I have an 85 305 tpi. It runs 15.6 now but I want to be able to beat lt1's. The mods I have now are in the sig. What combo's should I look for? I've considered using NOS,but I would rather win on motor alone. Any help would be great.

------------------
85 305tpi Trans am
flowmaster exaust
K&N air filter, 4:11 rear gears
Best 1/8mile 9.842@71.1mph
2.232 60ft.

 

well knowing your transmission would help
but you have way too much gear for a tpi, i would say 3.73 max on a stick and 3.42 on an auto. plus what was your mph?
sticky tires would help that 60 ft time
headers are always great, then a cam swap with some intake/head porting should get you into the 13's
i think with a cam swap and some head porting and sticky tires i could run 13.5-13.7
right now i'm runin 14.43 @ 96 on street tires 2.16 60 ft, i have a manual with 3.08 gears
Andrew

 

Yeah, Headers, I gained 3 mph in the 1/4 due to headers alone. Headers, a cam, and a chip to take advantage of the cam and exhaust since the stock chip doesn't give you any fuel at higher rpms 4800+.before this SLP chip i was at 15.1 @ 93.65 mph. I'll post a new time probably this sat. coming up. I plan to go to Orlando again this friday night and run some 95-96mph trap speeds. most all stock LT1's runs less than 100 mph in the 1/4.

 

I know www.tpis.com makes an intake design similar to the LT1 design, this may put you right up there with the LT1

 

too much for a 305, the TPI longtube works better and for a 305 the TPI should beable to supply enough air unless you really start up the in the HP in which case the 305 won't last to long. There is a artical some where where then they got 400hp out of the 305 it threw a rod.

------------------
1987 Black 305 TPI 5spd IROC, seems to be fully loaded, but can't find RPO codes.

AIM: IROC 5spd
http://www.geocities.com/chevy5spdiroc/87Roc.htm

 

Look a 305 is only lacking 45 cu. in. to a 350. All is is about equal. Dont say a305 will die just because you are making HP out of it.

Here is the thing. If you want to compete with LT1s you need to buil about 330HP, because we all know the LT1s have almost all been modified in some way by now.

You need nothing lower that a 3.42 gear. That is a known fact.
Put a 2400rpm stall converter and a shift kit in your tranny, and do som minimal suspension work. I recomend LCAs and a Pan HArd Rod from Spohn. Not to expensive and well worth the money for take off and cornering.
Now that you can harnes the power let make it.
You need to build a nice flat torque curve. This is achieved by matching all you compnents together. LEts start from the Air Filter. You can use a conical open element K&N on the MAF and get cold enough ait without having to fab up anything. Then Modify your MAf by removing the screens, you dont have to cut the heat sinks out. They wont hurt you that much.
Then Get a 52MM TB, It will no longer be a restriction in you intake track. I know people are going to say you dont need it but trust me it will help. Period!
Then you need to port match your plenum to remove all the castin flaws and match it to your TB. After that don't wast your money on the Long Tube Runners because when we get to cam selection I will explain further of why you should By the SLP runners. Port match the plenum to match these and port your base to match also. There is a guy on here, forget his name, that does all of this porting work and supplies the Runners for a very resonable price. I myself did it myself.
Now the intake track is ready to flow,
Next we can talk about cam selection. Personally I like the SLP TPI cam available through Summit. SLP did a good job of getting their intake runner length tomatch the RPM range of the cam. Almost of perfect match to flow well up to 5200RPM and still maintain the original purpose of the TPI of producing killer torque on a 305.
With full exhausrt including Full length headers, high flow cat and your choice of cat backs, because they all sound differently but really all produce similar #s, you should be in the low 14's if you do nothing else.
From here you Tune.
You need to get an adjustable fuel pressure regulator and a Full ignition including a MSD box, or similar, high ooutput coil, and a good set of wires.
Then to crown it all off get a custom burnt Prom from either doing it yourself or from Ed Wright.
All this should allow your 305 to slay LT1s and atleast be competetive against an LS1 and maybe even beat the fer that are piloted by people that dont know how to Drive.


------------------
89 Trans Am Turbo 3.8L All stock 43,000 miles #1053 of 1555

Past Thirdgen:
86 Trans Am w/ built 355TPI with SLP goodies and too much other stuff to List. One sweet *** car, wish I would have had a good enough Job to pay insurance on three cars so I could keep it, but for a 89 Turbo Trans Am w/ Low miles, I think I made the right choice!

 

The 700r4 tranny has been rebuilt w/shift kit 10,000 miles ago. I've got the hypertech cap,coil,and rotor. Should i convert my cam to hydro-roller? Remember the engine is an 85.

------------------
85 305tpi Trans am
flowmaster exaust
K&N air filter, 4:11 rear gears
Best 1/8mile 9.842@71.1mph
2.232 60ft.

[This message has been edited by rdog30 (edited October 08, 2001).]

 

Hey Rick,
I think you should just buy my motor. haha Just kidding man. You've got some good info so far. Let me know if you need help doing some stuff. Later!

------------------
'91 GTA:
www.fbody.com/members/91WS6GTA

 

Using a stock style cam will be fine. The SLP cam worked great in mine. You ignition is good so far, but a MSD or a JAcobs box will really help matters. You might even want to consider having the heads refreshed with a 3 angle valve job and deck them slightly. A bump in compression couldn't hurt to much and with a hotter ignition and headers everything would be fine. There will also be some fine tuning issues such as chips, base timing, fuel pressure, spark plug gap, etc.etc.etc. to work on after the "big" mods are done. Then you can move into such things as tire pressure bla bla bla.
It can go on and on.

 

Hey Kyle, it's not the 45 cubes we're missing that's the problem, it's the smaller bore restricting head selection. That's why ford 302's make more power easier than chevy 305s. Anyways, you can stay with the non-roller camshaft, get a new cam though they're cheap for non-roller engines. Summit used to have an ad for non-roller 305 TPI gaining 45 hp with a cam and ADS chip.

 

yeah i know, i have heard it is a good imporvment over stock.

------------------
1987 Black 305 TPI 5spd IROC, seems to be fully loaded, but can't find RPO codes.

AIM: IROC 5spd
http://www.geocities.com/chevy5spdiroc/87Roc.htm

 

My friends have an 89 rs 305tbi. They said I could buy it from them for $200. I get the complete engine and belt system(convert mine to serpentine belts The block will be taken apart and new cam,forged rods and pistons will be put in. Not to mention bored .30over. Here's the question;will the the tpi stuff swap over? If not what needs to be done?

Thanks for all the help guys.

------------------
85 305tpi Trans am
flowmaster exaust
K&N air filter, 4:11 rear gears
Best 1/8mile 9.842@71.1mph
2.232 60ft.

 

The tpi should swap the center bolt holes will be at a different angle, so you would have to do some filing/grinding to make them line up right(not a big deal), but I've heard(rumor) that TBI heads are junk. I might be wrong and they might be the same as 305 TPI heads, so you may want to swap your heads over to that block as well(with a little port job and new valve springs(a must with a new cam)) then the bolt pattern would be the exact same anyways.

 

"Head selection is limited because of the smaller bore in a 305 chevy compared to Ford 302"

Thats proven but all this talk of making the 305 perform but I haven't heard anyone mention Vortec heads. I'm probally missing something here because up to yesterday I didn't give a rat's *** of the 305, I have a 383 stroker I'm almost done in my 87GTA. Now, I'm going to purchase a 305TPI 87 Formula for 2grand with converted over black leather interior from a 99 T/A, straight body, Car has less than a year with paint job, test drove the car runs strong with 155k on odometer second owner and my plans once I get the car is to G-Tech every modification and tune accordingly.

My ultimate goal is to run 13's NA with the stock shortblock. If it blows I have a 350 roller block just waiting to be re-build.

Here my recipe for stock shortblock 305 to run 13's.

Edelbrock E-tec aluminum Vortec heads 1.94/1.55 valves should fit 305 right?
Accel 211/219 cam
SDPC TPI baseplate
Large tube runner stock ported,TPIS or AS&M
Hooker emission legal headers with 3"catback
Custom prom tuning by self once I get acquited with how to do it
Cold air setup, ported MAF,52mm T.b., Adj fuel pressure regulator and all that minor bolt-on stuff.

Why or why not would Vortec heads fit or not a 305 TPI stock shortblock?

 

I think why the vortec heads haven't been brought up is b/c of cost issues iron vortecs $400+ plus vortec base $400+ that's ~$900 for just the heads, the heads you're talking about are close to $900-1000 theirselves. Most of these build ups for high 13s are under $1500 of total engine mods.(stock ported heads, stock base, stock TPI) I personally wouldn't spend a lot of money(like heads)for a 305 that wouldn't eventually swap to a performance 350 or 383.

 

440''/454'' lift cam
2200 stall
Edelbrock headers
125 shot NOS
8.02 @88.6 mph in the 1/8 w/ NOS
9.02@76.3 mph in the 1/8 N/A
NufNuffZ28@yahoo.com if you have any questions

------------------
1986 305 TPI
8.0 @88 in the 1/8
**Soon to be 355