So I have a 1990 firebird formula 305tpi with a 700r4 and I'm thinking about doing a bigger cam, what would be the best size to use for my car it's basically all stock except for the cat back (minus the cat) also if I do a bigger cam what supporting mods would you suggest/tuning if any?

 

You need to upgrade CAI, full exhaust, first...
A big cam will only work best removing the TPI intake and heads you will need a tune and injectors
Then you better beef up the 700R4
Mileage???

 

Well the trans was rebuilt about 6k ago the injectors were done shortly after an they are bosch 3s would I need some bigger injectors? N I plan on headers n probly port the heads before the cam anyways. And this is still my daily so I don't want anything to crazy big

 

Oh and what is CAI?

 

Cold air intake

 

Oh okay sorry im not used to the forum abriviations yet lol but yeah I already have a CAI with a k&n filter

 

The Crane 2032 cam part # 104224 is a great add. Requires no special tuning, just an adjustable fuel pressure regulator and was designed for the TPI setup. Google it and search it on the forum. It has probably been the most popular TPI cam made.

http://crane.carshopinc.com/product_...d/15861/104224

http://www.youtube.com/watch?v=Yja12X-pCsI

 

get the crane 2032. i got it for my l98 but have read on here many places its one of the best for a the 305.

 

Thanks a lot guys as far as head porting n such would I HAVE to to make it run rite? And How much of a power gain would you estimate I'd be getting?
Oh and btw it sounds AMAZING! Lol

 

what gears?? I think for this application beehive springs would be great lighten up your valvetrain. as you will not have seat pressure issues like with fast ramp lobes
TB coolant elimination, if you can find a good deal on Billet pulleys
with a tune and your mods you will have a 13 sec car

 

Already have the TB coolant bypass and currently stock 2:73 but want to get a 3.73 or something how much do the valve springs cost? If you have a link feel free to post

 

You do not need to port the heads for that cam. It was designed as stock upgrade. Some upgraded springs would be a nice match along with some roller rockers.

You could expect a solid 40hp with the rockers without about 30 to 35 hp.

http://www.cranecams.com/88-89.pdf

 

Nice! I'll probly get the can next month with some of my tax refund money, anything else that might help me get the most out of it is welcome (surprised nobodys said "swap a 350" yet) lol

 

373s for a 5speed car and 342s for an auto TPI

 

I'm going to try to track A 3:43 rear pretty soon

 

The reason i wouldnt go much higher than that is . I went from 273 to 342 and now i barely have a first gear. Too much torque.

 

Ahh I see. How's it do off the line? And It still is y daily keep in mind do I don't need something too low just want a little faster launches

 

Off the line , feels like something back there is gonna break if i give it too much gas. LOL , yes it is my daily driver. You gotta think of rpms on the highway too. With the 273s , i was at 1200rpm at 55. WIth the 342's its at 1500. Going past 65 and it feels like i need to shift again. I can't imagine what 373's would be like on the highway.

 

i got a lt1 cam in mine was going to be for my tbi then my adhd kicked in now i have a tpi with ported n polished intake and heads and the shop threw in some springs for me!

lt1 cam 450 /420 lift for fifty bucks off the board i here it helps out tbis alot and gives them around 25 hp. so for tpis should do good! but for fifty bucks you cant beat it

 

I have heard the lt cams work but you have to gt the front machined down but yeah you can't beat the price

 

Lt1 cam is great for TBI, but the tpi cars mostly use the L98 cam which is almost identical

 

I've got 373 wit a t5 and at 60 mph I'm at 1900 rpm. I took it on a small road trip to Irvine KY the other day and got 22 mpg. think I might change it to 323 this summer jus to get the extra gas mileage cause I kno I will drive it more when good weather hits.

 

So what would be the biggest difference between the l98 cam and the crane cam posted above?

 

L98 cam specs are 202/206 duration@ .50 and 413/428 lift
CRane 2032 cam is 214/220 452/465

Plus that would be about as big as i would go with a computer controlled car. Any bigger and u might lose low end torque

 

remember stock springs only handle about .470 lift max too.

 

Yeah what I'll probly end up doing is getting the crane cam/adjustable fpr and the valve springs n roller rockers and just do them all at the same time do I know the springs will hold up to the new cam. Anything else y'all will guest will help ALOT

 

I do have another question, that particular crane can says for 87-89 considering mine is a 90 will this have any effect of if it'll work on my motor or not?

 

no

 

So it will work no problems rite?

 

yes

 

3.42 are the best gears for your T5. Which T5 do you have? If it came from an IROC the 5th gear ratio is .78. At 70mph will read 2150 with 3.42. If it came from a RS the 5th gear is .63 which will give you better gas mileage. At 70mph will read 1850 with 3.42. In my car with the .63 ratio with 3.73, at 70mph is 2150. Check the sig.

A 305 with a TPI mildly built needs no more than 3.42 with a T5 or Auto.

 

 

I have a 3.73 for my auto, I agree 1st gear is a little short....But its fun! If I had a T5...I would have went 4.10's
And I have the 2032 cam also installed in my car.

I love the combo! Remember to change your valve seals and change your springs while your in there too.

Don't wast your money on new roller lifters, your stock ones will be just fine.

 

Yeah that's actually what sparked this whole thing my car needs new valve seals anyways so I figured while imbdoing those might as well change the cam out btw I love the color or your TA

 

Thanks, Took a lot of time, but the Candy Apple Red looks killer on it!
Plus I shaved the door handles and took off the side moldings. It looks really good in the sun.

 

Hey guys newbie with a cam question. OK so this is what I have a 305 40 over. Heads are 1.94 in 1.5 ex some pocket porting under the intaka valves with "Z/28" (.500 max lift) springs with studs and full roller rockers. The intake manifold is fully ported. Stock injctors stock throttle body (52 or 58 mm throttle body coming as soon as I figure out witch to get). 2500 stall in a 700r4 3.73 gears with ZO6 vett wheels and tires. I'm getting the wheels once I have the motor running again. I already have to get a new chip since taking off the 9th injctor and porting on the intake. So what cam do you guys think? This is not my daily driver. Yes I KNOW a 350 would be way better but I just got the car block was already bored had the rockers. The heads were cheep $400 with the new valve and springs.