Question: C4 tune up

[warren s]

Fluke 77 Multimeter - eBay (item 180590694491 end time Nov-28-10 13:21:01 PST)

Thats a link to the model that I have. It worked great for over 20 years.
There are 100 of different ones around, Radio Shack has a dozens.

I do lots of electrical work, both on Corvettes and in my home. Its a great tool.

 

[bartric]

Alright, I believe my dad has one of those around here some where. Now how exactly do I use that to tune my car?

 

[Schrade]

A multimeter, in this day and age, is a necessity for FAR more than just your car.

But to answer the question, here's a scenario which is repeated I'm SURE, THOUSANDS OF TIMES, EVERY DAY, in this country.

You have an SES light. You go to the mechanic, he plugs in, and reads DTC34, for example - MAF CIRCUIT fault. He comes to you and says, "It's a DTC34, which is MAF circuit. It's probably the MAF sensor, and I can replace that, and have you on your way."

You pay him $220 for the part, $55 labor for an hour (while it took 10 minutes to change), and hit the road. You don't get to closed loop for a week, and then the SES is on again. You go back, and repeat the process. You get a replaced MAF no charge, your MAF goes on the shelf for the next guy who also doesn't have the FLUKE Multimeter. You pay another $55 labor tho'.

WHEREAS...

If you had the Fluke MM, and the information from the mechanic about DTC34 MAF CIRCUIT, you would have gone home, checked the FSM for the proper voltage that feeds the MAF SENSOR, on 'X' wire, found out that there's no voltage because of a chafed wire (or there IS voltage, but the 'Y' wire is not grounding out the circuit), and you'd have re-connected it, and spent $0.00.

But we sheep (myself included) are stupid, and lazy, and we're broke because of it.

 

[bartric]

Okay, I've uploaded a video on YouTube of the car running, the audio is definitely not the best, but if you listen well toward the end you can hear it starting the 'almost die, rev, repeat' sequence until I turn it off.

YouTube - 1984 Corvette running problems.

And yes, I agree, us sheep do tend to be too lazy to find it ourselves, but I still think it may be the timing, because when we finally got it to hold a somewhat okay idle, my dad said it was reading 40 degree BTDC. And it's supposed to be 6.

 

[Marv02]

Thanks boomdriver LOL

If you want a real taste, look up threads in here from Marv...he just built a motor with a HP goal on a budget. He will tell you first hand it ain;t cheap as it started to be. And he did not add turbos, either.

QUOTE]


Thanks boomdriver LOL

I think I have $4500.00 in to the motor and $1000.00 in the trans alone so far plus all the headachs doing the swap over.

Like other have said HP cost money I knew this going into my project injectors (200.00), Chip (150.00), Trans build up, Higher flow intake with runners (1000.00), set of good heads (1000.00) and a cam (150.00), R/R arms $200.00I, It not a race car and never was built to be one, Plus bottom end This up to you cast or forge stroker or not use the old 2 bolt main block + machining work to make it right.
I went with a cast 4 bolt main motor so if I wanted to up the HP latter it can handle it (1300.00) gaskets oil coolers stuff add up fast $500.00.

I read where other have used uesd parts but I didn't want to go that route I read others have built a 383 for what I have in to my 357.

But that what others have said I know what my project has cost me with mostly all new parts.

I pushing Using a online dyno 340 to 360 HP and 427 Tq Numbers with 307 rearend.

Just build you'r self a bullet proff SBC and call it good Tubo Nice Supercharging nice but Why if going to be a street car and you dont want to be tuning it every time before youy go drive it.

I had a street bike that way it was so built you had to tune it jall the time took all the fun out of it Plus race gas.

I can run reg pump gas get 25 to 30 MPG all day long still have great power for a 3200 Lb car.

Use the money for other things I painted the car my self in my garage Cost for all paints and stuff $400.00.

New seat covers $1000.00 new windsheild $125.00 had the rear window retinted .

Now I saving to rebuild the rearend and big Brake kit plus some cool wheels and wider tires.

I know the car most likey wont be worth as much money I sticking in to the car but I going to give to my Daughter so when she my age it might be worth some money by then she 8 I am 46 yeras old.

 

[Marv02]

I much rather have a street car with low and midrange type power gets off the line quick when you stand on it at hwy speeds around 2000 RPM's this where my motor is set up to run in it sweet spot it shit and get and still get great MPG Been able to pass that slow driver is sure nice.

But If you want a 200 MPH + super soinc type car go right a head it you life and the poor family you mite end up killing comming the other way at those speeds thing get ugly too fast and most of the time you not going to live thought the high speed crashes.

You mite think your a great driver but at 200 MPH+ it happens so fast you just there for the ride.


A lot of newer car claim 300 HP but you have to wind it up to get to it when the TQ of the vett is pulling away from them trying to stay up with you sure they mite have more up on top than you do but who cares.

 

[bartric]

Well, I never said I wanted a 200+ mph car, I even said in one part, that I would rather gear the transmission so that it wouldn't get over 120-140. I've seen 120, and it's quite thrilling but I have no need to really get over 140. And on that note, there isn't a REAL reason to get going that fast in the first place.

As far as my driving experience goes, I'm only 19, so it's whatever I've acquired in the past 3 years, first time I actually drove was when I was 10 my dad let me drive from my house to town, about 5 miles. I don't just street race people in big straight lines, most of my high speed experience has come from slaloming down the road from town to my house as fast as I can. Which will more than likely stop when I get my Corvette going. My slalom is down a quite curvy backroad that's about 5 miles in length, speed limit is 45 and take about 7 minutes to drive. I can generally make it in about 3.5-4 minutes in the Camaro I use to drive and the Acura that I now drive.

I'm really wanting the Corvette to be a street car with amazing acceleration but right now, I just want it running and drivable, then I'll work on how I want it to be, I don't plan on dumping too much money into power though, a lot is going to be going to making it look nice, so I might aim for about 250 hp now.

 

[Schrade]

'almost die, rev, repeat' sequence until I turn it off.

That was all you had to say... loping idle.

Follow this procedure to the letter.

Originally Posted by Schrade
No one got the proper technique for vacuum leak detection... :confused

FIRST (fully warmed up motor); block the pedal, or block the throttle linkage. YOU HAVE TO DO THIS TO GET A STEADY IDLE , around 1,250 rpms, or a little higher. If you don't, you can fish starting fluid, a propane hose, or WD40, or Krylon, or hair spray, or pee, anything, until you need a sweater in Hades, but if the motor is lopin' already from a vacuum leak, you ain't gonna' find any vacuum leak, unless it's so big that Little Jack Horner can stick his thumb in it and pull out a pineapple NOPE.

AFTER you get a steady idle, THEN, you can spray starting fluid everywhere - that's the best detector, because it's vapor pressure is very high - a LITTLE at a time, until you get the SURGE. Follow the vacuum lines to the EVAP cannister too. You might even have to follow the EVAP lines from the EVAP cannister to the gas tank too, but that vac leak will show up as a DTC 32 EGR fault, and won't normally show as loping idle, unless the EVAP cannister has been by-passed (been there, saw that uh-huh).

If you get a surge in a tight spot, and can't tell exactly where it is, light a book of matches, blow out the match heads while they're still burnin', and feed the smoke to the tight spot.

Fear not the starting fluid; you cannot put the can down fast enough and light the matches fast enough to catch the starting fluid, because the vapor pressure is so high.

Bookmark this post YUP.

 

[bartric]

We tried that yesterday because the seal between the intake and the cfi is a little iffy, and on the passenger side it would pick up a bit, but the idiot that was spraying it got a little too happy and some how ended up setting my engine on fire... nothing was harmed, got a fire extinguisher and I've got the engine cleaned back off as noticed by the video (or cleaned all the white powder off at least).

 

[Marv02]

If I recall there a web site the is just for crossfire injection.


Sorry about the 200+ MPH thing I so use to hearing young drives that want the fastest car around that can do super sonic speeds.

If I was you #1 how many mile on the engine if low on miles think about finding some used better flowing heads put a high lift longer duration cam in the car.

These cars back in there days were detuned because of smog back then they didn't know how to make power and get to past smog at the same time.

If you don't have the stupid smog laws to deal with like we do out here in CA pull the cros fire off put a chepper manifold and carb pull the cats let the car breath even with the stock exhaust.

I think with 250 HP you can use the stock trans set up I read it should be good up to 270- 280 HP or so TQ and heat kills trany's.

Or find someone like me that still has there stock motor sitting inback of there garage they wat get rid of Cheep it 230 HP 330 TQ with intake runner oil pan flex plate water pump Hint Hint ready to run with nothing wrong with it.

$230.00 plus you arange and pay for shipping around $150.00.

Well, I never said I wanted a 200+ mph car, I even said in one part, that I would rather gear the transmission so that it wouldn't get over 120-140. I've seen 120, and it's quite thrilling but I have no need to really get over 140. And on that note, there isn't a REAL reason to get going that fast in the first place.

As far as my driving experience goes, I'm only 19, so it's whatever I've acquired in the past 3 years, first time I actually drove was when I was 10 my dad let me drive from my house to town, about 5 miles. I don't just street race people in big straight lines, most of my high speed experience has come from slaloming down the road from town to my house as fast as I can. Which will more than likely stop when I get my Corvette going. My slalom is down a quite curvy backroad that's about 5 miles in length, speed limit is 45 and take about 7 minutes to drive. I can generally make it in about 3.5-4 minutes in the Camaro I use to drive and the Acura that I now drive.

I'm really wanting the Corvette to be a street car with amazing acceleration but right now, I just want it running and drivable, then I'll work on how I want it to be, I don't plan on dumping too much money into power though, a lot is going to be going to making it look nice, so I might aim for about 250 hp now.

 

[Schrade]

That's why you spray a little at a time - note the bold font.

It has to be done right, AFTER you check static timing, and compression. The only way the stuff will ignite, is if the valve is not seated on squeeze/fire, or if timing is so far off (less likely, with electronic timing).

Do you know static timing check? Got a compression gauge?

 

[Marv02]

Just word of someone done this do it outside my car was on fire when I found out the hard way I had a bare wire on one of the injectors when the carb cleaner spray hit the wire it was on fire in the garage running by my self on the right hand side of the car.

With no one there to turn off the car I got lucky I end up blowing fire out.

I was also told before spraying the running engine start the engine when it dark outside so if there a open spark you can see it before you endup with a fire like I did.

 

[bartric]

Marv, I know what you mean, honestly in my mind I use to want an extremely fast car capable of 200, but after I thought about it a bit, I'd much rather have a 10 sec 1/4 mile car that tops at 120 or 140, just sounds smarter, plus, if I set my gearing ratios closer together like that, then it should actually help my mpg a little as I can keep my rpm's lower by shifting more often. However, that's not my expectations for this car (anymore, haha).

I used a program I found on the internet, just to see what it said my car would do as far as drag timings, and, I was fairly happy with the results whether or not they are going to be very true.

It said with 205 flywheel hp (which I assume the hp rating on it was flywheel) for a 3300 lb car (I guessed at the weight) that it should be:
1/8: 9.91 sec @ 69.7 mph
1/4: 15.46 sec @ 87.1 mph

I know those aren't fantastic times, and I'm sure my '01 Chevrolet Cavalier might be able to pull out better times, but it's what I expected. And it at least gives me a starting point.

If I did decide to change the transmission to be able to withstand a beating of 300 hp, should I find another automatic, or should I change it to manual. (I love manual to death but I don't know if I want to go through all those changes and cutting holes and junk)

If so, what transmission should I get?

Again, I'm not shooting for 300 hp, but I just want to make sure it'll withstand any amount of stress I put on it

 

[Marv02]

With my 340 to 360 HP it showing mid 13"s so if you want 10's you looking at some big bucks to get that fast.

If I remeber correctly you have a 4 speed man in the car I had that set up in my old 1982 TA but it had a carb I use to beat on that car blew the rearend but the trans held up, lot of burnouts, dounuts, power drifting with that car.

The guy next door has 700 HP in his 1990 C4 with a 6 speed so far it holding up for him.

As for Auto the 700R4 they say can hold 650 to 700HP if built up for it then the 4L60E they say is stonger it cost me ($1000.00) for my 700r4 most places cost about $1400.00 on up with convertor I looked into the E-Bay stuff more I looked into them Stay away from them.

As for convertor how much stall do you need LOL I think 1984 to 1986 have a 2000 RPM stall convertor 1987 and on I think they are 1800 or 1600 stall with my engine mods I using a 2200 stall I was looking at a 2400 but the trans guy said it mite be too much for what I what the car for a every day street car with my motor combo.

My Vett is in the trans shop Now I had them rebuild mine but it would not shift It was a carry in job after I installed in the car.
I just put the car on a tralior a towed it down to the shop try to do this with a E-Bay trans that out of state.

I using a 700r4 with all the good hard parts inside HD clucth packs and a shift kit they say it good for 500HP.

The 700r4 and the 4L60E are overdrive Auto's Stock motor I was getting 22 to 25 MPG now the motor is breaths better makes more power more easly I dont have to give as much gas to keep the same speed up do to It's TQ motor I get more like 30 MPG as long as you keep you foot out of it If on the gas all the time you going to sucking the gas.

You hear Honda Car Ect getting 34 MPG but it a Honda car you driving a V8 Corvette.

I dont plan to drive the car hard but will hold up when needed.

Like I said I in the 340 to 360 HP range and around 427 TQ they say TQ what will fry the trans but TQ puts you in the seat and gives you the rush.

I also looked in to Full syn trans fluid ATF but Pete K a man thaty knows what up more or less said yes Full Sny make your Clucth plates last longer but harder on the hard parts so I much rather buy a soft part rebuild kit than a hard and soft rebuild kit and change the trans fuild out every 30000 miles the trans should last you with NON syn ATF.

Rearend gears work great but to low will make you run out of motor quickly these motors stock die around 4600 to 4800 RPM's.

My setup shouild be good for 5200 RPM's

To have the rearend regeared is about $1200.00+ for the ring and pinoin set including labor if you change the carrior out that more cash but if you going to do the rearend might as well have the posi rebuilt at the sametime extra $200.00 or so.

They have online places that swap out you core rearend core for there's but you have to pay for the new rearend ($1400.00) Plus core charge anouther ($1400.00) if you rear end they say it's good then they will refund your core charge back to you.

I have 307 gears in mine for the motor setup I think they are just right good lowend power and still can drive up on the HWY 2000 RPM'S at 70 MPH.

If you go with 373 you most likly be at 2500 RPM'S at 70 MPH 410 grears 3000 RPM's you get the idea more it revs more gas if you have a cam that made for High RPM's mite be a good thing like the guy next door and his 700 HP C4.

Low gears will get off the line faster if you can keep the tire from going up in smoke but hurt up on the HWY you lose topend speed also.

I like the twisties also as is HWY intechanges on ramps every now and then geting on it hard but not all the time.

I also looked into going with full coilover shocks for the money I just going to get a set of Adj Koni shocks as for tires full sticky tires are great but I don't need them I much rather have tires that last 50000 miles instead changing tires out every 20000 if you lucky at $200 to $300 per tire.

Be smart build your self a fun street car you can enjoy everyday that will not cost you every penny you make to keep on the road and keep on putting tires on it every 6 months.

Marv, I know what you mean, honestly in my mind I use to want an extremely fast car capable of 200, but after I thought about it a bit, I'd much rather have a 10 sec 1/4 mile car that tops at 120 or 140, just sounds smarter, plus, if I set my gearing ratios closer together like that, then it should actually help my mpg a little as I can keep my rpm's lower by shifting more often. However, that's not my expectations for this car (anymore, haha).

I used a program I found on the internet, just to see what it said my car would do as far as drag timings, and, I was fairly happy with the results whether or not they are going to be very true.

It said with 205 flywheel hp (which I assume the hp rating on it was flywheel) for a 3300 lb car (I guessed at the weight) that it should be:
1/8: 9.91 sec @ 69.7 mph
1/4: 15.46 sec @ 87.1 mph

I know those aren't fantastic times, and I'm sure my '01 Chevrolet Cavalier might be able to pull out better times, but it's what I expected. And it at least gives me a starting point.

If I did decide to change the transmission to be able to withstand a beating of 300 hp, should I find another automatic, or should I change it to manual. (I love manual to death but I don't know if I want to go through all those changes and cutting holes and junk)

If so, what transmission should I get?

Again, I'm not shooting for 300 hp, but I just want to make sure it'll withstand any amount of stress I put on it

 

[bartric]

Marv, it says you live in CA, but it's hard to understand what you're talking about half the time.

And most of the stuff I was saying was more metaphorical than literal in the last post.

We found out the gasket between the CFI and Intake isn't actually sealing it and it's allowing stuff in. So we're going to change that and see where we're at with the car.

 

[93Rubie]

With my 340 to 360 HP it showing mid 13"s so if you want 10's you looking at some big bucks to get that fast.

Not to hijack this thread but Marv02, I hope your car will be much faster than mid 13's.

FYI, Bartic your 84 Crossfire is still way faster than ANY Cavalier if you run under 16 seconds.
I have seen videos of guys running more or less stock X-fires to low 15 second passes, not to shabby for only 205HP.

 

[Marv02]

This what the online dyno telling me.

For my setup, as a guild line to go off of.

Not to hijack this thread but Marv02, I hope your car will be much faster than mid 13's.

FYI, Bartic your 84 Crossfire is still way faster than ANY Cavalier if you run under 16 seconds.
I have seen videos of guys running more or less stock X-fires to low 15 second passes, not to shabby for only 205HP.

 

[bartric]

Well, the program I checked it on, if he's running 340-360 flywheel hp, then he should be running between 12.7 and 13 sec 1/4 miles. But, it's just a program and can be wrong.

Yeah, I just want it running, and drivable right now, then I can worry about the details.

 

[Marv02]

You saying you want a 10 sencond car you need to a lot more power than 250 HP to get to those numbers.

As for Trans It sounds like you have a Manual 4 speed If I remember from my TA First Second and trid gear were close ratio and fourth was a overdrive type gear and gas mileage was not all that great.

I was telling you what trans for a Auto to look for.

There more than 1 way to get aroung the Injectors system if you want to go with a carb set up instead.

As for the spraying the intake with cleaner or crab spry to find a leak becarfull if there a bare wire down thewre a you dont know about it and it sparking It will cause a fire.

Marv, it says you live in CA, but it's hard to understand what you're talking about half the time.

And most of the stuff I was saying was more metaphorical than literal in the last post.

We found out the gasket between the CFI and Intake isn't actually sealing it and it's allowing stuff in. So we're going to change that and see where we're at with the car.

 

[bartric]

You saying you want a 10 sencond car you need to a lot more power than 250 HP to get to those numbers.

But that's the thing, I wasn't saying I wanted a 10 second car. Like I said earlier, it was metaphorical not literal. And I know I'd need a lot more than 250, I'd need about 750 to be more accurate.

Anyway, should have the gasket for the intake tomorrow, replace it, and then see if it runs any better.