Went to Milan to see if i got her finally figured out. First pass was a slippery 9.90 @ 139... I have had multiple problems with this car - but im finally getting the bugs worked out. However, last night added a few minor issues that i need to get help on from y'all.

I have the following to help diagnose my problem:

2000 ws6
w2w 346 ls6 blower engine
th 400 with brake - 4000stall
dts 12 bolt - 373s
d1sc @ 13-15lbs
3550 race weight
28.5x10.5 inch slicks
Stock cooling system/ thermostat - fans turns on at 208 and off at 202

1.) RPM/ converter/ 60' issues/ or bigger gear in the rear? I shift at 7000 - however i put my 4th converter in this year and now i feel it's too tight - but i actually can make it down the track with this new converter, the old one was just too loose and only made it 1000'. I go through the traps at 6100-6200. My 60' was a horrible 1.50 (two tenths slower then my old 4000 stall). Is the converter too tight now? Should i increase my stall speed from 4000 to say 4600? Do i need to jump up to a 4.11 gear? Or send the converter back and loosin it up a little?

2.) Blown head gasket? or some other jacked up radiator problem? After my 9.90 pass i let the car cool for about 20min and got back in line. Car was okay going down the track but i couldnt hook up and went 10.09 @ 134. Going down the return road, i noticed water literally being ejected out of the right front side of my hood. Looked at the temperature guage and it was at 200 then instantly shot over 250 within seconds- I shut the car off and poped the hood. I've never seen this before but the radiator cap was literally destroyed and coolant was spewing out and completely covered the passenger side of the engine compartment? What could cause this???

The cap was on tight - all fluids were filled adequately - What do you guys think??? If i left anything out that y'all need to know about my car please let me know so we can diagnose this problem. Gosh is this one depressing year. Any and all help is appreciated... Thanks!

Jayson

 

First, were you running on Thursday or Friday night at Milan? Thursday night was hooking well for the Stenod/Varsity Track rental. I was cutting decent 1.45-1.50 on MT ET Drag radials.

Are you eyeballing your RPM through the traps or looking a computer data scanner log? 6100-6200 at 139mph on a TH400 with a 3.73 sounds a litte bit off... as in 100% efficient converter. Either way you don't want to go to 4.11s on that car our your going to run out of RPM and hate it on the street.

Loosing up the converter gives you more power at the line certainly but I'd look at the suspension before tearing things apart this late in the season. What do you have for suspension in the shocks, torque arm and rear sway bar?

2) Does sound like a blown head gasket. The exhaust is preasurizing the coolant system and blowing the coolant out. Your temps are "OK" at high RPM because the water pump is still moving whatever coolant you have in there. Once you slow down, a half full coolant system will make for a hot motor in the return lanes. You can diagnose this by putting on the cap and giving the car a good 15mile run on the street and highway. Take 2 gallons of coolant and another cap to be safe.

Rick

 

I agree, sounds like a head gasket. Bob

 

Rick,

Thanks for the reply. I was testing on friday - the track was horrible, probably because they had a domestic vs import race which about 40 cars total showed up.

When i went through the traps i was eyeballing my autometer tach - the tach is very accurate in 2nd/ 3rd gear - maybe 100rpms off at most. It felt like the car was being "held" back in third gear - it didnt want to rev quickly like in first gear - the converter is probably still too tight.

I have all aftermarket suspension. Double adjustable shocks front (coil over) and rear - BMR LCA's, Panhard bar, front lower and upper A-arms, k-member, no front sway bar; Spohn rear drag sway bar, torque arm. Sub frame connectors - basically every suspension part you can purchase i have on the car.

It makes sense that i have a blown head gasket now. What should i do about the converter? Send it back and have them loosen it up OR raise the stall speed?

Thanks,

Jayson

 

Bob,

What would you reccomend me doing with the converter? Raise the stall speed? Loosen it up? Or both?

If the engine reached 250 degrees F, do you think something internally is warped? I probably should go through the entire engine to be safe then correct? What is the BEST head gasket i can buy for 15lbs of d1sc pressure?

Thanks for your help!

 

You really need to log the car somehow, otherwise you are flying blind. I dont know why you are having that many problems with converters but if you logged a pass you could see exactly what the converter was doing on the line and down track and it would be a lot easier to figure out what needs to be changed.

Most likely popped a head gasket but first make sure a radiator hose, heater hose, bypass hose ot something didnt pop off. If it overheated real bad it would come out of the filler cap on the overflow tank by the battery. If it overheated that bad it could be a head gasket, just make sure it isnt something simple first. GM MLS gasket should be fine for what you are doing, most likely detonation popped the gasket if it is blown.

 

Are you still runing the stock PCM? If so, the engine will go into shutdown mode if the overheating gets really bad. Certainly 250 is not good news but you're getting it shutdown pretty quick (probably within 10-15 seconds after the RPMs came down off the run) so I doubt you've hurt anything.

Like KP said, check all the hoses first but if the radiator cap actually popped it's got to be a gasket. Make sure the oil looks clean on the dipstick and oil filler cap before you try to refill the coolant and fire it up again for the cruise test I mentioned before. On the cruise test, the radiator cap may hold but you would see the overfill tank splattering coolant around the hood and battery area.

Once you take car of the gasket/coolant situation, then I would recommend you run the car on a good track night before tinkering with the converter. Milan will get ripped up with the street tire guys coming out for TnT. So it can be hit and miss sometimes. I'd recommended making passes at the North vs. South at Milan on Sept 2nd, or come down with us at Motown Muscle for our Norawalk track rental on Friday Sept 8th. I you don't get a good 60' on one of those track days, then it's worth looking at the converter.

Rick

 

Thanks Kev,

Yes i need to invest in a computer data logger/ tuner... That will come over the winter - need some big bucks - gonna get that FAST XFI system...

I'm gonna check all of simple things - but im pretty sure it's something bad - like the head gasket... Anyone changed this themselves? Thanks guys.

Jayson

 

Heads arent that hard to do, especially if you have MLS gaskets - no scraping

EFIlive or HPtuner has a black box logger so you can log passes without even having a laptop in the car. Honestly for what you are doing switching over to a standalone is a waste IMO, if you have a 99+ car there are some very nice custom operating systems out there for the stock PCM and a stock pcm/ignition will get you in the 8s.

 

Yes, I am running the stock PCM still, unfortunately. The engine did not shut down - or maybe it didnt have time to because i caught the guage rising very rapidly?

Changing the converter is not that big of deal for me - only takes little over an hour. I gotta just find that happy medium. If i could cut 1.3x 60' with a loose 4000 converter and now im cutting 1.5x 60' with a tighter 4000 converter is has to be too tight im assuming? I can borrow a data logger program and see what the converter is doing - but first things first, i need to figure this cooling issue. I will get their soon, i promise. I'm young, im young - give me time and i'll get er' right

Thanks guys, y'all are the best. I will try to make the N vs S race at Milan. Depends how fast i can get this thing fixed.

Jayson

 

What would you reccomend EFI or HP? Your car and mine are basically sisters - just yours in black and mine red What works for you should work for me.

 

If it was easy everyone would be running 8s the first time out, its a long road when you are looking for good ETs. While its fairly simple to bolt the right parts on and make the power getting a car down the track takes a little work and things break.

No need to be disappointed with a 9.90 @ 139, thats still haulin *** in my book..

 

As far tuning/logging stuff? Either one works fine really.

 

If I end up changing converters you should buy mine. 1.35 off the brake on a 28W and 144mph. I shifted at 7000 most of the time. TCT Converter.... with a 3.50 gear.

 

Alrighty, looks like i have a rather large to-do list for the weekend. Thanks guys. I'll keep ya posted with how she does next time!

Jay

 

I appreciate the offer and would accept. However, i'm committed to TCI. Thanks though!

 

Can I ask how much your car weighs and what kind of power (rwhp if you have it) you make? Just wondering what kind of times I should work toward with my setup.

Thanks, and best of luck with your car! 9.90's is hauling ***, broken or not!

 

Here's the ultimate cheat sheet for the basic heads/cam/intake swap work. Great details and pictures to walk you through the process.

http://www.ls1howto.com/index.php?article=3

Rick

 

Both tuner packages work well. I use HP Tuners and it's got everything I need.

The best bet is to talk to your current tunner and see what they use. Then you guys can share logs and tunes remotely via e-mail rather than having to stop by the shop all the time. Nothing like hitting a track that has Wireless Wide Band access and having your tuner chip in some help from the shop or home.

Rick

 

Car weights 3545lbs with me in it... And it almost made 550rwhp on a dynojet, SAE corrected.