Okay, bone stock with my car I happen to run a 14.4 @ 94mph. Not bad for a 305 stock I say. So I install my headers and catback and guess what I run? 14.4 @ 95mph. Okay, aren't I supposed to maybe drop a tenth or so? I gained a mph that was it. I know there is something wrong here...anyone else have this problem?

------------------
1990 G92 5spd LB9 - 3.42

Accel Ignition/Wires (8.8mm), Advanced Timing, TB Bypass, Ported and Gasket Matched Plenum, Synthetic Motor Oil, 160 Thermo, TPIS Airfoil, K&N Air Filters, Centerforce I Pressure Plate and Clutch, Edelbrock TES Headers, Dual Cats, Edelbrock RPM Series Catback, Homemade Ram Air

14.4 @ 94mph w/2.0622 60ft

Soon To Come

AFPR, Underdrive Pulleys, Short Throw Shifter, Intake, Cam

7-1 Against Rustangs = )

 

raise fuel pressure to compensate for more air flow in and out of the engine.

 

how many miles are on your engine?

 

and just by looking at your trap speed you gained around ~10hp. that would mean your stock exaust manifolds and exaust were not choking your 305 very much at all.

 

80k miles and no, how would i gain 10hp by ONE mph gain. Dood, there is something wrong here because headers should improve flow, I don't have the peanut cam as I have G92. Something is very wrong here.

------------------
1990 G92 5spd LB9 - 3.42 80,000 miles

Accel Ignition/Wires (8.8mm), Advanced Timing, TB Bypass, Ported and Gasket Matched Plenum, Synthetic Motor Oil, 160 Thermo, TPIS Airfoil, K&N Air Filters, Centerforce I Pressure Plate and Clutch, Edelbrock TES Headers, Dual Cats, Edelbrock RPM Series Catback, Homemade Ram Air

14.4 @ 94mph w/2.0622 60ft

FOR SALE! Email me for further info.

 

maybe your intake is blocked somewhere. Find restrictions to flow and remove them. maybe no air is getting past the foglights up to the engine. there can be some very tight squeezes through that cold air path. maybe a simple tube with a round k&n would be better as a cold air intake.

------------------
-Tas
'89 Formula WS-6

305, TBI, auto, 14x3 chrome flat based open element with K&N, Milodon 160* thermo, functional Formula hood, cross-flow Flowmaster, '99z28 rear pipes and tips....

Soon to be installed:
Hooker 1-5/8" 50 state legal headers, Dynomax 3" I pipe (PN 44063 and 43248), Catco 3" cat, and injector spacer.

Super GRK_Taz World
F-Body Dual Exaust
EFI & Intake Options
AOL IM: superGRtaz

 

maybe...but could that result in only 1 more mph gain? i told my friend that at the track and he said it should be okay, i did notice tho before i took my old exhaust off that it had a 3" catback before but shouldnt i still see more gains from just headers?

------------------
1990 G92 5spd LB9 - 3.42 80,000 miles

Accel Ignition/Wires (8.8mm), Advanced Timing, TB Bypass, Ported and Gasket Matched Plenum, Synthetic Motor Oil, 160 Thermo, TPIS Airfoil, K&N Air Filters, Centerforce I Pressure Plate and Clutch, Edelbrock TES Headers, Dual Cats, Edelbrock RPM Series Catback, Homemade Ram Air

14.4 @ 94mph w/2.0622 60ft

FOR SALE! Email me for further info.

 

Well, what type of weather did you run the 14.4 in? It is pretty warm now and maybe you ran the 14.4 before in cooler weather.

Humidity can affect it.

Weather plays big role.

------------------
-86 IROC
S-Trim, Speed Pro, AFR
this years goal: 10.50 @ 130+ mph
-=ICON Motorsports=-

 

Rule of Thumb:

1 MPH = 10 HP

 

um yes. you gained 10hp like i said. your trap speed increased 1mph. each mph equals 10hp.

 

youve only got 80k miles, go with a 100hp shot of a PROPERLY INSTALLED nitrous kit, with a throttle switch, a toggle switch, and make sure its a wet system which injects fuel with the nitrous. remember, nitrous doesnt blow motors, abusing nitrous does. ive ran a 150hp shot on my old 350 from 20k miles all the way to 168k miles (with LOTS of 1/4 mile passes). there is no better bang for the buck.

 

I like naturally aspirated motors. It's no challenge if I get nitrous.

------------------
1990 G92 5spd LB9 - 3.42 80,000 miles

Accel Ignition/Wires (8.8mm), Advanced Timing, TB Bypass, Ported and Gasket Matched Plenum, Synthetic Motor Oil, 160 Thermo, TPIS Airfoil, K&N Air Filters, Centerforce I Pressure Plate and Clutch, Edelbrock TES Headers, Dual Cats, Edelbrock RPM Series Catback, Homemade Ram Air, Bosch +4 Platinum Plugs

14.4 @ 94mph w/2.0622 60ft (w/o headers and catback)

14.426 @ 96.19mph w/2.167 60ft(w/headers and catback)

FOR SALE! Email me for further info.

 

PLugged Cats?
poopy exhaust?

 

its no challenge? it just adds to the fun factor. your stock exaust manifolds werent causing your 305 much restriction. thats why you only saw a ~10hp gain. the stock 305 long block doesnt move enough air to begin with to need headers that bad. what kind of cat converter are you using? if you are using your stock cylinder heads, id suggest upgrading with some good 58cc combustion chamber aluminum heads that move more air than your stock heads will. that will take more advantage of your headers. dont forget to port/replace your intake manifold while you are doing the heads.

[This message has been edited by whiterocz (edited July 01, 2001).]

 

How the heck are you running 14.4, that pisses me off, my freakin 350 is only running a best using the G-Tech of 15.86 @ 93 mph, the only thing I can figure my 1-2 shift drags out and I am having that looked at soon when I have my 3:73's installed.

------------------
'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
FLOWMASTER
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
2:73 GEARS
Rebuilt 700R4, with manual valve body
B&M Megashifter
Soon to be installed
Exhaust Cut-Out and different gears, either 3:73 or 3:42
"There is nothing more addicting than speed"

 

How the heck are you running 14.4, that pisses me off, my freakin 350 is only running a best using the G-Tech of 15.86 @ 93 mph, the only thing I can figure my 1-2 shift drags out and I am having that looked at soon when I have my 3:73's installed.

------------------
'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
FLOWMASTER
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
2:73 GEARS
Rebuilt 700R4, with manual valve body
B&M Megashifter
Soon to be installed
Exhaust Cut-Out and different gears, either 3:73 or 3:42
"There is nothing more addicting than speed"

 

Mark, its all about balance and tuning. If you are only squeezing high 15's out of your 350, you must look at your whole system and assess it. Look at rear gears, look at transmission. Look at the torque converter. Look at the compression ratio, the cam, and the heads. Look at the valves in the heads. Look at the induction system. Look at the ignition system. Look at the exhaust. Look at the size of the primaries on the exhaust, and the size of the collectors. It all matters, and they must all be synchronized with each other in order to make power. You must decide on where you want to make power.

First, inventory your parts, and draw up a theoretical power curve for each piece. Do you have a factory TPI? Power curve = 1200 to 4200 RPM. Does your header have a 1 3/4" primary tube on a 3" collector? That's a 2500 to 6500 RPM piece. See the mismatch? Now, this is just a theoretical example, but it illustrates how you need to look at your current system, and decide which pieces might need to be replaced in order to get the rest of the pieces running at their potential.

BTW, see the SIG for the E/T of my original 135,000 mile 305. It's a little shy on torque off the line, and I expect that if I move up 300 RPM on the stall converter, I'll drop another quarter second. I didnt match the converter as well as I'd hoped :/

Oh yeah, I forgot: The reason I looked at this thread is that I'm using Edelbrock TES # 6872's and they seem to work for me!
------------------
Daniel Burk
View my third-gen hobbyist performance page!
View my reader's ride!
'84 Trans Am WS6/L69
KB SFC, Moser axles, Torsen Diff., 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.
Best of 14.039 at 100.82 MPH in Stanton, MI
New!Full 1LE brake upgrade! Details at website above.

[This message has been edited by ws6transam (edited July 06, 2001).]

 

Well my engine, is rated at 250 hp with a q-jet, hei distributor, cast iron intake and open headers so I figured I would be a little above that rating and that is with 304 ft/lbs torque at 3500 rpm. And granted my 2:73 gears aren't helping but I would think I could run a little faster. Here's what I think before I had to get my tranny rebuilt the car seems to pull a lot harder, now it doesn't as the 1-2 shift drags which I feel is hurting me a lot, that is why I am having the tranny looked at, hopefully that is what is messing with my 1/4 time.

------------------
'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
FLOWMASTER
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
2:73 GEARS
Rebuilt 700R4, with manual valve body
B&M Megashifter
Soon to be installed
Exhaust Cut-Out and different gears, either 3:73 or 3:42
"There is nothing more addicting than speed"

 

The Edelbrock headers are your problem. Edelbrock makes the worst headers I have ever seen. I swapped from those junk TES on my old 305 to a "true" 1-5/8" SLP Tri-Y headers and picked up about 1mph and dropped 2 tenths. I'm actually still using them on my current 355 but not for long. Hooker LT's just came back from JetHot!!




------------------
David Tuschhoff
1991 RS Camaro M5
A SuperRammed, TPIS,
Ross, AFR, Scat, Crane,
CompCams induced 355!
My f-body page!

 

Hey Mark........
I have the WORST TPI motor ever offered from GM and am getting 15.62 @ 86-87 mph. Just a peanut cammed 305/A4/2.77 WS6 TA with full insides.

Your 350 is not the only one I've seen that is slower. I do believe I'm above avg. driver for now. I guess 600 passes down the 1/4 does that. But 450 of those passes was in a Hunder 4 pooper.

------------------
86 T/A 5.0 A4 & 2.77 gear
15.62 @ 86 mph
93 Civic 1.6L
13.5 @ 100 mph

 

Yet my car was 6mph faster, could that be do to the time I lose on the 1-2 shift but I make the speed up the rest of the way.

------------------
'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
FLOWMASTER
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
2:73 GEARS
Rebuilt 700R4, with manual valve body
B&M Megashifter
Soon to be installed
Exhaust Cut-Out and different gears, either 3:73 or 3:42
"There is nothing more addicting than speed"

 

Gtech's read MPH around 5-6 too high compared to a track (because of the way the track reads it as an average over short distance at the end, can't remember the distance).

You can't compare jack with your Gtech though really. Elevation changes in the road and how you have it setup on your windshield can throw evertying way off. You need to run at a track. If you run a 15.8 with a 350 at the track then you have some stuff BAD wrong. (unless you're at really high altitude, still slow though IMO). The TES headers are not your handicap.



------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

 

Okay I'm convinced.

Dave, Specifically what is wrong with the TES headers? Could you back up your claim with specifics?

I'm finding mine(The 6872-series) to be pretty decent, especially for only $300, including Y-pipe. I picked them up from TPIS, and painted them with $12 worth of VHT1600 aluminum paint. They are now into their second season with no hint of discoloration or rust. They seem to be a decent budget priced header.

 

Dan, search this board. I've explained it many times. From their small ports, weld all around the ports, bad welds, the dual size tubes (which they've now fixed, they're all 1 5/8" now), and various other little things.

 

Kevin pretty much summed it up. The flanges were horrible. The welds are just not very good at all. The SLP's are so much cleaner, with a nice square shape. I didn't have a problem with leaks and plug access was actually a bit better on the Edelbrocks, but the track doesn't lie. I pretty much picked up a solid 10hp and a good bit of midrange just by switching headers and nothing else on my old 305.



------------------
David Tuschhoff
1991 RS/Z28 Camaro M5,
Fuel injected 355ci V8.
12.55 @ 111.6mph 1.94 60'
My f-body page!

 

how many runs have you done with and without headers? doing one run with and one without is nothing to base a comparison on. it all depends on your launch, 60', and how well u shift. i have had days when i go to the track and my first run is like 14.9 and by my last run im pulling back to back 13.8's. On top of the human factor, tire pressure, humidity, temperature, suspension setup and a miriad of other factors come into play. also, have you replaced your cat??? it might be blocked. just gut it and swap a heated O2 sensor in. make sit much louder and i think it adds a decent amount of speed. is your timing right? how are ur plugs and wires??? finally, what kind of cat back do you have???

dont belive the crap about TES's being horible, there are better headers out there but the TES's are just fine for a mild TPI engine.

------------------
1988 IROC-Z L98
License Plate: STG KLR 1
Engine Mods:
Edlebrock TES Headers, Hypertech Chip, Flowmaster Muffler, Intake Airfoil, Removed MAF Screens, MSD-6A, MSD Blaster 2 GM Coil, bored .030 over.
Nitrous System:
NOS Plate Kit, 100hp shot.
Suspension Mods:
Lakewood Traction Action Lift Bars, Hal Rear Shocks
Trans Mods:
2,500 stall converter, Redline clutches,Heavy Duty Steels, Trans-Go reprograming kit , Heavy Duty 2-4 band, Corvette Servo, B&M Mega Shifter
ET: 13.833@99.30 N/A

"If you can put it on your car, its fair" Quote By Guido
Foundering Member of the Illinois Overkill Crew (IOC)
www.mfba.org

 

Ok, I feel like a dumbass.....I thought he was referring to me!! Sorry 88blkroc!

------------------
David Tuschhoff
1991 RS/Z28 Camaro M5,
Fuel injected 355ci V8.
12.55 @ 111.6mph 1.94 60'
My f-body page!

[This message has been edited by David 91RS/Z28 (edited July 10, 2001).]

 

I believe he was referring to the original post...

------------------
Ray87Z
-Vortec headed 350.
86 IROC w/ a cammed 305 TPI.
Formerly Ray86IROC.
www.inter-scape.com/Ray

 

Doh!! I just edited my last post!



------------------
David Tuschhoff
1991 RS/Z28 Camaro M5,
Fuel injected 355ci V8.
12.55 @ 111.6mph 1.94 60'
My f-body page!

 

I did about 4 or 5 runs with headers. and about 6-7 w/o headers. i shift pretty fast, another thing for my ets, my centerforce clutch was just broken in at like 515 miles. it wouldnt snap into 2nd, it would hang a tad causing me some speed. tire pressure was good, humidity was kinda high, temperature was high, suspension sux along with tires, and im replacing my cats with my next paycheck. im gonna remove all air equipment and just replace my dual y pipe w/cats to a dual y pipe w/o cats. and my plugs are bad, i have to get some ac delcos. i was just pissed because i only gained atleast 1mph each run. i got mad after spending $700 and seeing no drop in ets, although i know my 60ft had been a 2.0 maybe 14.3's if thats what my mph should run.

------------------
1990 G92 5spd LB9 - 3.42 80,000 miles

Accel Ignition/Wires (8.8mm), Advanced Timing, TB Bypass, Ported and Gasket Matched Plenum, Synthetic Motor Oil, 160 Thermo, TPIS Airfoil, K&N Air Filters, Centerforce I Pressure Plate and Clutch, Edelbrock TES Headers, Dual Cats, Edelbrock RPM Series Catback, Homemade Ram Air, Bosch +4 Platinum Plugs

14.4 @ 94mph w/2.0622 60ft (w/o headers and catback)

14.426 @ 96.19mph w/2.167 60ft(w/headers and catback)

 

it would appear you are being robbed about a tenth of a second by your lesser 60ft...

which also helps to explain the small MPH gain...

try again with better tires and a cooler day, i think you will see some change...

 

That car came stock with a 305. I think thats what you have, unless someone swapped it out

Also, get rid of the cast iron intake

PS
Anyone who has TES and thinks they're junk, email me...I'm looking for a cheap set



------------------
Mike L.
It ain't pretty.......

1987 IROC Z TPI 350 A4 3.27 Borg-Warner.

Mods: 2300-2500 Stall Converter, Shift Kit(GM parts), TPI Specialties Stage 3 PROM, Modified Airbox w/ K&N's, homemade cold air, Relocated MAT sensor, Gutted MAF, 160* thermostat, Accel 8mm Wires, bypassed TB coolant, Flowmaster 3 chamber single 3" in/out muffler, 3" MAC mandrel intermediate, custom dual !cat Y-pipe. airfoil, ported plenum. !smog

http://www.MichaelLasiuta.home.att.net

**BOYCOTT LAPEER DRAGWAY**

 

I had the 350 GM motor put in, and I have the stock aluminum Z28 intake, it's just that the motor dynoed by GM was using a cast iron one.

------------------
'86 IROC
T-TOPS, TINTED WINDOWS, BRAKE LIGHT BLACKOUTS
GM GOODWRENCH 350
EDELBROCK TES HEADERS
FLOWMASTER, NO CAT
EDELBROCK 600CFM CARB.
KN AIRFILTER
ACCEL HEI DISTRIBUTOR
160* Stat
2:73 GEARS
Rebuilt 700R4, with manual valve body
B&M Megashifter
Soon to be installed
3:73 Richmond Gears and 3" Exhaust
"There is nothing more addicting than speed"

 

Check your O2 sensor.It might need replacing since not a lot of people think about it. It'll free up some power that you thought you never had.Not a major difference,but noticable.

------------------
"A musclecar, by definition, is a powerful and sporty vehicle that must be able to spin its tires at will. The Firebird Trans Am is capable of laying down twin black streaks of rubber several hundred feet long. We wanted to be sure it could, so we did it a half dozen times in the name of automotive science."-MotorTrend