1998 C5 Roadster

Update your progress on your various car projects.

Moderators: MostMint, wxo, Fred32v, Basement Paul, ttamrettus

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MostMint
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Location: planning a race

Re: 1998 C5 Roadster

Post by MostMint »

The trans can be shifted my RPM or MPH. When the ring gear was changed Hutter had to recalibrate and missed it a little. The fuel cutout is by RPM. Need to raise the RPM max or lower the shift point at WOT.

Just a guess as maybe the Vette is different than the SS.
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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GMJohnny
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Location: Auburn Twp, Oh

Re: 1998 C5 Roadster

Post by GMJohnny »

I called Hutter's today and set up going in to the dyno on Tuesday. They indicated that it was difficult for them to
get the 2-3 shift correct by driving on the street, because of the speed you are at when you shift. They also knew
they were close, but may not have gotten it correct. A few passes on the dyno and some tuning should help a bit.
They also will make provisions for the new intake and x pipe. Maybe Wednesday night at the track again..............
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GMJohnny
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Re: 1998 C5 Roadster

Post by GMJohnny »

Well, Tuesday pm I was at Hutter's to finalize the rear end swap deal with a couple of passes on the dyno.
They were supposed to get the work done during the day while I was at work, but couldn't get to it til late in the day.
That was OK by me, as I always enjoy talking to them, asking questions and watching them romp on my
car on the rollers. The final outcome showed my rear wheel horsepower to be 309, which was 4 lower that the first
time I took it to the shop. They explained that it was due to the gear change, almost apologizing for the fact that the hp
number was lower. I told them I'd be glad to take a dyno run that showed I made only 100 hp, if the car would go low 12's!!
They laughed and seemed relieved. They did some shift point changes, trans pressure changes, and leaned it out a bit somewhere in the run. Apparently, we were too rich somewhere. I asked them if I'd get a second of my e.t. from the tune, they really laughed then!! I was not able to street test the tweeking, however, because it rained like crazy on the way home. I tried to test it, but was real leary of winding up in a ditch. We will have to give it another test at the track. Hopefully these changes, coupled with the colder 57 degree temperature tonight we will net some better times.
GM
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wxo
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Re: 1998 C5 Roadster

Post by wxo »

Hey, Johnny, I know where there is a good runnin' LS1 with 317 HP just waiting for someone to make use of it. :wink:
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GMJohnny
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Re: 1998 C5 Roadster

Post by GMJohnny »

Hey Walt ..... I think you should build it and put it in the GTO. You already own it free and clear, and selling the rest of the Z28 should help pay for the build.

GM
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GMJohnny
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Re: 1998 C5 Roadster

Post by GMJohnny »

So BP and I went to the strip on a 44 degree night, with a chance of rain. My first pass was a 12.77 @ 109.21. I was pretty excited that my first pass was my best ever, so I kept trying. The problem was that the track couldn't support the horsepower. I had terrible trouble getting the car out of the hole, and to make matters worse, I was breaking traction at various points while going mid-track. It was like being on a greased surface. I had 2 runs that I aborted because of slippage in mid run. Many of the other racers were compaining about the same thing, and the track owner was even making comments about it. What little glue they had on the line was not helping anybody. Unfortunately, the cold that I thought would help me, hurt me. Half way through the event, the wind shifted to a head wind, so my mph dropped as well. I was able to muster up a 12.86 @ 105.76 in eliminations, but never was able to get the killer 60 ft times of the week before. I guess I need to find a night when it is going to drop into the 60's, after a sunny 70 degree day, and hope the track can help the cause. In any event, we're getting closer to the goal of 12.60.
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GMJohnny
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Re: 1998 C5 Roadster

Post by GMJohnny »

So my weather prayers were answered on Wednesday. It was sunny all day, low humidity and in the mid 60's all day.
BP and I were unable to decide whether we should go to the track or not, but he kept saying the weather was perfect, so we decided to make the trek. I was able to pull off a 12.71 @ 108.18 as a best with 60' times in the 1.8's all night long. The track was able to help the street tires get their grip, and only one time ( in eliminations of course ) did I have wheel spin issues. There was a very slight ( 2 mph maybe ) tailwind, and the air temp when I made my best pass was 60 degrees.
I was able to back up the 12.71 with 3 other passes in the 12.70's and one 12.80. I know that cold will help to get me into the 12.60's, if the track will hold, but there is such a fine line with traction. I may have to look to one more horsepower tidbit to eek out another tenth so I'm not relying on weather so much. In the mean time, consistent 12.70's is a good thing!!
markss327
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Re: 1998 C5 Roadster

Post by markss327 »

12.7s and it probably corners pretty good too. :lol:
Nice.
-Mark
2012 Impala LT 3.6 VVTDI
300hp - a bit much for FWD!
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GMJohnny
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Re: 1998 C5 Roadster

Post by GMJohnny »

It does corner very well, but I think its abilities to corner well far outweigh my abilities to make it corner well. I'm still learning how to make it go straight!!! :lol:
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GMJohnny
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Re: 1998 C5 Roadster

Post by GMJohnny »

Since my last post, I have done no major improvements to the Vette, and that's perfect. I gave it its annual wax job, and detail. I purchased a crappy scissor jack at Carlisle and made it work to lift one corner at a time, so I could remove the wheels to polish them. Other than that, I've been enjoying many warm nights and days, and have only been caught in the rain once. I'm around 31,800 miles. I will try to hit the strip toward fall when things cool down, until then, I'm loving summer!!
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GMJohnny
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Re: 1998 C5 Roadster

Post by GMJohnny »

So I finally pulled the trigger on a project I've been meaning to do since last fall. I removed the polished
aluminum 5 spoke wheels from the vette and put on 2003 painted 5 spokes instead. I just could not handle
the amount of upkeep with those wheels. They looked sweet when clean, but I never could keep them
clean to my taste. These should do the trick, and be a bit easier to maintain!!

I was able to jam all 4 wheels in the car for the ride to and from the tire shop. ( 3 fit in the trunk with the top
up, 1 riding shotgun. ) I took advantage of a warm, dry day in February to accomplish the task. I really
can't wait for spring to come, I miss the ride!!

GM


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GMJohnny
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Re: 1998 C5 Roadster

Post by GMJohnny »

The long winter is over. The Vette goes back to Hutter's tomorrow for cylinder
heads and cam shaft. I have to beat a certain Cadillac. This should do it! From
what I've read, I should get around 80 hp from the work. I talked to the guys at
Hutter's and they said they have equivalent packages in cars with equivalent
weights ( but with what I'm certain is more free flowing exhaust, as I'm keeping mine
stock looking ) going mid to low 11's. I'm shooting for 12.0. Trying to do this on
street tires and looking totally stock. More to follow......

GM
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Fred32v
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Re: 1998 C5 Roadster

Post by Fred32v »

Hmmmm.
Fred32v
GMC Canyon Crew Cab Short Box 4x4 V6!
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GMJohnny
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Re: 1998 C5 Roadster

Post by GMJohnny »

Wow, it's been a while since I posted on this vette. Early spring, as posted, I had a cam shaft installed.
Since then, I had the converters cleaned out and installed a new air filter. Aside from the air filter, the
car still looks bone stock, cast manifolds and all. The last pass through the dyno, I was at 357hp at the
wheels. Hutter figured that was around 425hp at the crank. ( Eliminating the cats and going to the open
filter was good for over 25 hp. ) Since doing the upgrades, I've run into a shift solenoid or torque converter
issue, as indicated by the check engine light and codes on the scan tool. This shifting issue gives me fits
when shifting. The car now revs 7000, but won't shift when it should, and therefore I end up hitting the rev
limiter mostly in 2-3 shift, but sometimes in 1 -2 also. I've had it to the track several times this year, with a
best going into the fall of 12.54 @ 111 mph. We blasted to Thompson yesterday for one final try to make it
shift, as I knew there was more time in it, if I could just get it to shift. Well, long story short, I got a pass
that I wanted. 12.33 @ 113 mph. ( my 1/8 mile time was 7.99 @ 90.65 mph ) I was pretty happy with that,
but want to say that to make it shift 2 -3 on that run, I lifted and shifted like I was driving a stick, and it went
to the next gear. I feel that when shifting correctly ( trans work to be done in the spring ), it has at least
another tenth or possibly two left in it. My 60 ft times are high 1.8's, with wheel spin at a minimum. I also
feel that lifting is causing me to lose speed at the top end, maybe a mph or so. It really rolls when you get
the cam shaft working. All in all, I'm very pleased that the package is coming together so well, as the goal was
to be near 12 flat on street tires. It's already well faster than the Z06's from its time, faster that stock c6's,
and now there's this certain Cadillac that is no longer faster than me! I'd also like to tell BP and Mostmint
" Nice doin' business wicha! " It seemed like an eternity getting faster than their TA's!

Fred32v told said to me yesterday, " if it would shift right, you're almost in the 11's." Which got me thinking....
Hutter's thinks I need long tube headers to really help. I don't know if I want that, but I have all winter to
think about it. When is a car really fast enough?

GM
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Maverick
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Re: 1998 C5 Roadster

Post by Maverick »

When is a car really fast enough?
Probably when you're faster than other Tiresmokers. :mrgreen:
Maverick
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