joeblue83

iTrader: (8)

I thought my combo would dip me into the 11.40-11.50 range. All my specs are in my combo. I still have the stock airbox and maf, but I did add the ram air box below the airbox from Hawks. The next time I go racing I will have the modified airbox along with a 3.5 inch modified MAF. Does anyone have any ideas or see any problems with my combo. I do have a 3 inch cutout with was open at the time, other than that I have a 3 inch edelbrock cat back which is junk, but that should not matter

joeblue83

iTrader: (8)

last year my best time was 12.03 with a 1.59 60ft at 106 mph
And yesterday I had a 1.60 60ft 12.21 at 113
The days were almost identical with 65 degree day and no wind.

1989GTATransAm

iTrader: (3)

"I still have the stock airbox and maf,"

That is where I would start. Whoops I see you have a modified airbox.

I have heard both sides of the MAF aguement and I went with speed density. I'm in the same boat as you are in trying to get into the 11's. I'm currently at 12.12 with a TPI 355. Going to refine my tune, install a light weight starter and a little weight reduction plus better weather. I hope that allows me to get into the 11's.

Orr89RocZ

iTrader: (20)

I'd just cut the bottom of the air box out so that the filters are fully exposed. The stock air box from there on up has gone 11.4's for me so its plenty right there.

Try a bigger exhaust. I had a single 4". Do a 3.5" or 4", but i dont think its really holding you back. Maybe a tenth or so at most but who knows, maybe 2 tenths. Then again there was a guy on here, EvilCartman i think that did either a muffler swap, or full exhaust swap from 3" to 3.5" or 4" exhaust and picked up ALOT of ET/MPH.

3.5" MAF i didnt see much of a gain if anything at all. Stock 3" maf with screens cut out should flow enough for 400whp and easily go mid 11's. And a lot of tuning is required to get the car to run properly with new fabbed 3.5" MAF sensor, unless your doing something else with a translator and aftermarket 3.5".

That combo would like a bigger cam for sure but that combo should be going mid high 11's atleast.
I see you say last year you went 12.0's at 106 and this year you went 12.2 at 113. Why the big change in mph? That shows a big increase in power.

EDIT: For more questions.... What size tire are you running, where do you shift at, and what does your 1/8 miles times look like? have you had the car on a dyno at all? Who did the tuning?

joeblue83

iTrader: (8)

I have the modified airbox but just didn't have the time to put it in. When I go racing in 3 weeks I will have the new airbox put in along with a 3.5 maf also. I think thats the last restriction on my setup that I have not attended to.

skinny z

[QUOTE=joeblue83;4225484] I do have a 3 inch cutout with was open at the time, QUOTE]

I see you run Dyno Don's headers so that would be a short tube header with a y-pipe to a single exhaust. How far from the collector flange on the headers would you say the cut out is?
There could be some interesting exhaust tuning going on.

GTA matt

iTrader: (1)

With that mph you're making pretty good hp so i don't think your maf is holding you back any. What are you shifting at? Should be at least 6000 to 6200. What size tire are you running, 26 or 28? How "good" is your tune? You seem to be missing something in the midrange. Whats your 8th mile et and speed? Should be about an 8.75 @88. Your turning the same mph as me but over 2 tenths slower and mine has only run in crappy summer air.

I did two back to back runs a few weeks ago, one with the intake on and the other open throttle body. went 12.019 and 12.018, so the air intakes not really restrictive. With a cutout your exhaust shouldn't be holding you back either.

305sbc

iTrader: (3)

A miniram + automatic is more sensitive to tuning in the low & mid range RPM since the shift recovery is still very low. I would concentrate very much on the tune.
What RPM are you shifting at? Where's your peak HP at? and are you locking the torque converter during your run?

joeblue83

iTrader: (8)

I had my car dynod a few years back and my max horsepower was at 5800. So thats where I shift it. My timeslip from saturday looked like this
60 ft 1.605
330 5.042
1/8 7.831at 88.46
1000 10.212
1/4 12.20 at 112.96
I did cut out the plastic under the airfilters and I also have the air boxes under them. The cutout is right after the tubes meet, which is right behind the front right tire. I am running MT ET streets 255/50/16's in back and weld pro star 15's in front

GTA matt

iTrader: (1)

You need to shift it at a higher rpm. I bet that you have a very flat hp curve up top, and even if it peaks at 5800, it probably is still making good power to 6300 or so. shift it at 6000 and see what happens. I also bet that your motor kinda bogs down on the 2-3 shift. I raised my shift points and just can't seem to get rid of it. Its because of the big gear ratio spread between 2nd and 3rd.

I picked up 3 tenths raising my shift point from 5700 to 6000.

Big Dog Chevy

You are making good top end hp but it's the low to midrange power that is holding you back from 11s. What's your race weight? You went from 12.0 @106 to 12.2 @113 with the same 60ft? How is you trans, is it slipping on the shifts or your TC. I agree with the guys you should shift a lil higher. You should be running 11s with your combo now.

joeblue83

iTrader: (8)

my raceweight is 3550, I will try and shift at 6000 instead of 5700. And when I shift it into 2-3 it does feel kind of like a bog. I was told by someone that there is no need to go above 6000 with a roller cam small block. I will check my old dyno sheet and see the hp curve around 6000 and will keep everyone updated. My tranny and torque converter are working perfectly

Big Dog Chevy

You'll fing best shift rpm about 300-500rpm past peak hp rpm. 5700-5800 peak = 6000-6200 shift. What are your dyno numbers and rpm peaks for hp/trq.

Orr89RocZ

iTrader: (20)

If you dont want to go fast, then keep it below 6K haha. I shifted my car between 6500 and 6800 and i made peak at 6300. Hp was so flat after that, 6500 was about same as 6300 so i could get away with 6600+ shifts

I'd give your car 6000-6200 definately. 6200 seems optimal as i bet hp is still pretty flat to 6K.

With 3500 stall and 3.90 gears you shouldnt be feeling too much of a bog on the 2-3 shift unless thats your converter locking up. Check your bin file for TCC lockup threshold and raise it to 120mph so the converter stays open during the whole 1/4 mile run. My car always ran faster that way.

Your picking up good mph after the 1/8 but i still think that combo could be capable of 115mph and that would indicate more hp than what your making now.

Post your dyno sheet if you still have it.

1bad91Z

iTrader: (1)

I've seen people run 11.9 at only 111 mph. He "should" have hit an 11.9xx with what he has now.

Try the high-flow lid with the stock "de-screened" MAF, shift a couple hundred RPM's higher, and make a few passes like that and see what happens.

If that doesn't do the trick, look into the PROM, you may need more fuel to go along with the extra air. If you don't have the means to re-burn a .bin at the track, give it one pound more fuel pressure.

Orr89RocZ

iTrader: (20)

yeah but those are usually setups with high drag-race efficiency. Well tuned suspensions and gearing, and thus can run great ET for the power. 700r4 trannys arent the optimal choice for that, but I do agree he has 11's in that combo

joeblue83

iTrader: (8)

Here is a scan of the dyno run. Its on an engine dyno and not RWHP

NatesZ/28

Id think about moving some weight around, shifting like a man, maybe play with some tire pressure. A good tip would be to have someone vid a couple passes from behind the car. Welcome to REAL dragracing...throwing more power at the problem wont help. You HAVE enough power, now tune it. I hope you have a log book, if you dont...you're missing a BIG tool

Keep track of your tire psi (front/rear) Air Temp, Shift RPM, RPM when you cross the stripe, Weight,suspension settings and everything on your timeslip as well...and leave space for comments you can make from run to run (spun too much, sleeping on the line, got out of groove) Pretty quickly you'll see a few tendencies emerge...

Never EVER change more than 1 thing at a time either...its bad karma.

You probably wont hit a home run...you have to sneak up on those kind of numbers in small increments.

I dont usually run ET Streets, we use Nittos...do tyou really burn them or more of a dry hop?

Orr89RocZ

iTrader: (20)

nice hp curve! that thing doesnt really drop off til after 6500. Shift at 6300-6500!!!! You'll get your 11's and probly gain a mph or 2

skinny z

What kind of headers were you using on the dyno?

Big Dog Chevy

I agree with orr on this, you are leaving a lot on the table by shifting at 5700-5800 rpm. Shift that thing at 6300-6500 at bust into the 11s before I tell on you

joeblue83

iTrader: (8)

I will shift at 6300 next time. As for the tire and pressure, I have found that having them at 20 psi in the rears works perfect. They hook great, no problems there.

Red89C4

My buddies combo of .... Stock CID, OEM 113 Alum heads ported by TPIS, Mini Ram, Hooker headers into Flowmasters, 3.73 rear, 4000 stall converter & TPIS ZZ09 cam, has gone 11.23@121 in a 1989 Corvette. I'm surprised yours has not run faster then it has.

Big Dog Chevy

That's a good time. That vette must weigh 2900lbs.

joeblue83

iTrader: (8)

does he has the 700r4 and that a hell of a stall for a street car. Good times though

Big Dog Chevy

Joe, when is the next track date for ya, and what track do you run at.

Red89C4

Actually our cars weigh about 3400 lbs +/- 50 lbs depending on the amount of fuel we run.

I also forgot to mention he has the TPIS computer chip for his combo, and he drives the car to and from the track for each event (about 75 miles one way).

Red89C4

Actually with the 383 & 3500 stall "joeblue83" has, his stall should be very similar because his torque is higher.

1989GTATransAm

iTrader: (3)

I agree with the above posters. You are shifting way to soon to get the most hp under the curve. That alone will probably get you into the 11's.

Also I think your motor is running out of air. Peak torque is around 4900 but peak horspower is around 5800. Usually on a good breathing motor there should be around a 1500rpm gap. IMHO your peak hp should be in the lower 6000 range. Again IMHO this is supported by the flat lining of your hp.

joeblue83

iTrader: (8)

hopefully the modified airbox and maf will allow much more air into the engine. I race at eith Byron Illinois or Earlville IA. I will be racing at Earlville August 15th. Hopefully enough time to get the custom maf made.

Orr89RocZ

iTrader: (20)

what size throttle body do you have?

joeblue83

iTrader: (8)

52mm

Orr89RocZ

iTrader: (20)

Not sure if it would make a difference, but a 58 may help alittle.

joeblue83

iTrader: (8)

a 52 flows 900 cfm, that should be enough for my application. A 58 flows 1100 may be too much. The old equation that I was taught, is that every horsepower needs 1.5 cfm to flow. That may be wrong but that is just what I heard

1989GTATransAm

iTrader: (3)

"a 52 flows 900 cfm,"

It is the accumulated losses that you have to take into account. With everything hooked up your total available cfm will be less than the part with the most restiction.

With the MAF you may be right. However as you open things up a 58mm may be in order. What you need is a method to determine your manifold pressure at wide open throttle. It should be very close to atmospheric. With Speed Density we use the map sensor and that is converted to KPA which makes it very easy to determine if there is a restiction.

joeblue83

iTrader: (8)

I don't think going from a 52 to 58 mm will be worth the 300 dollar difference. I have bigger problems that need to be fixed first

Big Dog Chevy

That's true, I would get that motor right first then tuned on a dyno then up the shift rpms. You may hit your goal with what you have. If not then spend more money or hit it with the JUICE!

Orr89RocZ

iTrader: (20)

I got a holley 58 that i was hanging onto, i may beable to sell it off for much less than 300

joeblue83

iTrader: (8)

throw me some pics and a price

Orr89RocZ

iTrader: (20)

I'll get some for you, i was gonna wait to sell my whole HSR setup with that TB but parting it all out will probly be better and quicker

Viprklr

iTrader: (5)

Hey Joeblue
Let me know the next time you plan on heading out to Byron. I'll see about meeting you there.

joeblue83

iTrader: (8)

i am going to try and go in september and then once in october, if I can get off of work that is.

joeblue83

iTrader: (8)

I was just messing around with the throttle body today and found out, that it's not open all the way. It has about 30 degrees left to rotate before its wide open. I am going to fix that along with shift at 6200 and just finished up with the 3.5 maf along with the 4 inch custom air box. This should definately put me down into the 11.70-11.80 range. I hope
I am racing this saturday in Iowa and the weather seems to be sunny and low 80's, I will keep everyone posted on my results from the day

Big Dog Chevy

There you go. 11s here you come!

Orr89RocZ

iTrader: (20)

HAHA 3/4 throttle racing at its finest. Go get your 11's. I'd try fixing the TB full throttle problem first, try that and then do the large MAF setup to see how much of a difference each step makes

joeblue83

iTrader: (8)

I will only have enough time to put the bigger air box on before I race. I will leave the throttle like it is, and use the stock maf that is already on there. Time is not on my side. I guess I work to much. Well we will see how much of a difference it makes shifting at 6200 and using the bigger air box. Hopefully its high 11's

1bad91Z

iTrader: (1)

If you dont fix the throttle body issue first, right there is a bottle neck that negates putting on the larger air-lid and MAF. It also puts your TPS % lower than it needs to be in order to utilize your upper Fuel and timing table parameters in the PROM.

Make a pass with the throttle body fixed and the larger air-box only first. Then try the larger MAF to further reduce the restrictions.

joeblue83

iTrader: (8)

I didn't have enough time to fix the throttle body and do the 3.5 maf. But I did raise the shift point to 6200 along with the bigger air box and picked up 6 mph. here are a couple of the time slips. I think my mph is very high for the time I am running. The first pass of the day I put it sideways out of the hole but still managed a 117 mph. I thought I would get the 11 second time slip sometime that day, but just didn't happen. I will fix my throttle body and the maf before I go out the next time, which will be sometime in October.

Big Dog Chevy

Damn almost! Just fix the TB and u r there! 3.5" maf is going help a lil.

1989GTATransAm

iTrader: (3)

I agree. With that mph you should be there.