cas0484

Well, guys, Disappointment seems to be my thing. I went to the track last night for the first time. And boy was I disappointed. I expected to run alot better. It really seems like the car launches nicely then falls flat on its face. I just dunno what to do anymore. Here are my runs:

1st run
R/T .655 .
60' 2.196
330 6.517
1/8 10.107
mph 68.52

2nd
.947
2.203
6.453
9.989
69.49

3rd
.876
2.222
6.506
10.076
68.82

4th
.876
2.278
6.562
10.121
69.24

On my last run I ran against a bone stock 92 Rs 305tbi camaro and he ran a 10.5 to my 10.1 I just don't understand why I'm running to slow. My 0-60 is awesome and my 60' isnt too bad. My friends watching said the car takes off really fast and then seems to die. I'm about ready to give up. I have the holley tbi waiting on a intake manifold but I'm sure that won't help me that much. I just dont understand what the problem is. And these times are after my gear/posi swap. Any ideas? I'm about ready to give up

ShiftyCapone

iTrader: (7)

Well judgin by your sig you should be faster. What heads and cam are in that motor? Are you using the stock fuel pump? If you are running stocker heads and cam that is one of your problems. Another would be a poor tune. You are going to need a custom tune to dial your set-up. A cop car chip will really only get your car close if that motor has stock top end.

cas0484

I'm assuming the heads and cam are crap and the motor is probably a Lo5. It was supposed to be a l98 but I guess I got screwed. Even with the crappy heads and cam I would expect it to be faster than that. It has absolutly no top end at all. The computer chip is the generic cop car chip. So I'm sure that doesnt help either. Also, the fuel pump was replaced in October with the TPI pump.

steve8586iroc

Looks like it's time do do the datalogging thing and see whats going on with the stock tune. Have you do the ult. tbi mods yet? It might not help you now but it would help when you get the tune right.

Steve

ShiftyCapone

iTrader: (7)

The basic LO5 even when fully tuned is only margoanlly faster than a similarly equipped LO3. That is why you have no top end. Data logging and chip burning is where I would start.

IROCaholic

Man, I was hoping that everything was going good with your setup now. That sux that your still not running the times you want. I dont know what is wrong with the car, but I can tell you that your 60' foot is pretty good and your reaction time could be a little better. How are you launching? have you tried shifting at different RPMs manually. I know that when I first started running my car when I had the 350 tbi I was getting terrible times until I started hitting the right shift points(my tach was way off). I would try doing different things each time you run to see if you get any improvement in your times. Good Luck.

cas0484

Since it was my first time I just left it in Drive and had at it. I was launching by bringing the rpm's up as much as i could before the tires would start spinning and then giving it as much gas as possible without stopping. Either the intake/tbi is choking it, I'm in some desperate need of tuning or quite possibly my motor just plain sucks. It's just so disappointing to barely beat a bone stock lo3. I hope all my time and money hasn't been wasted.

IROCaholic

Dude leaving it in drive is probably killing your times pretty bad. Your car is probably shifting at like 4500 rpms. Try to manually shift and play with different shift points to see what RPMs your car likes best.

njspder

i think you are also only lookin at the end of the slip to determine how good/bad your run is. you have to read teh whole slip to really see what is going on, adn like any good book, you start with teh first chaptor, 60ft times.
with your mods your car shoudl be easily capable of cutting a 2.0ish short time. are you spinning? is teh car bogging a bit? these are the questions you need to answer first. also, how are you staging the car. teh 60ft tiems are rather inconsistant. next tiem you go to teh track, take yoru time to get teh caqr into teh beams.
pull up slowly until you turn on teh top lights(teh prestage beam) and come to a complete stop. now, back you foot off the brake jsut enough to hold the car still and sort of rock it forward by pumping the brake peddle with short little bursts of brake. this will let teh car inch forward, like you see teh serious bracket racign guys do, as soon as teh second set of beams(full stage) comes on stop. this will put your car "shallow" in teh lights and give you teh greatest roll out(think of it as an 8inch head start) before the timers start.
once you have your short times consistant you will be able to more clearly test what teh car wants at launch and benefit from it.
i do agree with teh others that you shoudl try to shift your car on your own, i usually got my best results shifting around 5000rpm since the 1 to 2 gear split is so bad on our cars.

good luck

later
tim

cas0484

Thanks for the advice. When you say manually shift it, do you mean dropping it in 1st and then shifting into 2nd and then into drive or just leaving it in 2nd and shifting up? I'm kinda scared to manually shift cause I've heard it's bad for the tranny and my tach is so off I really dunno what rpm's I'd be shifting at.

IROCaholic

Put in first and shift from first to second and from second to drive. Its not bad for the car I dont know why everyone says that. Your just telling the car when to shift instead of letting it shift on its own. If your tach is off get an aftermarket one because its pretty important to know when your shifting. Your shift points alone could be the reason you dont have a very good time. Start there and if you still have bad times then its something wrong with your setup. I think you just need to get a better feel for the car and a little more practice and you should be putting down some decent times.

dimented24x7

iTrader: (2)

Hey NJ, long time, no post



There are alot of things that are working against your car. The small stock tbi will be a bit restrictive. Same thing for the intake. The tune on the ecm is probably less then perfect as well. There is also the stock torque converter. It has a really low stall speed and if it stalls outside of the motors powerband, itll bog down pretty good and slow down the car. You could check to see what motor you have. Pull one of the valve covers and get the casting # of the head. Run it by an online database and see what heads are on the motor. It wouldnt be surprising if the L05 was used as a replacement engine. Lasty, you probably will also have to start tuning your EFI. Unlike a carb, a SD ecm only knows as much as you tell it and no more. It really has no idea how much air is really flowing into the motor or how much fuel to really add, or how much timing the motor should get.

cas0484

Thanks for all the help everyone. As far as chip tuning goes, I have read up on the diy-efi articles and it all seems greek to me. I also don't have the equipment to do it myself. I know how much I can benefit it from it but I really dunno if that is my problem. I really need to datalog, but unfortunatly the day my aldl cable came in was the day my laptop crapped out on me and I have no access to a laptop to do it now. So i'm really in the dark here. I was also thinking a stall converter would help, I noticed when I powerbrake it up it doesnt take very long for the car to want to leap forward, I'm assuming the stall is ridiculously low. I just don't understand how this car can leap up to 60 like its nothing and then fall flat on its face. I only ran 3mph faster than a bone stock lo3. And I mean bone stock, the guy only had a k&n(and not an open element). I'm just getting tired of dumping money into this thing only to yield little to no results. I'm doing my best to remain optimistic but my patience is wearing thin. Thanks for all the help and keep the ideas coming!

dimented24x7

iTrader: (2)

If you have an L98 longblock, then all you really need is an intake and the larger tbi to be in buisness. While the L98 cams care conservative, theyre non the less decent and will do what you want. Without tuning, though, even the best motor will run like poop. How does it behave? Does the motor have decent low end and then jsut lean over up top? Does it pull good through the low gears but taper off when under load in the higher gears?

cas0484

I'm sure some datalogging could really help in finding out what the problem is. But all I know is that the car has incredible low end torque, from a stop or a slow roll it pulls really hard but at about 60 it just dies. I do have an air/fuel ratio gauge and I know the narrowband isnt very accurate but at wot it is almost off the gauge rich. However, black smoke doesn't come out of the exhaust nor are the plugs fouled. I really need to datalog. But low 10's and a best of 9.9 isnt gonna cut it. It was almost embarrasing to run against that other RS.

BronYrAur

iTrader: (1)

You definitely need to do some datalogs and post BLM tables on here and all the information and we should be able to tell you what's wrong.

vwdave

I am willing to bet money its your tune. Mine did the SAME EXACT THING. I just didnt feel justified buying the equipment to do the tuning, so I bought a TPI....and now I have to buy the equipment anyways.

https://www.thirdgen.org/techbb2/sho...hreadid=204140

cas0484

Thanks for all the help and input. Everyone on these boards rocks! Anyhow, I'm going back to the track this thursday for round two. I'm gonna try manually shifting this time and play around with a few things. I'll post what times I run this time. I'm trying to get hold of a laptop so I can post some datalogs on here. Something just isnt going right with my car and I wanna know what and fix it. Thanks for all the help. I'll post the times on thursday.

406-IROC

...."stock tbi with vafpr and 65pph injectors"

Restriction, restriction, restriction. Of course you'll launch hard, but you're dying at top end. Even with a good tune, you're not going to run the numbers you want.... that is of course until you install the Holley TBI and newer intake.

Everything you did (which are excellent mods), is still pending.... cuz what good are those mods, without the right amount of incoming air. Mods like those will only slow you down with the stock TBI and intake....

Give you're ignition a once over as well, cuz with a weak coil/spark.... torque can only take you so far.

cas0484

Ok everyone, I went to the track again last night and ran a little bit better. I did nothing to the car, it was exactly the same as the last time I ran. This time around I manually shifted the car and worked on my launches etc.... I still think I should be running a little bit faster than I am but I'm almost postivie the TBI/intake/chip are holding me back. Here are my new times:


R/T .694
60' 2.152
330 6.434
1/8 9.981
MPH 69.49


2nd
.584
2.135
6.326
9.884
69.72

3rd
.367(red light)
2.129
6.288
9.756
70.93

4th
.715
2.169
6.302
9.752
71.00

5th
.646
2.130
6.293
9.776
70.52

89305RS

hmmm heres what my L03 ran last saturday.

R/T -.063
60' 2.322
330 6.579
1/8 10.105
mph 70.13
1000' 13.20
1/4 15.675
mph 87064
My 1/8th mile is a little slower than yours but i have a stock chip with an LT-1 cam. BUT my MPH is faster than your first night runs.

buzz12586

Man thats really flying!!!

89305RS

sorry 87.64 mph

kdrolt

9.7 @ 71 mph in the eighth mile works out to around 15.0 @ 89 mph for a quarter mile. An 9C1-version of the LO5 (i.e. police Caprice engine, with the bone stock spec 205 fwhp for 92-93) will run low 16s in a 4100 lb Caprice with 3.42 rear. In a car that's 500 lbs less weight, I'd expect 0.6 to 0.8 sec quicker, so it would run in the 15.4 to 15.6 sec range. So it looks like your mods are giving you roughly 0.5 sec improvement.

Do you know for sure what cam is in that engine? The roller cam Lo5s had either the "peanut" cam from the L03 or the L98 cam (only when used in the 9C1). The difference between them is 180 fwhp vs 205 fwhp, with the non-police L05 using the 55 #/hr injectors and the police model using 65 #.hr, in otherwise identical engines. So the cam does matter a lot.

Since you mention adding an new intake manifold later, then you probably still have the GM stock intake, which is definitely not helping you.

I also wonder if you have checked the fuel pressure at idle, at steady cruise, and at WOT ? Your engine needs stock fuel delivery at idle, slightly more fuel at cruise, and a lot more than stock at WOT ---- but it looks like you have no idea how much is getting to the engine. If you are using the vFPR in the bone stock configuration (i.e. using the spring that came with it) then you are probably running to rich at WOT.

CamaroMike

Am I the only one that sees a problem here! TPI pressures are like 50-60PSI! TBI is 15-20PSI. I hope TPI was a typo.

BronYrAur

iTrader: (1)

A lot of guys use a TPI pump because the TBI one sucks and can't even hold 15 psi under load most times. The fuel pressure regulator on our TBI's will easily keep the pressure within spec using a TPI pump.

CamaroMike

Chevy's ZZ4 thirdgen conversion kit uses the TBI pump to support 308HP and states there is room to spare! :lala: Don't see why there would be a problem using a TBI pump. If your theory held true then people would use a TPI pump for carb setups. Not saying you can't use a TPI pump in the TBI application, just don't think the regulator was ever designed for those volume levels. :werd:

IROCaholic

They use the tpi pump because once you get into heads,cam, etc you need more pressure. Fuel injection needs alot more pressure to function then carbs do. It worked with the ZZ4 because they only needed like 6 psi for the carb.You wouldnt want the TPI pump for a carb application because Carbs dont need that much pressure.Therefore the TBI pump is perfect for a carb as long as you have the bypass style regulator for it.

CamaroMike

What I am saying is that if the TBI regulator can cut TPI pumps fuel pressures by 35-40 PSI then why can't a carb regualtor cut the TPI pump 45-50PSI. It can't. Then how can a TBI setup use a TPI pump and control the pressure consistently. The higher pressures that vary on TBI setups with TPI pumps might really screw with the calmap in the PROM, through erroneous O2 readings.

If you really want more pressure get a high performance TBI pump and an adj. pressure regulator from TPIS.

BronYrAur

iTrader: (1)

Our fuel pressure regulator can be made adjustable. The regulator has a return line that will control the fuel pressure no matter how much is put into it. A lot of guys on here have used Walbro 255 pumps, which is even higher volume and pressure than the TPI.

The TBI pump is just fine for a stock motor but they tend to die easily on old cars such as our thirdgens. As long as the regulator is functioning well and with good return lines it will hold whatever pressure you set the spring height at. The reason people switch to a TPI pump is that if you have a heads and cammed 350 with TBI you may want pressure as high as 28psi (referencing Jon Prevost's 350 HO setup). A TBI pump would never be able to hold that kind of pressure.

CamaroMike

Learn something new every day!

cas0484

The motor is the police one. It said it was on the order sheet for it. I don't have the vafpr on there anymore. I just have the stock regulator on it with the 65pph injectors in the stock tbi. At idle it stays at 13psi so I know that tpi pump isn't causing any problems. What do you think? Should I be running any faster or is this about right?

vwdave

cas, get the numbers off the heads. I still think you got a L98, but the FI is not tuned for the different airflow charactoristics the L98 heads have that are different than the L05 heads.

BronYrAur

iTrader: (1)

If it says its 9C1 LO5 on the order sheet, then your times are about right. I'm not too familiar with 1/8 mi runs but you have a 15.0 at 97mph in your sig and that sounds about what that engine should run. All it is is an LO5 with an L98 cam: the heads are holding you back.

But, you definitely need some chip tuning because after the headers and full exhaust, Holley 670, and performer intake your fueling is probably way off by now. I would look into getting a laptop and doing some datalogs and post them here. We can let you know exactly what it needs then, but I wouldn't worry too much you're not too far off from what that engine should run. You need some real cylinder heads.