Drag racing experts - lost mph/et on big end

[knudsonm]

Drag racing experts - lost mph/et on big end



After asking about weight reduction to help out my ET's on other boards, some members have noted my time slips look funny. While I will agree that my engine combo is completely hosed, it is what I have to work with right now. Any comments or suggestions??? What kind of gains should I be seeing going from 1/8 to 1/4?? Is it the "barn door" effect??



Best timeslip so far was:

60' - 1.520

1/8 - 7.193 @ 93.320

1/4 - 11.43 @ 114.286

Otherwise it runs 11.60's-11.80's depending on weather and track prep.



This happens to be a '90 2wd 2dr S-10 Blazer with an aluminum headed 454 BBC(425-450hp maybe).



Engine: 454 BBC

Modifications: stock '97 454 shortblock, heavily ported Edelbrock Heads(flowchart below), Edelbrock RPM Air Gap intake, Holley 850 DP, Lunati Voodoo Hyd roller cam(231/239 @ .050, 282/290adv, 110lsa,.600/.600 lift),Manley custom chromoly pushrods, Harland Sharpe Roller Rockers(1.7 ratio), The springs were brand new when I installed the heads. I used Comp 914 springs with DelWest TI retainers. I installed them at 1.860" which gives me 146# on the seat and 372# over the nose. They have about 200 miles and maybe 20 passes on them. I have not revved them past 6500.



MSD Pro-Billet distributor, MSD Blaster II coil, MSD 6AL ignition box, custom 1 3/4" to 3" equal length headers, 3" exhaust with Dynomax Ultraflo mufflers, aluminum water pump, Griffin radiator.



Transmission: TH350

Modifications: ATI standard pattern, automatic valvebody and shift kit. Redneck 3000 stall converter(3800 flash off footbrake), Custom 3" steel driveshaft.



Rear end: Currie 9+, 4.11 gears, trac-lock diff



Wheel/Tire:



rear - Weld draglite 15 x 8 - 4.5 B.S. BFG 315/60 Drag Radials (30"tall)

front - Weld Draglite 15 x 4 Mickey Thompson 26 x 6 street radials



Other modifications: Global West TLC upper and lower control arms, QA1 single adjustable coilover conversion, 300#/in springs. Belltech drop springs, 3" DJM steel blocks, Lakewood S-10 Slapper bars. Summit fuel cell, -10 AN fuel line, BG fuel filter, Holley Blue Pump, Summit(Aeromotive) regulator. Custom digital dashboard, just the stock driver's seat.



I already have removed the rear seat and passenger seat. The rest of the interior is there as was as all of the stock glass and power windows/locks. Gutted the tailgate, no front fender wells. Stock power steering/alternator. manual brakes.Optima battery relocated with a plastic Moroso box. It as a 'glass rollpan



I'm doing my part to reduce my mass as well, down about 21 pounds already, looking for 45 total.



Here are the numbers on #3 cylinder(bad port) with 28" test pressure

Lift Int Exh

.100 70.1 63.6

.200 147.8 118.3

.300 211.8 140.9

.400 258.0 173.3

.500 285.0 192.8

.600 297.0 207.4

.700 308.9 220.3

.800 318.4 232.0



they also CC'd the #6 chamber at 94cc which puts me at about 9.5:1 static CR.

Yes, I know these heads are garbage, but they what I have right now.



<font size=1>[ This message was edited by: knudsonm on 2008-03-19 12:57 ]</font>

[rayL]

two things that jump out at me are the 1 3/4 headers on a big block and also the head flow at .500..im just guesstimating but with your camshaft the .550 number is what would really count. Using some RayL math i figure its flowing around 290 @.550 lift. Decent but your trying to feed a 4.250 bore with flow numbers that are more equipped for a street performance small block. Your 1/8 mile numbers look good ( torque) but the mph on the 1/4 seems low to me. I think its just running out of breathe up top. For a comparison, ive ran some 6.50 index races and turned the nitrous on 2.5 seconds out and run 6.50s @ 114 in the 1/8th. Save some money for some headers first, then heads, then intake, then cam, then ... http://www.s10v8.com/images/smilies/wtf.gif

[grimpuppy]

Can you post the entire time slip with all the incremental times. That would help determine where on the track you are falling off. I have lots of time slips in the 11.40-11.60 range. I will take a look at them when I get home tonight. I know my MPH was 117 when I was going 11.40.



I am with Ray on the heads. Them flow numbers seam pretty poor for heavily ported after market heads.



There is a guy that runs a first gen with a 454 at my track. Hyd flat tappet cam, stock open chamber oval port heads, nothing fancy. His is not near the motor you have and he runs 11.20's all day.

[knudsonm]

nevermind the retard

[jameskirk1]

What's your flowing fuel pressure under load at the top end? What's your timing set at? I can only assume you checked all the basics http://www.s10v8.com/images/smilies/icon_smile.gif

[knudsonm]

I'm dumb

[Scotty_S-15]

Sounds like you've got it all covered. 'cept maybe the converter, and the heads as you mentioned.

A couple things jump to mind:

* Sure it isn't detonating a little at the very top? Pull back the timing some as an experiment, maybe you'll be pleasantly surprised?? And jetting. Have you messed with the jetting any?

* Does it idle nice? If you can give up some idle quality, maybe try retarding the cam a couple degrees. Or, just pop in a little more cam.

[knudsonm]

Sorry to bother everyone with my stupidity.

[grimpuppy]

??? Did you figure it out?

[Scotty_S-15]

On 2008-02-06 00:04, knudsonm wrote:

Sorry to bother everyone with my stupidity.





We've all had our lapses.... or at least I have....



What did you find?

[knudsonm]

I found nothing. I am just chasing my tail with this POS. I think I need to just sell everything and start over. Science everything out for a new combo and save up the $25,000 or so I'll need to do it. It might mean I need to wait 10-15 years, but it just seems stupid of me to waste everyones time with a mis-matched combo. I don't even know why I'm trying to make a heavy barn fast.

[Scotty_S-15]

Relax Knudson! You're being a little hard on yourself, no? Take a break, clear the head, and have at it when you're up to it. No pressure.

....... And the way you're talking, you'd think you were driving a total POS, when in fact, the times you had posted were something 95% of S10 owners would kill for. http://www.s10v8.com/images/smilies/icon_wink.gif

....... Besides, I think there's a little something left in that ol' engine.

[grimpuppy]

Your combo isn't that mismatched. I think your not that bad off. For one, your 60 ft times are pretty damn good. That is usually the hardest part. I checked many of my time slips. All runs between 11.40 and 11.45 were at 118 MPH. The 1/8 times were all 7.30-7.35 and MPH was high 94 to low 95. Like Ray mentioned, looking at your MPH you are missing some HP, but you got some nice torque. With some different heads and big tube (2") headers you should be deep into the 10's.

[rayL]

a cheap way to pick up some top end would be a 2inch carb spacer.

[knudsonm]

Anyway, the engine/tranny are back in the blazer. I'd really like to build new headers so I can get my front ride height where I want it. I scienced out these 1 3/4" headers for the older oval port combo, but here are my thoughts. A 454 @ 6000 RPM is moving about 780CFM. A 350 has to turn 7800 rpm to move the same cfm and a 406 @ 6700. Are you guys that run bottom 11's/high 10's and turning your small blocks that tight, running 2" headers?



What kind of ET reductions have you guys with electric water pumps seen after switching? How about manual steering?



I hate to put everything back together and run the same numbers I did last year. I just don't have much money to put into the old girl this year.

[stroker1]

On 2008-03-18 13:23, knudsonm wrote:

Anyway, the engine/tranny are back in the blazer. I'd really like to build new headers so I can get my front ride height where I want it. I scienced out these 1 3/4" headers for the older oval port combo, but here are my thoughts. A 454 @ 6000 RPM is moving about 780CFM. A 350 has to turn 7800 rpm to move the same cfm and a 406 @ 6700. Are you guys that run bottom 11's/high 10's and turning your small blocks that tight, running 2" headers?



What kind of ET reductions have you guys with electric water pumps seen after switching? How about manual steering?



I hate to put everything back together and run the same numbers I did last year. I just don't have much money to put into the old girl this year.

My ET reductions where huge when I went to an electric water pump. Because I went to an Alan Grove alternator mount for electric water pump, and I stopped throwing the belt off, thus able to make a pass without shutting it down! http://www.s10v8.com/images/smilies/icon_biggrin.gif http://www.s10v8.com/images/smilies/icon_razz.gif



Seriously though, my headers where the most advantageous thing I have ever added to my truck. I went from 1 1/2" shorties to 2" fenderwell headers and my 1/8th times went from 7.10s to 6.80s. So about 3 tenths worth for me. BTW, I only turn the 383 to about 6200 RPMs.



And you're not the only one with small heads. I'm running Edelbrock Performer RPM heads. Comparatively speaking, you're a little worse off than mine when it comes to the heads. But maybe add a carb spacer and play with the stall and pick up some mph. You edited out your earlier posts so I don't know your whole set up, but I'm sure you can get some more top end out of it. Maybe even changing rockers might help move some power from the bottom end to the top.



I've seen 468 cid big blocks run deep into the 10's with GM casting oval ports.



Just be patient. Save a little, buy some heads. Save a little, buy some headers. It's a work in progress for most of us anyway. And that way you get to have fun while you wait!



BTW, my buddy is running a 505 BBC with a set of 1 7/8" long tubes and his camaro goes 6.00s in the 1/8th and mid 9's in the 1/4. So you can get some more out of them headers.



Stroker1 http://www.s10v8.com/images/smilies/icon_wink.gif

[knudsonm]

I updated the info on page 1.



I might try to get it put back together for a dyno day in a couple of weeks to see what it put down to the wheels. The old combo with the iron oval ports made 318hp and 376ftlb to the tires and was good for 12.80's @ 108

[knudsonm]

so which is the lesser of 2 evils?



9.5:1 CR with my current heads that flow like crap?



or



8.6:1 CR with better suited Edelbrock oval port heads

[rayL]

current setup.

[knudsonm]

Well I ended up fixed my small tube headers to get my ride height the way I want it. Now I need to modify the shock mount so I can have some suspension travel. The QA1 coilover conversion for the S-10 has alot to be desired. I think they just use the g-body parts and say it fits. The shocks bottom out before the bumpstops on the lower a-arms do.



Anybody got a plasma cutter I can borrow?