnel ram where its front mounted?

iv never dabled with EFI before so this is not my strong area, just looking for sugestions UNDER $1000

as for mods to my car its a stock 87' LB9 with a comp cam(cam specs are in the link below), 700r4 with a b&m shift kit corvette servos and heavy duty clutches, the rear is a 3.23 9 bolt, but will be swaping it out soon for a 3.73 9 bolt. shoty edelbrock headers and high flow y pipe, high flow magnaflow cat and an american thunder series flowmaster cat back

cam i have > http://www.summitracing.com/parts/cc...ings/year/1986

 

This is the tpi section dedicated to Tuned Port Injection you might try posting in the alternative port efi intakes section.

 

oh im sorry i didnt realize there was a section for that

 

stealth ram would be your best choice, IMHO.

 

stealth ram is like $3500 was looking under $1000

 

Stealth Ram intake is $350 plue $250 for the rails and regulator, and about another $100 for braided lines and fittings to connect to your factory lines.

 

Yeah, the higher price for the HSR includes, all the electronics, sensors, injectors, computer, software, etc. etc. ....if you're already set up for TPI, all you need is the actual manifold and fuel rails, and some odds and ends. easily the cheapest outta the box solution. ...BUT...on a 305...I'm not sure I wouldn't just go with the TPI. It's no more of a pain than the HSR. A few more bolts, but honestly it's really not difficult. Even if you don't already have a TPI manifold, they're all over ebay and craigslist, and they're dirt cheap.

 

i have a complete TPI 305 85' IROC Z28, i was tearing the old motor apart because i have a new 305 with a cam and other minor work, was looking to free up some more high RPM power, i hate how tpi falls on its face after 4500, with my trans and rear i need atleast it to run happily to 5500-6000

 

which is why i was looking for a better manifold, to get more power. not just ease of installation

 

Basically a TPI with a 3.27 gear, or a HSR with a 3.70. Either way, they're gonna perform very similar. I'd keep the rear gear 3.27, and get a used TPI set up on the cheap. On a 305, it's not gonna make a whole lotta difference.

 

why would i need a used TPI setup when my i already have everything? my car was complete 100% original when i got it, just looking for an upgrade, and yes its a 305, but iv seen some 305s built up giving 350s a run for their money, thats why im building a 305, just to say i did lol, i dont care about all the hate for them and the arguement that i could have a 350 for the same if not cheaper, welllll i wanted a 305

 

So what intake did you decide on?

 

I don't know since no one has made a suggestion on an intake and throttle body combo for under $1000 that will work well with what mods I have and will work with factory tpi wire harness and what I would need to go with it such as injectors fuel rails fittings ect

 

Other then Holley stealth ram I mean

 

Stealth ram is a great choice.

 

I don't care what you build. You want a 305, cool with me. My point is that the HSR is too much, not needed, and will be a disappointment. Plus, the intake, the rear gear, the cam, the heads, all need to be a system. You already have a cam. Do that first, and put the car back together with the TPI and see what you think. No gears, no stealth ram.

 

cut me some slack im still learning, last build was a disapointment, over 4k into a motor for it to run 12s...... so thats why im asking here this time, not wasting $ again


and as far as gears and drive line, its a 700r4 with corvette servos, a b&m shift kit, a 2600 stall, currently a 3.23 rear but that is coming out before the car is driveable for a 3.73 i thought the 3.73 would be good for it, since the 3.23s make it feel like a dog

 

Look at it this way. Every piece essentially is a give and take. Some parts Like a TPI intake, make good low to mid torque, but sacrifice upper end/peak horsepower. Some parts like the HSR intake (especially on a 305) sacrifice low end torque for more flow/upper RPMs and peak HP. Grossly over simplified, but that's the idea. All parts favor a certain operating range, and all have to be matched to get the best performance. You already have the TPI, so lets just look at gears. The TPI is gonna be better off the line than the HSR, especially on a 305. The 3.23/3.27 gear was put on the car specifically to HELP the TPI up high where it starts to fall off. The TPI runs out of breath/gear, so the higher gear helps. A 3.70/3.73 will get off the line with a TPI even better of course, but you'll run out of gear even quicker! Not ideal at all. The TPI and the 3.27 are designed to work together, AND you already have both!

Lemme ask you this. Have you run the car yet with the new cam? Just change ONE THING at a time. Once you work out the bugs and drive it, see what you think. THEN look at changing the next thing.

 

its been 2 years since iv drivin my baby, sold it to my brother, he sold it, we found it blown up and abandoned, and no motors not in yet, just the rear and trans

the car originaly had a 2.73 rear, however iv never driven it with the 3.23s, i was told the 3.23 9 bold was a much better rear for tpi then the 2.73 10 bolt it had, is this correct?

and now the cam is in the air, possibly using a different but very very similar cam


i gues ill see how it does with the cam headers exhuast trans and rear before doing anything else, thanks Abubaca

 

Honestly, of all the mods we've discussed, the 2600 stall, and the headers/exhaust are gonna make the biggest difference.

....and the 2.73/2.77 rears were efficient, but not great for performance. They were just TOO high!!!! They were mostly in lower optioned 305's and a lot of the 350s. ....for a 305 TPI, a 3.23/3.27 or maybe a 3.42/3.45 would be ideal. If you already have the 3.27 9 bolt, go with that! ....and with the 2600 stall and exhaust, I think you'll be pretty happy.

 

Hi guys I have similar questions. I have an 88 LB9 getting tranny replaced now.

1: what should I have the shop do to the replacement before it goes in for a mild street car?

2: Gear question I had a 305 TBI with zz4 cam, TF heads headers 3.73, rpm intake car ran great but was still a 14.2 car I added a 75 shot and did 13.6s all street tires fun but like Blue1990 said for the money spent I was disappointed not just swapping a 350.

BUT 3.73 were way too much for this car. Fun off the line buzzing through gears on the street but I was banging at 6000 before engine had a chance to pull and that was on a TBI and with NOS it was hard to launch with such short gear. I noticed the most on the highway when I would run with other lt1. from 50-60mph roll punching it I felt like a honda civic screaming but going no where compared to the mod lt1 (cam headers) so I would say try the 3.23

I have a 2.77 9 bolt in my car. I hear it is a strong rear better then the 10 but gears are more $$$ and harder to find? I will probably do a 3.42

3: The performance mods. I am thinking the same thing port the stock heads, maybe buy a lower intake? is that needed? and cam and headers and hope I am in the low 14-13 range

Intakes? Hmm I tend to agree with other posters here. Port the TPI and probably be in same power range with any other intake? Unless you add fuel, do head work, bigger cam I dont think you you will see benefit of bigger intake? Port it out probably get a new lower intake maybe Siamese runners all will help match your bigger cam setup and headers and probably have a good matched combo with the 3.27 or 3.43