1998 C5 Roadster

Update your progress on your various car projects.

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GMJohnny
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Post by GMJohnny »

You never forget the good stuff!!!
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GMJohnny
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Z06 Intake Install

Post by GMJohnny »

So, in early October, I purchased a used Z06 intake manifold from Hutter racing. Finally, time came to install the piece. A quick trip to Fred's Garage ( where the car is stored ) and we ready to work. I got to the garage and it was already being heated! Fred32v and I got to work and we were able to perform the task in about 2 1/2 hours, which wasn't bad, because we had never done an LS intake before. The job was not terrible, and my homework was done correctly, as I didn't have to go and shag parts in the middle of the job to complete the task. I had studied several web sites and had my trusty shop manual handy, a blend of the two sources netted the finished product.
Several things were really different about this job. Firstly, there was no need to drain water to do the job. I even changed some coolant tubes under the intake, and lost only a few ounces of radiator fluid. Secondly, there were no tin "Oldsmobile-esque valley pan" gaskets to wrestle with on the install, only rubber rectangles at each port. Thirdly, it didn't take 3 guys to lower the intake on, as it was light enough to easily carry with one hand!
The horsepower increase is supposed to be around 6-8. Not bad for a small amount of money, and it made for a good time on a cold day. Next week we look to install a set of shorty headers ( or maybe one at a time depending on difficulty). Soon after will come a rear carrier change and possibly a new higher stall converter. The goal is to be quickest at Carlisle!!

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GMJohnny
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Post by GMJohnny »

So, I promised that I'd put on a set of shorty headers. I did, and took them off, and put them on, and took them off, and put them on and finally, took them back off to stay. I had purchased a set of Hooker's from ebay. They are ceramic coated, and on-line sell new for around $700.00. I paid $300. We put them on ( for the first time ) in about 4 hours, with some engineering slowing down the process ( mostly with studs and lining up the exhaust pipes. ) When we started it up for the first time, there was some exhaust noise, not coming from the pipes, but from the head area. So we decided to change the gaskets from the stock ones ( which were steel and supposed to fit and seal ) to a set of Fel-pro's from Summit. We did the swap, and still got noise. We struggled to seal up the passenger side. So, an extremely long story short, the passenger side header was on and off at least 5 times, trying various gasket combos, wrong gaskets, sealants, etc. Finally, after the last try, I punted and went back to the stock manifolds. The Hooker's did not have enough weld around the port to support a stock gasket wihtout leaking a bit. I did not think it was worth the 6 hp increase to have to worry about undependability, so stockers are back on the car. ( This is 3 weeks worth of fooling around here!! ) Now I am going to sell the Hookers and work on getting the rear end changed and torque converter as well. I am also going to let my hands cure from the scrapes and scratches that went along with installing the headers!!
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MostMint
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Post by MostMint »

So you can't have some extra material added then machined flat?

This looks like a job for Racin'Jacin. I'm sure if it was a Studebacker engine he'd probably just fabricate the headers himself. This should be easy. 8)
[quote="Basement Paul"]Is that a mint rocketship on the hood?? :shock:
-BP[/quote]
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GMJohnny
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Post by GMJohnny »

I could have had someone weld around all of the holes and then machine it flat. I did not want to go through the pain or expense of it. I didn't know what welding would do to the ceramic coating. I also didn't like the potential undependability of needing to put gaskets in cause one blew out. I also was not a fan of the way they bolted up to the exhaust. What I really want to maintain is the turn-key-ness of the car. I won't deal with having to wrench on this car before I drive it. That's the whole reason I got rid of my Oldsmobiles.
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TireSmoker
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Post by TireSmoker »

GMJohnny wrote:That's the whole reason I got rid of my Oldsmobiles.
I thought it was because you just got tired of gettin crushed by Chevys... :-)

-Dave
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Basement Paul
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Post by Basement Paul »

If you can't beat 'em, join 'em...

-BP
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Racin'Jacin
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Headers!

Post by Racin'Jacin »

Ahh Guys!! - Zoomies REALLY are the best - they're loud enough that you wouldn't even notice a pesky little exhaust leak!!!! ha ha ha


But seriously I know what you mean - I have manifolds on my old truck and REALLY want to free up the exhaust a little - so I am searching for some of the factory truck manifolds which are quite a bit bigger than the car ones. My truck is a tad TIGHT to work on (probably a cake walk compared to yours) but still I only wanna do this once!!!!

Racin'Jacin
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GMJohnny
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Post by GMJohnny »

Amen to only doin' them once!!! Have you tried to port out the stock manifolds? I was able to do it on a set of Olds manifolds I had. I don't know how they performed compared to stockers, because they never made it on the car, but I am sure that any amount of material removed would help the gasses get out quicker.
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GMJohnny
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Post by GMJohnny »

So, the rear end change process is now under way. Tomorrow I take the 3.42 carrier I purchased to Hutter Racing. They are going to check it out to make sure that it is what I think it is before spending the $ on getting it installed. They are also ordering up a torque converter that will/should stall around 1900 to replace the 1400 rpm stocker. Hopefully, these mods should get me solidly into the 12's, with the goal being around 12.6 / 12.5.
I have done some homework online and guys going from 2.73 to 3.42 have gotten 3.5 - 4 tenths. The converter should be worth .1 or .2. If you subtract this from my 13.09 best, you should be in the mid 12's solidly. I have also added the x pipe and the z06 intake since the last time I ran it. Is low 12's concievable? Time will tell. The first stock z06's were running what I am hoping to achieve. I'm still on track to have it ready for spring Carlisle.
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GMJohnny
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Post by GMJohnny »

So Wednesday I got to take the vette out of storage. Fred32v and I did some tinkering with it before we took it for a spin. The keyless entry remote was not working ( I feel due to the fact that we disconnected the battery many times when we were working on it in the winter ). We read the owner's manual and it programmed up quickly. I also had to reprogram the tire pressure sensors. It seems as though the guy who mounted the tires didn't read my masking tape labels when he put my tires on the rims. The car thought the left front was the right, and vice versa. It took me till the end of the summer last year to figure it out, and I procrastinated the fix, largely because I didn't know how to do it. That repair took 5 minutes also, and the internet gave me the easy steps to reprogram. Fortunately, I had a big hunk of Kohler 25hp flywheel magnet lying around ( from a motor at work that took a dump ) that took the place of the $150.00 tool the instructions called for to do the repair. Fred and I looked like pros, until we left the valve stem caps on the decklid when I went down the road. DUH! Now I have a brand new set of chrome caps to start the season with. The weather has been so nice, that I have had the top down twice already, and am looking for reasons to drive. The kids said they needed milk tonight, and I was over-zealous to go and get it!! It's nice to be back on the streets again!!
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GMJohnny
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Re: 1998 C5 Roadster

Post by GMJohnny »

So the rear end / torque converter swap was done the day before I went to Carlisle. I was afraid to trust the car so freshly re-assembled, and the rear end was kind of a question mark also. I now know that I could have trusted it. The gears were checked by Hutter's before the install, and I have no weird clunks or banging associated with the install. The car is way faster than it was before, and I'm able to brake torque it to 2000 on the line. Drivability is not seriously different than before, the only difference that was noticeable was how quickly the car gets to 4th gear under normal driving circumstances. The automatic shifts are literally 1 - 2 seconds apart. The car lugs overdrive very well. I had my wife in it Saturday night with the top down and asked her if she noticed a difference in feel of the car. She noticed none. (Perfect!!)
The exhaust noise is no different, even with the rpms being higher at cruising speed. I tried a no traction control 2000 rpm burn out tonight and the Bridgestones performed pretty well, with only minimal tire spin. The car has a tendency to chirp going into second gear with a bit of sliding around, but it is managable. The midrange and bottom end power seems very good, and I haven't really tried going over 90 mph, so I don't know about the top end speed. I'm going to the strip on Wednesday night for Thompson's first grudge race night of the year. The weather is supposed to be dry with a high of 75 degrees. A bit warmer than I care for, but it should give me a solid baseline for what the car can do. :D
markss327
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Re: 1998 C5 Roadster

Post by markss327 »

GMJohnny wrote: The car has a tendency to chirp going into second gear with a bit of sliding around, but it is manageable.... :D
Like, this is a problem??? 8)
-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 »

I have been working real hard to make this car have that "problem!" It is the fruits of my labor ( and $ ). :lol:
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GMJohnny
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Re: 1998 C5 Roadster

Post by GMJohnny »

So I just got back from a rain-shortened Wednesday night. The temp was 80 degrees and sun when I went to the track. It was 80 degrees and SERIOUS threat of rain when I left. BP aborted the mission because the threat looked severe at his place when he would have had to leave for the track. The vette ran a best of 12.89 @ 107.18. My best 60' time was 1.86, with no wheel spin ( after a smokey burnout ). 1/8 mile et of 8.31 @ 85.69. My top end speed was off from 108.4, but I think I know why. The car seems to be over-revving 2nd gear. One run ( there were 4 total ) I even bounced off of the rev limiter. The crazy thing about this car is you have no manual control over trans shift. I tried to shift manually on one run to lower the rpms and the car would not let me. I have to take it to Hutter's and have them retune that portion. I also think I will have him put the car on the dyno to see if he can't tweek it a bit more. After comparing my slips to last year's best, the car is faster et wise and speed wise until the end where it drops off a bit. That I attribute to 2nd gear over-rev. We'll see. I am going to see if they can get me into the shop next week for a short run. All things considered, the 12.89 is pretty good on an 80 degree day. There should be a couple of tenths in cooler weather. I think that with a little work and some good weather we should still be able to get to the 12.60's this year without too much trouble, maybe even the high 50's. I'm keeping my fingers crossed! :wink:
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