254 MPH Sledgehammer 1988 C4 Corvette - Auto-Trend Repairs and Service Information Forums

SELLC · CERTIFIED POST WHORE

254 MPH Sledgehammer 1988 C4 Corvette

Rastus · UNSTOPPABLE!

Very nice, & very fast.

I'm not sure that I'd fork-out that sort of $$$ for a turbo-charged vehicle though, especially at the age it's at...

Shawnee_B · FAR BEYOND DRIVEN

Pretty cool. Callaway is about 20 miles from my Mom. Ex bro in law has a Callaway.

SELLC · CERTIFIED POST WHORE

Rastus wrote:
Very nice, & very fast.

I'm not sure that I'd fork-out that sort of $$$ for a turbo-charged vehicle though, especially at the age it's at...

Yeah but for 1988, at that time of course, it was pretty miraculous and just shows how fast these Corvettes can go...

For me it would be a dual shot (150 dry) (300 wet) which would equate to about 750 HP at the flip of the switch without having to hollow the frame or worry about things like heat-soak -- or even make a single internal engine modification for that matter!

I figure 750 horsepower is good for almost 200 MPH in a Corvette C4 with factory highway gear. It's not like a Corvette is built to drag race, that is more for the F-Body Camaro/Firebirds with solid axles.

I really hope to get my other customer pay projects done soon, as I would love to start modifying my own. The great thing about this car for me has been its reliability to tide me over and keep me wanting more in the meantime.

SELLC · CERTIFIED POST WHORE

Although I must say, IRS cars like the new Challenger are starting to turn the perception that an IRS car can't perform out of the hole in drag race conditions.

I still feel a solid axle is best for drag racing though... but technology is a marvelous thing. Perhaps that is why I am still impressed with the 254 MPH in 1988... Held the record for decades!

Try swinging the Challenger around the track at 254 MPH...

-- Edited by SELLC on Monday 14th of January 2019 10:54:43 PM

Rastus · UNSTOPPABLE!

Yo,

I know you get about 40-kmph with a 2.6 : 1 diff ratio & std diameter wheels.

Anyhow, with this set-up ( wheels ) you'll need to find 8,000 rpm from your motor, with a 1.0 to1.0 top gear-box ratio.

Most 5-speed gearboxes with over-drive, knock around 800-rpm off, when in overdrive / 5th gear, so a genuine 7,200-rpm should see you at a real 200-mph.

Shawnee_B · FAR BEYOND DRIVEN

Interesting to know what the 2003 Z06 is capable of. 6 speed manual. LS6 405HP at 6000.

Over on Corvette there is a discussion on redline. Some are saying between 6400-67.

LS6 was run for 100 hours at 6900 and guy posted that runs 6700

There is a rev limiter, believe set at 6500 from the factory.

I don't over rev or beat it, too bad but did hit the limiter once. It does work!

Shawnee_B · FAR BEYOND DRIVEN

Yup, that's exactly what mine did when I hit limit.

SELLC · CERTIFIED POST WHORE

Rastus wrote:
Yo,

I know you get about 40-kmph with a 2.6 : 1 diff ratio & std diameter wheels.

Anyhow, with this set-up ( wheels ) you'll need to find 8,000 rpm from your motor, with a 1.0 to1.0 top gear-box ratio.

Most 5-speed gearboxes with over-drive, knock around 800-rpm off, when in overdrive / 5th gear, so a genuine 7,200-rpm should see you at a real 200-mph.

I am not sure I understand your math considering the 1988 Sledgehammer Corvette had a final drive ratio of 3.54:1 and redlined at 6200 RPM @ 898 horsepower to a top speed of 254 MPH on 17 inch rims!

https://www.supercars.net/blog/1988-callaway-sledgehammer-corvette/

It also does the quarter mile in 10.6 seconds...

So something tells me your math may not be accurate if you think my 2.59:1 ratio needs 8,000 RPM's to achieve 200 MPH... Can you explain that to me Rastus?

Rastus · UNSTOPPABLE!

Yo,

The math is easy ! Jump in your car, & note down what road-speed you're doing, at 1,000 rpm intervals in top-gear, or what ever gear gives you 1 to 1 ratio through the gear-box.

Once you know what speed you get per 1,000 rpm, you can estimate your top-speed by your engine rpms.

Obviously, when I said std-diameter wheels, I was leaning / guessing at 14 or 15 " wheel, since the car was from the 1980's...

You get all sorts of wheel sizes today as you know, & that effects engine rpms, especially with the very large diameter wheels, where you need a numerically larger diff-ratio to get your power back with.

The way it works, is like this....

If you use your air-fill-valve as a tell-tale, & set it to 12-o-clock, & then rotate a wheel one full rotation, measure the distance traveled...Larger diameter wheels & tyres travel a greater distance per rotation.

SELLC · CERTIFIED POST WHORE

Ah, yes... 14 or 15 inch rims would probably require near 8k RPMs to achieve 200 MPH... I was wondering where you had gotten them figures confuse ... Now I understand! lol

As it stands, both the Sledgehammer of 1988 and my 1996 are fitted with 17 inch rims, but of course the Sledgehammer seen 17 inch rims well before the early C4's of their day which I believe was either a 15 or 16 inch rim.

Here is another cool video of a C4 Corvette, but this time its putting a whooping on a Z06 C6 in the quarter mile.

Modified LT4 C4 Corvette vs Z06 C6 Corvette

In that video you can really notice how tight the RPM's are, I am told that the C4 has a LS style digital ignition system, which is something I plan on looking into since the optic-spark is really a dated arc style ignition.

Rastus · UNSTOPPABLE!

SELLC wrote:
Ah, yes... 14 or 15 inch rims would probably require near 8k RPMs to achieve 200 MPH... I was wondering where you had gotten them figures ... Now I understand! lol
As it stands, both the Sledgehammer of 1988 and my 1996 are fitted with 17 inch rims, but of course the Sledgehammer seen 17 inch rims well before the early C4's of their day which I believe was either a 15 or 16 inch rim.
Here is another cool video of a C4 Corvette, but this time its putting a whooping on a Z06 C6 in the quarter mile.
Modified LT4 C4 Corvette vs Z06 C6 Corvette
In that video you can really notice how tight the RPM's are, I am told that the C4 has a LS style digital ignition system, which is something I plan on looking into since the optic-spark is really a dated arc style ignition.

I Liked that !!!

Sounds like he smoked the tyres in 3rd, to dig-in-deep in 4th...But that was also the moment he smoked ZO6...

Cool stuff !

SELLC · CERTIFIED POST WHORE

Although you do present an interesting point, @ 200 MPH (If the nitrous alone was enough to get there) I would literally be at my cars 6250 rev-limit, maybe a little over - which would be an absolute disaster to have the rev limiter kick in with 450 HP of NOS @ WOT in Top Gear! I am pretty sure that would be it for the engine, if not a complete crash and burn situation. This is yet another good reason to look into that LS style digital coil over conversion!

Something tells me I should buy a hardtop Corvette C4 and keep the convertible stock for leisure driving... But that is more money! I highly doubt I would do anything for at least a few years, but perhaps test and get aquatinted with the LS digital ignition on the kids car first, lol! Might as well test the NOS on his car first too! LOL, no point in messing up a hard-top or convertible Corvette!

Shawnee_B · FAR BEYOND DRIVEN

Pretty cool vid!

Rastus · UNSTOPPABLE!

SELLC wrote:
I highly doubt I would do anything for at least a few years, but perhaps test and get aquainted with the LS digital ignition on the kids car first, lol! Might as well test the NOS on his car first too! LOL, no point in messing up a hard-top or convertible Corvette!

Your Corvette is in awesome std condition, I'd leave it like that myself, simply because of rarity, & resale would be good.

I'd have your son hunt-you-down another couple of donor vehicles, & do exactly what he's done.

No doubt he appreciates all the learning & stuff about Hi-Po gear, but let him enjoy his own car...You never know, he may get peed-off & buy Lincoln just to spite you...

SELLC · CERTIFIED POST WHORE

Well there is more to the story than what I have said in the forums Rastus... The kid is no longer working with his Dad, and instead has decided he wants to sell/make milkshakes instead of having to work like a man on cars. Not much I can do, but I will be damned if I am going to pay his way. I could really care less about that Firebird either, Rastus... My Mercedes is still not running and we got in a bit of a fist fight while changing the transmission on Goldilocks because he didn't pay attention and left the speed sensor attached and a big ordeal ensued as a result of the transmission dangling by said speed sensor as transmission fluid pour all over the floor. Yes, the speed sensor was on his side, and I did ask him if we were clear while the trans was lowered down at an angle and still on the transmission jack. Apparently he did not like the way I got onto him about the dangers and seriousness of removing heavy automotive parts such as transmissions, so he hit me. Well, that did not end well for him and it was the start of what I consider this downward spiral he has been on... Shortly thereafter he was leaving his new job at the milkshake shack and got into an accident and totaled his Silverado truck. I question how he could even think of owning a vehicle like the Firebird while not gainfully employed. Currently he has problems just covering his new insurance at $280 per month, which increased $130 due to his little accident.

So, unless you would like to be the responsible party on the insurance and liability side of a 17 year old driving what amounts to nearly a race car on the street, then perhaps you might see clearly enough to understand that I have not been a bad guy at all... If you would like to pay his bills, fix his car and be responsible for his actions I can forward him your telephone number! I will even set up an account for you to send his insurance payments and any legal fees he might rack up! lol

It has no doubt been tough to see him pulling away, and of course I am having to work much harder myself now that he isn't helping with the little stuff that I have spent so much time training him to do. It is frustrating, but it is what it is.

That said, he can buy whatever he wants! A Lincoln, a Dodge - even a Ford if that is what he wants! But he will have to pay for it himself or it will be repossessed just like his Firebird! He currently owes me just short of $1,000 which is the amount he ran up on his credit cards (in my name) before he decided to just quit because he couldn't handle a tongue lashing about the importance of ensuring everything is disconnected on a transmission before pulling it out and having two people in jeopardy of getting hurt. He said Automotive was what he wanted to do for his career... I am not faulting him for exploring other avenues, but he damn sure will pay his own way if he is working to make someone else money! I won't pay his way or make special concessions for him like allow him to tie up my rack with his Firebird, that by all rights still needs quite a bit of work to be 100% daily driver ready. Currently I have to listen to him and his dreams of buying a new car, yet he is only 17 and has one more year of school - so there is no way he could afford it! Heck, he still owes me $100 more for his insurance that is due on Monday! I think he wants to buy a new car because his Grandparents have encouraged this independence he is exhibiting, which I feel has only manifested itself into laziness... He has a great Firebird, and once had a real nice truck... But he doesn't want to work anymore. It is really sad, and it breaks my heart, but all I can do is what I have been doing.

SELLC · CERTIFIED POST WHORE

And the more and more I think about it, right about the time he failed to notice the speed sensor cable on the Mercedes transmission is also about the time I also started to notice that he had lost the passion... No longer interested in learning, just hurry-hurry-hurry so he could finish up and hang out with his buddies... Often times leaving the garage a mess, tools not put away... Getting more and more cocky, more and more in a rush... I seen it coming, but I remember being young once myself too.. so I just let a lot of things slide. I hope his buddies and whatever pussy he is chasing is worth it... He is off to being his own little man now.. Probably have to start looking for his replacement I guess... It sucks, you train them then they go elsewhere! Never thought my own kid would do it to me though... kinda hurts but oh well.

Rastus · UNSTOPPABLE!

I'll keep out of family business...

Make him an offer to buy the Firebird, to help pay back his debts sooner, & you'll have your donor car for the 200mph barrier.

Using good quality hand-cleaner in-a-bucket of hot water, & then scrubbing with a broom should lift all of the transmission fluid from the floor, without leaving any stains.

SELLC · CERTIFIED POST WHORE

Rastus wrote:
R1 - I'll keep out of family business...

R2 - Make him an offer to buy the Firebird, to help pay back his debts sooner, & you'll have your donor car for the 200mph barrier.

R3 - Using good quality hand-cleaner in-a-bucket of hot water, & then scrubbing with a broom should lift all of the transmission fluid from the floor, without leaving any stains.

R1 - Oh sure Rastus... You say that after picking at the family scab known as the Firebird! Now its bleeding again and you want to keep out of it!? LOL - I thought you were made of sterner stuff...

R2 - Make him an offer to buy it!? LOL! HELLO! HE OWES ME MONEY! Is that how a car loan works in Australia, Rastus? Where if you don't make your payment they come write you a check for the car!? Or do they just repossess it and sell it? I had my F-Body cars when I was young so honestly outside of a 1/4 mile drag car, I have no interest in seeing the Firebird do 200 MPH. In fact, my desire to even work on it any further is fleeting because I already have a Corvette AND a Mercedes that need fixing. If you can remember back far enough Rastus, you should remember this car was pretty much a SHELL when he got it. That is a lot of work and time over the years under the false pretense that I had myself a partner worthy of the effort. I feel cheated!

R3 - I was just amazed that the entire weight of the transmission was suspended by what amounts to two wires running to the speed sensor! I mean it literally hung there until I was able to retrieve a 10mm socket wrench to remove it! LOL, and the kid didn't even bother to clean up the mess after either... So yeah, now I have to raid my stock of speed sensor harnesses and replace that too...

Rastus · UNSTOPPABLE!

SELLC wrote:
Rastus wrote:
R1 - I'll keep out of family business...

R2 - Make him an offer to buy the Firebird, to help pay back his debts sooner, & you'll have your donor car for the 200mph barrier.

R3 - Using good quality hand-cleaner in-a-bucket of hot water, & then scrubbing with a broom should lift all of the transmission fluid from the floor, without leaving any stains.

R1 - Oh sure Rastus... You say that after picking at the family scab known as the Firebird! Now its bleeding again and you want to keep out of it!? LOL - I thought you were made of sterner stuff...
R2 - Make him an offer to buy it!? LOL! HELLO! HE OWES ME MONEY! Is that how a car loan works in Australia, Rastus? Where if you don't make your payment they come write you a check for the car!? Or do they just repossess it and sell it? I had my F-Body cars when I was young so honestly outside of a 1/4 mile drag car, I have no interest in seeing the Firebird do 200 MPH. In fact, my desire to even work on it any further is fleeting because I already have a Corvette AND a Mercedes that need fixing. If you can remember back far enough Rastus, you should remember this car was pretty much a SHELL when he got it. That is a lot of work and time over the years under the false pretense that I had myself a partner worthy of the effort. I feel cheated!
R3 - I was just amazed that the entire weight of the transmission was suspended by what amounts to two wires running to the speed sensor! I mean it literally hung there until I was able to retrieve a 10mm socket wrench to remove it! LOL, and the kid didn't even bother to clean up the mess after either... So yeah, now I have to raid my stock of speed sensor harnesses and replace that too...

LOL !!!

R1. What goes on between your son & yourself is your business. You're Dad, so you're supposed to know best. Not an easy job...

R2. Sorry mate, I thought he bought & paid for all that stuff with his own hard-earned. Don't sell it...It's an awesome street-fighter !

R3. Well, you never know, it may still work...You can always test for continuity once you pull-her-out,

SELLC · CERTIFIED POST WHORE

Just because I'm his Dad doesn't mean that I know what is best for him. What I do know is that he is young and that can be rather expensive... I try to help all that I can, but it comes a point where he starts getting that Democrat mentality that everything should be free to him and without consequence. I have been there, I know.. We have all been there!

He did buy the car, for a very small amount. I helped him quite a bit along the way and there is still much more to be done. I don't have any plans on selling the car currently, but if he fails to make his payments it will eventually be sold off to pay his debts. When he is 18, if he has paid his debts the car will be given to him and he can insure it in his name... from there it is all on him. Until that time, I don't think selling/making milkshakes is going to advance the Firebird much further than how it sits today... He seems to work every day from the time he gets off school until about 8pm, which is a hell of a lot more than he did for me... Usually when he got home from school he would eat and sit around for a few hours watching TV or on his phone... After hours of begging and pleading with him to get working he would do a few hours work, rushing and just trying to do the minimum - then off to the gym until 10 or 11 at night. Weekends were getting to be hit and miss, but he doesn't seem to have any problems working weekends for the milkshake joint. Meanwhile I just paid his insurance, of which he claims to be $100 short until he is paid on Sunday... I was also assured by everyone in the family that my working him was affecting his grades! Yet this semester he seems to still be failing a few classes, which means this summer he won't be able to work much as he will have to enter Summer School to ensure he graduates on time... Then there is the fact that with each passing day I grow more and more insulted - to the point I don't really know if I could ever count on him again! At least not the level of trust he had prior to this idiocy.

That said, you brought it up... It was your suggestion that my use of the car for a week somehow impeded his being able to "enjoy" the vehicle... as if to imply somehow that I didn't have much better cars or things to be working on... I hardly think spending two days installing his interior and highway testing the vehicle to ensure its roadworthiness was anything but me reminding him what he had, because at the time he said he was "over the Firebird" and wanted to buy a new Challenger Hell Cat! LOL, a car that cost more than I paid for the home he is currently squatting in.... Now he is convinced he can lease his way thru life at a fraction of the cost.

No Rastus, I am just a bad guy preventing my son from enjoying his car.

Rastus · UNSTOPPABLE!

SELLC wrote:

1.That said, you brought it up... It was your suggestion that my use of the car for a week somehow impeded his being able to "enjoy" the vehicle... as if to imply somehow that I didn't have much better cars or things to be working on...
2.I hardly think spending two days installing his interior and highway testing the vehicle to ensure its roadworthiness was anything but me reminding him what he had, because at the time he said he was "over the Firebird" and wanted to buy a new Challenger Hell Cat! LOL, a car that cost more than I paid for the home he is currently squatting in....
3.Now he is convinced he can lease his way thru life at a fraction of the cost.

LOL !

1. Whoops...All I was suggesting was that it would have been nice to read something like " Son, I'm f***ed at the moment for transport as you know...Do you mind if I use your car over the festive season to get to the Casino & stuff ?...That way, I can use the time too, for Road Worthy test drives, so it will be legal-tender sooner"...

But we didn't get that...We got "Oh, I'm using my sons Firebird to get to the Casino...Geez it's loud, sounds like Nascar"....etc etc Implying that you were having all the fun, not him.

2. Sounds like he's watching "Breaking Bad" re-runs lol ! Show him how interest repayments work on a calculator, & include original price, final payment total amount paid, & current market value of vehicle...

3. Nothing is for free...Just tell him to ask Mr.Obama !

SELLC · CERTIFIED POST WHORE

Rastus wrote:

LOL !
1. Whoops...All I was suggesting was that it would have been nice to read something like " Son, I'm f***ed at the moment for transport as you know...Do you mind if I use your car over the festive season to get to the Casino & stuff ?...That way, I can use the time too, for Road Worthy test drives, so it will be legal-tender sooner"...
But we didn't get that...We got "Oh, I'm using my sons Firebird to get to the Casino...Geez it's loud, sounds like Nascar"....etc etc Implying that you were having all the fun, not him.

That is pretty funny Rastus.. I was never fucked at any moment, I had the Corvette! Before that I had the Cadillac before his buddy backed into it - never mind I come home from out west to a broken rack and pinion... Prior to that I had that Black 420 SEL and prior to that ole' reliable Goldilocks, the smoke silver 560..

So PLEASE, explain to me where I was ever "fucked"? It was more or less HE WAS FUCKED, having told me "Dad, I am over the Firebird". If he was "over it" then what you're saying could not be true!

Do you mind if I ask how long you lived with your parents? Because I am getting the impression that maybe you haven't fully grown up! LOL

Rastus · UNSTOPPABLE!

I was kicked-out for smoking weed when I was 2nd year apprentice..." Either the weed goes, or you go", so I left. Would have been about 18 I think...

Anyhow, so your son was struggling with the cars interior, meaning he needed a hand, & was sick of going around in circles, & was demoralized...But IMO, that doesn't mean he was "over" the car...He just needed time away from it, to recharge the enthusiasm.

He "did" source 2 x cars, repair & swap over bits & pieces to get to the 95% finished stage remember...

And we here didn't know about the labor hassle he was causing you, or the accident he had...I understand "now" that it made sense for you to use it in need...

None-the-less however, I would have been peed-off after doing so much work on that car, to have it driven on salted roads.

Complicated family stuff here going on...And I can't offer legitimate replies since we're not in full view of everything that's been going on SELLC.

I'm not attacking you LOL !

SELLC · CERTIFIED POST WHORE

Rastus you fail to realize that A LOT of people helped to put him in that car, and a few of them people thought that he would be an asset to their own projects that are here - myself included.

What you suggest about salt is absolute nonsense as the vehicle is parked/stored outdoors anyway! And I am sure the struggle is real for him, but if you need time away from your girl and during that time she gets fucked by someone else - who's fault then?

So you're saying that driving a car that is stored outdoors and the fact he was "on a break" with the car are reasons that I should feel bad? Because I was fixing his car and test drove it?

Wake up Rastus! The deal was that until he finished my Mercedes - THE CAR WAS MINE! Now that still applies, but he has also run up some debt that he was made fully aware of that his car was the collateral for.

Obviously I am well aware that the time I used to spend helping him with his car will now be spent on my Mercedes.

Shawnee_B · FAR BEYOND DRIVEN

Sorry for the probs. Raising kids is TOUGH! Keep the tough line, I did. He will come around.

SELLC · CERTIFIED POST WHORE

Thanks Shawnee! He's still a good kid, but I worry he could spoil easily.

I am still looking into that LS style ignition conversion kit for the LT engines...

Rastus · UNSTOPPABLE!

SELLC wrote:
1.Rastus you fail to realize that A LOT of people helped to put him in that car, and a few of them people thought that he would be an asset to their own projects that are here - myself included.
2.What you suggest about salt is absolute nonsense as the vehicle is parked/stored outdoors anyway! And I am sure the struggle is real for him, but if you need time away from your girl and during that time she gets fucked by someone else - who's fault then?
3.So you're saying that driving a car that is stored outdoors and the fact he was "on a break" with the car are reasons that I should feel bad? Because I was fixing his car and test drove it?
4.Wake up Rastus! The deal was that until he finished my Mercedes - THE CAR WAS MINE! Now that still applies, but he has also run up some debt that he was made fully aware of that his car was the collateral for.
5.Obviously I am well aware that the time I used to spend helping him with his car will now be spent on my Mercedes.

R1. Cool ! His thread read like he was doing-it-all mostly himself, with a little-help from Dad...

R2. Well, if she moves on, it was probably the right decision to have that break...Saved lots of $$$ down the road lol !

R3. Your words my friend, not mine...But you did post at one stage, the Firebird was to be the winter car...( We didn't know about the other stuff until today ).

R4. Yep, it seems I need another coffee...

R5. Goldilox can't wait to get back on the road again I'm sure !

SELLC · CERTIFIED POST WHORE

Rastus wrote:

R1. Cool ! His thread read like he was doing-it-all mostly himself, with a little-help from Dad...
R2. Well, if she moves on, it was probably the right decision to have that break...Saved lots of $$$ down the road lol !
R3. Your words my friend, not mine...But you did post at one stage, the Firebird was to be the winter car...( We didn't know about the other stuff until today ).
R4. Yep, it seems I need another coffee...
R5. Goldilox can't wait to get back on the road again I'm sure !

R1. His thread reads exactly how it all went down, but on topic. Going off script because you actually think I'd rather be driving a Firebird than my Corvette! LOL, calming that I had a good time like a male gynecologist doesn't... pfft..

R2. If it had tits or wheels it's gonna cost you money

R3. The winter car stuff was more or less to motivate him, and that is all pre-Zephyr... You know this already!

R4. So I have a Guinnie Pig car that ever penny I spend on it will be that much more the kid will have to pay me the day he wants to retake ownership. Complete with slicks... hmmmmmm lol

R5. I can't wait either, this 3.0 V6 is cramping my style! I forgot how long ago I put $20 in the gas tank it has lasted so long! pffft... $20 might not even get you out of the Reserve on a W126 and that is with Persian Pierre Premium fuel... I still use Premium in whatever I am driving, old habits die hard.

Shawnee_B · FAR BEYOND DRIVEN

SELLC wrote:
Thanks Shawnee! He's still a good kid, but I worry he could spoil easily.
I am still looking into that LS style ignition conversion kit for the LT engines...

I sure love that LS in mine, the whole C5 package actually. Read a couple great books. All Corvettes are Red is the C4-C5 story, excellent read. The who, why, where, everything. No Time to Cry was also excellent, more of a life story mixed with corvette.