theory behind my slowness....
10-20-2002, 03:34 PM
#1
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Join Date: Nov 1999
Location: DB, FL
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theory behind my slowness....
figure I'd post it here too 
ok guys, let me start with the mods:
355sb
882 heads (9:1 cr? or around that)
edelbrock base
Slp runners
stock throtle body
24lb svo
fuel reg
TES headers/y pipe
3" pipe to flowmaster
no cat
3.23's
car is 85 iroc, with 870 ecm and hypertec 305 (yes 305) chip
now, I've tryed manythings to make it run fast to no avail, motor and (rebuilt) trans have about 40,000 on them.
best time was 14.6 at 94.7 mph with 2.1 60'
Had 3.73's, did same time
had 58mm tb, did same time (maybe 1mph slower)
try add substrac timing on dist, did the same
so far I run anywhere form 15.2 at 89 to 14.6 at 94, oh and that 14.6 was on stock TPI, slp runners and edelbrock base didn't do a thing....
my theory: I have a the peanut cam in the motor, why? because when my friend build the motor, he went to GM and asked for a TPI cam....I'd say looking at my mods I should be faster...and at the track I've seen 3 third gen doing 14.3-14.2 at 97 with stock motors (no headers and no runners upgrade). That's about the only plosible theory after everything I've tried except a compression check, since the motor isn't smoking and I've been driving the car since the engine had about 3k (when I bought the car from my friend)....I've tried everything that I can think of, and I don't belive the 305 chip is the main problem (especially on a MAF car)
any suporters of this new theory?
my next mod is going to be a ZZ4 cam....I'm not looking to be super fast, just want 13.8 and I'll go home happy
ok guys, let me start with the mods:
355sb
882 heads (9:1 cr? or around that)
edelbrock base
Slp runners
stock throtle body
24lb svo
fuel reg
TES headers/y pipe
3" pipe to flowmaster
no cat
3.23's
car is 85 iroc, with 870 ecm and hypertec 305 (yes 305) chip
now, I've tryed manythings to make it run fast to no avail, motor and (rebuilt) trans have about 40,000 on them.
best time was 14.6 at 94.7 mph with 2.1 60'
Had 3.73's, did same time
had 58mm tb, did same time (maybe 1mph slower)
try add substrac timing on dist, did the same
so far I run anywhere form 15.2 at 89 to 14.6 at 94, oh and that 14.6 was on stock TPI, slp runners and edelbrock base didn't do a thing....
my theory: I have a the peanut cam in the motor, why? because when my friend build the motor, he went to GM and asked for a TPI cam....I'd say looking at my mods I should be faster...and at the track I've seen 3 third gen doing 14.3-14.2 at 97 with stock motors (no headers and no runners upgrade). That's about the only plosible theory after everything I've tried except a compression check, since the motor isn't smoking and I've been driving the car since the engine had about 3k (when I bought the car from my friend)....I've tried everything that I can think of, and I don't belive the 305 chip is the main problem (especially on a MAF car)
any suporters of this new theory?
my next mod is going to be a ZZ4 cam....I'm not looking to be super fast, just want 13.8 and I'll go home happy
10-20-2002, 04:28 PM
#2
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Join Date: Sep 2001
Location: Scott AFB, IL
Posts: 465
I can only really commnent on a part of your post. I have never seen a stock 5.7 TPI run low 14's. They are modded no doubt. When you say a 355 SBC, then you've bored it? What about a stall? Also, what would it hurt to try a 350 chip instead of 305? They are bound to be different. What do you think? Did you do the rebuild, shop or who?
10-20-2002, 05:35 PM
#5
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Join Date: Dec 1999
Location: MD
Posts: 2,022
You've got one of the worst SBC heads ever, and the smallest V8 cam ever produced. Just a cam swap would put you in the mid-high 13's though.
The ZZ4 cam is a roller right? Is that a roller block? You might want something more aggressive than that
The ZZ4 cam is a roller right? Is that a roller block? You might want something more aggressive than that
10-20-2002, 07:23 PM
#6
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Join Date: May 2002
Location: Crestview, Fla USA
Posts: 7
As Marc said, those heads are renowed as being bad. I think a set of stock 305 or 350 TPI heads would definitely be an improvement. Keep working on it though. Nothing sweeter than a fast thirdgen.
Later,
Aaron
Later,
Aaron
10-20-2002, 09:00 PM
#8
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Join Date: Feb 1999
Location: Springfield,OH. U.S.A.
Posts: 2,947
Mine also ran low 14's "Bone Stock" 14.29 on stock Potenza's. I've always been able to hang with 4th Gen LT1's too. At least the stock to mild-modded ones.
And I've stayed side-by-side to an LS1 TA until about 75 where it "slowly" started pulling on me. (with just a muffler and K&N's)
As for you motor;
Aren't the #882 76cc chambered, that would put compression around 8.2-8.5:1, and those heads are proned to cracks. Have you had yours tested for cracks?
Most TPI 350 castings outflow the early style heads easily too. Including the Double-Humps(which I have a pair of too...). That's why I stayed with my #083's...
Swap the cam and heads, ZZ4 $180, and get a set of 350 TPI heads or SR torquer 350- heads for $374 each assembled. They are 67cc for a closer to 9.3:1 with big 2.02/1.6 valves etc....
And I've stayed side-by-side to an LS1 TA until about 75 where it "slowly" started pulling on me. (with just a muffler and K&N's)
As for you motor;
Aren't the #882 76cc chambered, that would put compression around 8.2-8.5:1, and those heads are proned to cracks. Have you had yours tested for cracks?
Most TPI 350 castings outflow the early style heads easily too. Including the Double-Humps(which I have a pair of too...). That's why I stayed with my #083's...
Swap the cam and heads, ZZ4 $180, and get a set of 350 TPI heads or SR torquer 350- heads for $374 each assembled. They are 67cc for a closer to 9.3:1 with big 2.02/1.6 valves etc....
10-20-2002, 09:31 PM
#9
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Join Date: Sep 1999
Location: MI
Posts: 2,342
hgfnhgnchg
I'd go along with this guy above my post...Some cheap but worth the price S/R World Products heads and a ZZ4 cam. Have the plenum port matchd to the runners like they should be, port the front of the plenum(bottom area), port match the base to the runners if you can...Run some kind of cold air system..
With 3.73's and STICKY tires, it should run well into the 13's with a nice program in it. I've seen a few guys with head/cam combos run an aftermarket 305 program go high 12's so....whatever works man! My old 358 TPI as run with 19lb injectors and a ADS 305 chip...ran fine..it only went low 14's but hey...it was a stock rebuild! haha Goodluck
With 3.73's and STICKY tires, it should run well into the 13's with a nice program in it. I've seen a few guys with head/cam combos run an aftermarket 305 program go high 12's so....whatever works man! My old 358 TPI as run with 19lb injectors and a ADS 305 chip...ran fine..it only went low 14's but hey...it was a stock rebuild! haha Goodluck
10-20-2002, 10:19 PM
#10
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Join Date: Sep 2002
Posts: 107
Man you guys must either have freak cars or are running on short tracks. I spent quite a bit of time at the drag strip during the late eighties and never saw a stock L98 f-bod run low 14s. High 14's at best. Now the Grand Nationals where running low 14's stock and if you ever saw a stock IROC run a Grand Nat it wasn't pretty. And almost every magazine around during that time had the same results. But of course they where only using professional drivers. But if you are hanging with LT1s, then it is a low 14. But if you look at the power curves that just doesn't make sense.
But anyways, unless you are running dome tops or something your compression is probably more like 8.2 to 1. I agree with everyone else about the heads and cam though. Those are holding you back. But a 14.6 on 882 heads is pretty darn good!
But anyways, unless you are running dome tops or something your compression is probably more like 8.2 to 1. I agree with everyone else about the heads and cam though. Those are holding you back. But a 14.6 on 882 heads is pretty darn good!
10-20-2002, 11:16 PM
#11
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Join Date: Nov 1999
Location: DB, FL
Posts: 29
ok, I've seen a site with flow numbers for 882' and a 400 lift they flowed 202cfm, more than the L98 head at the same lift. (but I do did heard that 882 sucked big time)
I actually went faster mph going back to 3.23's vs 3.73
intake modes didn't do a thing
350chip for 870 ecm aren't cheap, got to have it done custom.
far as the cam and motor, my friend had it built, so yea it's 30 over, not sure what kinda pistons went in, and for the cam went to GM and asked for the TPI cam (yea I would have gone aftermarket or at least ZZ4).
Friday I ran 14.9 at 93, had an issue with one cylinder not firering right (its a brand new prob, mostlikely cap/wire related) but no doubt the car would have gone 14.6 again at 94-95.
my options, well, my roomate got a ZZ4 cam I can get if I want to, I have an 86-89 165 ecm(and complete harness) and have a friend that could burn me a ship for it. Far as head, well those will have to do for now....can't afford that (and palying with the 69 BB at the same time).
I just want high 13 (13.8 I'll be happy, 13.5 I'll buy a round of beers ;-) )
I actually went faster mph going back to 3.23's vs 3.73
intake modes didn't do a thing
350chip for 870 ecm aren't cheap, got to have it done custom.
far as the cam and motor, my friend had it built, so yea it's 30 over, not sure what kinda pistons went in, and for the cam went to GM and asked for the TPI cam (yea I would have gone aftermarket or at least ZZ4).
Friday I ran 14.9 at 93, had an issue with one cylinder not firering right (its a brand new prob, mostlikely cap/wire related) but no doubt the car would have gone 14.6 again at 94-95.
my options, well, my roomate got a ZZ4 cam I can get if I want to, I have an 86-89 165 ecm(and complete harness) and have a friend that could burn me a ship for it. Far as head, well those will have to do for now....can't afford that (and palying with the 69 BB at the same time).
I just want high 13 (13.8 I'll be happy, 13.5 I'll buy a round of beers ;-) )
10-21-2002, 01:25 PM
#12
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Join Date: Jun 2001
Location: TX
Posts: 1,211
The 882 heads aren't as bad as everyone says they are. I ran them on a 400 in my 71 Camaro w/flat hyd cam (224, 467), stock converter, 3.42's and Radial T/A's and managed to run a 13.5 best at our local 4,100 ft altitude track. Corrects to high 12 or 13 flat at sea level.
If they didn't choke out my 400, I seriously doubt they are holding back mirage's 350.
S/R heads don't seem to make a big improvement in any of the magazine tests I've seen using them. Vortecs have and would kick up the compression over the 882's.
As for L98 times, it depends on how the vehicle is spec'd out. A T/A with all the goodies is a little porky. But something like my 89 Formula 350 twin cat is considerably lighter. I managed a 15 flat at our track with a chip/K&N and flowmaster. Low 14 at sea level.
If they didn't choke out my 400, I seriously doubt they are holding back mirage's 350.
S/R heads don't seem to make a big improvement in any of the magazine tests I've seen using them. Vortecs have and would kick up the compression over the 882's.
As for L98 times, it depends on how the vehicle is spec'd out. A T/A with all the goodies is a little porky. But something like my 89 Formula 350 twin cat is considerably lighter. I managed a 15 flat at our track with a chip/K&N and flowmaster. Low 14 at sea level.
10-21-2002, 04:28 PM
#13
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Join Date: Nov 1999
Location: DB, FL
Posts: 29
mine is power nothing and just t-tops...so it's light...no cat and no EGR stuff either.... maybe I should just built a 496BB.....
but seriously it's behond me!
also debating on doing Vortec heads, ZZ4 cam and a carb, get me better gas mileage than the 13mph intown I'm geting....hell the BB gets 10 and it makes twice the power....
unless it's a fuel pump problem...I know when you shut it off, the psi goes to 0 in about a minute or so....it did that with my 19lb injectors too...so I know it's not a bad injectors (cuz the 24 where new when I put them in...still did it)
eh what to do!! (looking up at the sky for an answer)
but seriously it's behond me!
also debating on doing Vortec heads, ZZ4 cam and a carb, get me better gas mileage than the 13mph intown I'm geting....hell the BB gets 10 and it makes twice the power....
unless it's a fuel pump problem...I know when you shut it off, the psi goes to 0 in about a minute or so....it did that with my 19lb injectors too...so I know it's not a bad injectors (cuz the 24 where new when I put them in...still did it)
eh what to do!! (looking up at the sky for an answer)
10-21-2002, 05:24 PM
#14
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Join Date: Dec 1999
Location: MD
Posts: 2,022
Originally posted by 87ROC
Man you guys must either have freak cars or are running on short tracks. I spent quite a bit of time at the drag strip during the late eighties and never saw a stock L98 f-bod run low 14s. High 14's at best. Now the Grand Nationals where running low 14's stock and if you ever saw a stock IROC run a Grand Nat it wasn't pretty. And almost every magazine around during that time had the same results. But of course they where only using professional drivers. But if you are hanging with LT1s, then it is a low 14. But if you look at the power curves that just doesn't make sense.
Man you guys must either have freak cars or are running on short tracks. I spent quite a bit of time at the drag strip during the late eighties and never saw a stock L98 f-bod run low 14s. High 14's at best. Now the Grand Nationals where running low 14's stock and if you ever saw a stock IROC run a Grand Nat it wasn't pretty. And almost every magazine around during that time had the same results. But of course they where only using professional drivers. But if you are hanging with LT1s, then it is a low 14. But if you look at the power curves that just doesn't make sense.
Mike92LX (a respected board member) had a 91/92 Formula that ran 14.3? stock. And, if you live in the mid-atlantic area, I can show you a bone stock 92 Formula that will run 14.1 all day long. An L98 in decent shape should hold up to a LT1 to 60. I've seen countless L98s with few mods pull 2.0x 60' on stock radials. After that the LT1 will start pulling do to the HP advantage.