The penum was ported to the NOS plate.I removed the center to making it much easier to port.

Just got my scanner the other day

Nitro Don



[This message has been edited by Nitro Don (edited February 22, 2001).]

 

That looks great.
Are you going to extrude hone and thermal barrier coat the insides of the TPI now?


Don, aren't you racing with a 305?


[This message has been edited by The ODB (edited February 19, 2001).]

 

I'm running a 406 tpi with the stock plennum,slp runners, stock throttle body with trickflow G2 heads.
Now I've ported the hell out of the plennum and runners. But I didn't knock the center out of the front.
I know I need what all the air I can get, for the 406 but what I need to know is....would porting the opening of my plennum like that help any with a stock throttle body.....

 

enlarging the plenum helps feed the engine. The engine draws on the plenum air directly to fill cylinders.
Look at the LPE superram box intake, and then you make the call.

 

Enlarging the plenum also reduces throttle response.

------------------
Daniel Burk
http://www.isthq.com/~dan/fcar.html
'84 Trans Am WS6/L69
KB SFC, Moser axles, Torsen Diff. PST suspension, Braided stainless brake lines, Koni struts, 11-inch rear disks,Spohn Adj. torque arm,
Ported 305 heads w/1.94"intake valves, Comp Cams XE262H, Griffen alum. radiator,
Turbine Technologies 2500 stall converter, underdrive pulleys, Crane Hi-6 & more.
1.05g skidpad verified.
New best E/T! 14.039 at 100.82 MPH in 41 degree air at Stanton, Michigan.

 

Hey Don;

That building looks familiar. Where is it - on 46?

When are you going to the track? Let me know...

------------------
89 Firebird Formula
WS6 package,ZZ4 Crate engine
SLP 58MM TB, Edelbrock TES Headers
Random Tech 3" cat, SLP 3" stainless exhaust
9 bolt rear, Hotchiss swing arms, Lakewood panhard rod
Corvette 2/4 servo, kevlar band, full poly rear.
Centerline 16x8 rims, B.F Goodrich drag radials

 

ODB,
Yes I'm running the stock bottom 305.I've ran a best of 12.4 @ 109 MPH with stock heads,stock cam and stock intake.
After the swap my ET's droped,but my MPH went up to about 116-119MPH.I found my problem(thanks to you guys)that the valve lash was set way too tight(2 turns after 0 lash).After I set the valves correctly(1/2 turn after 0 lash) this car is idling and running like a totally new car.I also have a set of K-Motion springs that I need to install,that are good to .610 lift and have 130LBS.seat pressure,compared to my springs now =.560? and 100LBS.I running .544 lift which I think the springs are too weak and floating the valves.(power would fall flat at 5000RPM)
With this combo,and a beefed up 700R4 with a 9.5" 2800 stall TC,and the Nitto drag radials,and 175 HP nitrous shot,I HAVE TO BE
IN THE 11'S!!
NITRO DON


------------------
1990 Trans Am WS6
305TPI 700R4

ENGINE:
150hp NOS kit
March underdrive pulleys
Edelbrock headers(JetHot)
Mac off-road pipe
Flowmaster exaust
Jacobs ultra coil
K&N filter
Fulley ported base,
runners,& plenum
Crane AFPR
Hypertech airfoil
Crane 1.6 rockers
210/220 .533/.544 Cam
W/P Torquer heads
Edelbrock TPI Base
Edelbrock TI Runners
Edelbrock 52mm T.B.
TRANSMISSION:
Richmond 3.73's
Auburn posi
B&M Mega shifter
TCI shift kit
Vette servo
B&M 3-4 upshift kit
TCI Trans Rebuild
2800 stall 9.5" TC
Nitto Drag radials
FUTURE MODS:

BEST RUN:
12.48 @ 109.23 MPH
(with stock heads,cam,intake,and crappy Pep Boy's tires)


[This message has been edited by Nitro Don (edited February 20, 2001).]

 

I don't know how to get a picture of the lpe superram intake. I'm porting my intake this week. Do you think that would help with a stock throttle body though.

 

Z-BOSS,
Any kind of porting, whether from manifold-heads gasket matching, or the manifold itself, etc will help your engine to breathe better.

------------------
89 IROC-Z 350 TPI

-Flowmaster Catback
-Performance Resource Chip
-700R4 (Rebuilt) Too much done to actually list
-K&N Airfilters
-Ported Plenum
-2.77 Gears (not much to brag about but eh, its there)
-MSD 8.5 mm plug wires
-Problems every other day with the car (probably not a mod, but to me it sure makes a difference)

 

you might have to look deeper into what is going on when considering to take out the divider in the plenum. I'm not too sure what the problem with this is, but back awhile i had mine done the same way and i think it eventually came to the conclusion (with the help of vader) that removing the divider kind of works against the idea of having a tuned-port intake. When the air flows into the plenum without the divider, the air swirls around and throws the -tuned- part of the intake off. something to do with air pulses and the way the cylinders take in air......or something like that, just something to think about....

------------------
1986 Trans Am
305 TPI
"If it's not one thing, it's another!"
http://www2.hanover.edu/hierlmeier

 

86,

Good point (and good memory) but the nirto evaporator plate and nozzles kind of throw that all out the window. The turbulence created by removing the center divider is probably nothing compared to the drag around the gas pipes running across the bores. With a little more oxidizer thrown in there from the bottle, the loss would never even be noticed.

------------------
Later,
Vader
------------------
"No matter how hard you try you can't stop us now..."
Adobe Acrobat Reader 4.0

 

It sounds like you have a rather potent 305!!

Did you port it with carbide bits or the regular "sand" ones?

I see that you and LeeH are local (to me) are you going to the SLP gathering at Englishtown?

 

Hey Lee,
The burnout pic was taken almost 4 years ago in Boonton.I had just raced it for the first time a day earlier,to a best of 15.6 @
an incredible 86 MPH

Omega,
I havent heard anything about an SLP event
at Englishtown.Yeh,I'd go.I wanted to do one of the GMHTP shoutouts last year,but never got the chance.
I usually go to Island Dragway nowdays cause the lines are short.Sitting around for 2+ hours in staging is not fun.
Nitro Don

 

Guys the divider just extends the plenum. It does nothing. It gives the same swirl turbulance as if it were just at the Throttle Body becase it has the same profile on the back of it. Removing the center section does nothing but allow more air to be stored in the penum. So for WOT drag racing with a 406 yes. Street driven 305 NO, the loss in response is not worth the little bit you might gain at the track. Remember your not gaining that much room anyways, but like I always say, want Ten more HP, find 1HP in 10 Different places. Its much easier that way.

 

Kyle is right about the plenum divider being pretty much useless. The response should actually stay about the same because the 16"+ runner length & crossection remains unchanged. An enlarged plenum area might require a slight change in tuning of transitional fuel delivery, but really shouldn't be a big difference either way helping or hurting.

If I modified my plenum like that I would definately block off all the little passages (PVC, EGR).

Don, that is a great running 305. My 86 only went 16.3 @ 80 MPH with the peanut cam, 700R, and 2.73 gears. After several years of torture working with the TPI it finally went 12.95 @ 102 mph on some Sportsman Pro's.
After that I ported the stock heads, changed the camshaft, and put it on Crack. It improved to 11.8 @115 mph on MT Competitors. I had it tuned extremely lean (250 mv on the O2) which made a bunch of power on pump gas. That lasted about a month until I went into overdrive (in a streetrace for $$) on the Crack, which sent a cast piston to an early grave. I still won the race, but went home on a flatbed.
After that I ditched the TPI as it was ultimately the cause of every problem I'd had up to that point including the broken piston.
I will be bringing the .030 over 305 out this year with a carbureted setup which should run over a second quicker if things go well. I love the 383 in the camaro but I have missed the 305. The little 305 has pi$$ed off more people than the Clinton administration.
If you want some good hints on power from the TPI, just shoot me an email and I will give you some stuff this weekend.

great to see someone else seriously racing with a 305!

ODB

 

Omega -

What Don said : I havent heard anything about an SLP event at Englishtown. Yeh, I'd go. I wanted to do one of the GMHTP shoutouts last year,but never got the chance. I usually go to Island Dragway nowdays cause the lines are short.Sitting around for 2+ hours in staging is not fun.
Nitro Don

When is it? My bird seems to be running pretty good now - but I need to set it up after massively porting out the plenum to match the 58 mm TB - idle is way high now, timing is off, and the tps is acting up too...

Nitro - My prom burning stuff should be here tomorrow, and I picked up a couple of spare memcals to convert ($20 each at Royal Pontiac in Pompton Lakes - cheap or what?) LEt me know what you need and I'll see if I can do it...



------------------
89 Firebird Formula
WS6 package,ZZ4 Crate engine
SLP 58MM TB, Edelbrock TES Headers
Random Tech 3" cat, SLP 3" stainless exhaust
9 bolt rear, Hotchiss swing arms, Lakewood panhard rod
Corvette 2/4 servo, kevlar band, full poly rear.
Centerline 16x8 rims, B.F Goodrich drag radials