rdm20fan

Hi Guys,
I had a few updates that I thought I would share.

I took my 93 SC400 to the track yesterday (6-3-14)
I did about 6 runs
ET range from a 13.0 - 12.5 (Street tires and a lot of wheel hop)
and my MPH ranged from 119 - 126 mph
the 119-122 mph was at 18 psi
and the 126 was at 20 psi

I still have to upload the videos to youtube, but here is one my buddy took.

https://www.youtube.com/watch?v=L9Q3...ature=youtu.be

According to Great Lakes Dragaway's HP Calculator I put in 3800lbs with me as driver and trap speed of 126.6 and it's giving me a net HP of 601 :-)
That made me pretty happy.
http://www.greatlakesdragaway.com/in...page=analyzers

I'll try and post photos of the time slips, and videos

Car has 1st gen 1UZ, Stock heads & Cams. Upgraded springs.
Ross Pistons W/Pauter rods.
ARP head studs.
Stock ECU and additional injector controller 16 fuel injectors.
CM Racing twin turbo kit.
Getrag 6-speed

rdm20fan

I might just be me, but that is one sexy sounding SC
...................................................................................





Twin Turbo Lexus SC400 19 psi
12.59 @ 123.42 mph
Neon SRT4
13.45 @ 113.13

BS ISF

get some DR's on that sweet SC and run some low 11's high 10's!

rdm20fan

Working on it.
;-)

rdm20fan

Hey Guys,
My Buddy Chris and I were kind of stumped as to why we couldn't get the boost over 20 psi. We took a quick look at the blow off/waste-gate set up we have on the car, and we didn't see a problem.
We figured at the track, that we had just reached the limit of the turbos.

After I pulled the data I couldn't see it being the limit of the turbo's as the boost would rise very quickly and then hit 20, and stop flat.
As I looked at it I assumed that if I were reaching the limit of the turbo's the boost would reach 20 psi more slowly, and be more of a curved line.

We went back looked at the waste-gate, and found out that the boost was just overcoming the spring pressure, and needed some stiffer springs. That and the diaphragm was torn.
I ordered a new diaphragm for $16, and found a couple stiffer springs. I should have it in this weekend, and hopefully I get at least one more chance to take her to the track.
We are going to try to put a little more boost to the motor with out blowing it up. (Knock on wood)
I'm really hoping to get her to run a 10 something before the year is up.

Bob

daily400

Hey buddy note sure of your complete setup but by adding harder springs can do more damage then good. What are you using for a boost contrôlée?? I hope it's not a manual. B: i would suggest waste gate pressure on each one should b 1 bar. C: double check your boost controler setup. There is a ton of ways they can b hooked up some for the slower better controlled boost and others very aggressive. D: the lines for your waste(vac/boost) should b either stainless or a fuel vapor hose due to the hardness and resistance to expansion/coplase

daily400

Sorry one last thing when u do a pull let's say 3rd does your car almost die if so shim your bov's about 1/8 inch

rdm20fan

No, the car doesn't die. It pulls very hard. I'm trying to increase the boost.
The car doesn't have wastegates All the exhaust goes through the turbo. I regulate boost pressure with a wastgate which we converted to the cold side to act as a blow-off (Pop it style) valve.
I'm increasing the pressure on the valve to not let the boost out.

This is not a daily driven car.

daily400

That doesn't sound safe at all. If you had wastegates you wouldn't have to buy harder springs. All you would need is a 1bar spring and a boost controler at that point you could control boost up to whatever your car can hold..

daily400

And your set up is over running your turbos

rdm20fan

Thanks daily 400.
I have had this conversation multiple times.
I understand.
I might over spool my turbos.
I might have a set up that won't work.
I might blow it up do to a surge of boost into each gear.
Or I might have the quickest, and fastest SC400
I've been running this set up for 3 years now.
So,far the car has only gotten quicker n faster. The turbos have so far been responding fine. They are XS Power turbos. I think they were about $360 each. For the cost I can not complain with the performance.
There is more then 1 way to skin a cat.
No waste gates, and a large waste-gate converted to be used as a blow off is the way this cat is getting skinned.
I'm not applying any manifold pressure/vacuum to the top of the diaphragm yet. this is the reason I'm putting stronger springs in the valve.

rdm20fan

Hey guys, I haven't posted in almost a year.

I did get the boost above 20psi. But started running into a problem of pushing out coolant above that point. I think I comprised the head gasket when I changed out the head studs.
Over the winter I'm going to take the heads off and look into correcting the issue. I think I'm going to O-ring the heads to help ensure I don't have the issue in the future.

The SC ended up running multiple passes in the low 11's with a best E.T of 11.01 although I was very excited with the time, I was so close to running a 10, but for now she is an 11 second car, not a ten
The best mph was 133 with multiple 130+ mph trap speeds.

I did break the supra auto Torsen diff. I guess the hard launches with a 10" slick, and the aggressive clutch I'm running is not easy on the differential. I'm actually surprised it handled all the abuse that it did.
I have upgraded to the 6-speed manual differential. Those things aren't cheap. My old gear was a 3.76 and the 6-speed has a 3.26
It has been a lot different getting the car to leave with the taller gear. I need more practice. I'm afraid of breaking the new diff, so I haven't done a lot of pulls on it. I'm waiting to upgrade the center section.
I have noticed some stress cracks starting on the driveshaft. It hasn't broken, but I need to look into getting a new one made.


My buddy Chris and I decided to paint the car, and make her look pretty.
That has basically been the project of this summer. She is getting close, but not done yet.
I will try and post some photos of the progress of the paint n body work.

rdm20fan

Pics of the broken diff.

rdm20fan

Photos of the paint n bodywork in progress.

BS ISF

nice and looking good! congrats on the times and that trap is looking solid!