S400 Build

[70 bird]

I may try to put a vent extension on the secondaries, the primary side is about perfect! My wot a/f is ok but I would like to see it in the low 11's I dont know about the testing on the turbos, from what I have read the tv 88mm can do 1300 hp and the 75mm s400 is rated at 1k max???

I do love the way the power comes on smooth with a turbo! I was surprized I didnt have any traction issues with my worn out drag radials!

Baron, I will try to get a video in a few weeks, right now I trying not to melt engine parts!

[GOAT8U2]

Very cool, that turbo location is growing on me, seems like the best option for the monster singles.

What is your wastegates spring rate?

Any pics of how you have the turbo mounted, plate welded to the frame etc??

I haven't found anything that would go from 5" to twin 3" for the downpipe, looks like you had that issue also.

[turbo69BIRD]

I can tell you that when you get into it hard and it makes real boost 10 psi or more its gonna shed those tires on the street.

It will not be like a N/A car though because its progressive thats whats scary all of a sudden it just breaks loose hard and your not really ready for it.

I have had seasoned 700HP N/A guuys drive my car and they are like no thanks I'm all set that thing is freaky.

They hate driving it becasue its so unprdictable to them.

Once your used to the turbo though its very predictable.

I can't wait till it makes bigger boost your gonna really love it then.

Keep it fat and safe.

I was running 98's squared in my 850 if that helps.

I was also only running 20 to 25 degress timing with 110 or 116 race fuel at 11psi.
At 14 psi it started getting too lean for my taste.

With the vent tubes I am at 72 /74's and going 10.00 for afr's under boost still.
It may be the style of my hat though.
With the 80's it was shutting off it was so rich.
With these it is stumbling all over tself.

I am going to go 70's squared tonight if the weather stays dry.

[70 bird]

Originally Posted by GOAT8U2

Very cool, that turbo location is growing on me, seems like the best option for the monster singles.

What is your wastegates spring rate?

Any pics of how you have the turbo mounted, plate welded to the frame etc??

I haven't found anything that would go from 5" to twin 3" for the downpipe, looks like you had that issue also.

I dont know the spring rate of the wastegate, Its a cheap e-bay gate it was advertised to be 11 psi?? maybe thats chinese psi??
I guess I cant complain it holds a rock steady 6 psi. up to 5500 rpm.


Heres a few pictures of the bracket...

[GOAT8U2]

Got any pics of it bolted to that plate, I am sort of confused with 6 holes being on it and the turbo having 4.

Those vent tubes sure do make it easier to get the af/r going fat while under boost. I will be doing that for sure with 10psi and E85.

[70 bird]

Thanks for the advice Jeff, I did some more tuning today I went down an industrial drive that had a little dirt on the road and the back end started sliding around a bit! Its kinda like black ice!

I put a vent tube extension on my secondary side today and it pegged my wideband full rich. after a few jet changes I ended up at 87 on the secondary with a 35 squirter, this got me around 11.5 a/f. Sounds good but after a few runs my readings were inconsistant?? Its seemed when got into it the a/f would be around 10 then slowly lean to around 12 after 5000rpm. Not too bad but I still need to keep an eye on it when I turn up the boost.

After about 40 miles of playing I developed a misfire, but my wideband readings were still good. wtf?? after pulling the plugs finding nothing wrong and replacing the plug wires I pulled the driver side valve cover and found a broken rocker-lock on #1 intake, funny, it didnt make any noise and the rocker arm and pushrod were sitting there with no damage go figure!! Time to buy some more parts!

[70 bird]

Originally Posted by GOAT8U2

Got any pics of it bolted to that plate, I am sort of confused with 6 holes being on it and the turbo having 4.

Those vent tubes sure do make it easier to get the af/r going fat while under boost. I will be doing that for sure with 10psi and E85.

The bracket bolts to my merge pipe which supports the turbo. These are the best pictures I could find. Many of the parts I used were stuff I had laying around the garage that explains the "extra holes"

[turbo69BIRD]

Your vet tube extension sounds like its either in an area of turbulence or its loose in the hole and letting off boost pressure maybe?

Those are the ony things I can think of that would cause it to fluctuate.

sucks about the lock but at least you found it.

My vent tubes come pretty far dwon into the inlet tube. Its rock solid but it picks up so much signal I am down to 72 jets from 98's Its still fat under boost to the tune of 10.0 Almost doesn't seem right.

WIll be great for light cruising and fuel milage if I can get it cleaned up though.

[Bruce Wilkie]

You know all the sensitivity of blow thru carbs really has me considering old school draw through. As long as the fuel supply keeps up and the carb is sized and jetted it seems far less sensitive. I never had issues on my old vair with a 350 holley and E flow compressor kit. (sure had way better response than the late 70's early 80's factory draw thru setups or the the original F flow and sidedraft carter). Firechicken on PY board has a near stock 400 with 2 Turbo TA turbos and qjets running well into the 10's under 5500 rpm and all his factory options close to 4000 lb race weight IIRC. How bad can it be?

I'm going to have to really think this out some more before I order my turbos.

Sorry to jack the thread!

[70 bird]

I dont know much about draw thru's. What happens if you let off the throttle under boost?? Do they use a bov??

The blow thru carb is not as bad as it sounds. On my capri I never even had to remove the hat last summer, once they are set up they dont have many problems. With 2 days of tuning I have decent driveability for under $300 on my bird. Just takes some work!

[turbo69BIRD]

I know a ton of guys who ran them on boats in the eighties and absolutely have nothing good to say about them and these were banks kits.

Blow thru is the way to go. IMHO

[70 bird]

Damn,I just got the carb dialed in and the car is starting to push some coolant from the overflow! If I go out and drive like a normal person its fine, but If I go out and beat on it and pull into a parking lot to check things over I have some bubbles/foam coming out of the overflow. I think I hurt it last fall with the blower, I reprogramed the ignition box on my pc and when I reinstalled it I forgot to plug in the map sensor hose! I put down about a half gallon of coolant one time. Once I figured out what was going on everything was fine for a few months.......till now! I ordered some 1016's I will be back in action in a week or two.

[turbo69BIRD]

YUP sounds like headgaskets to me too.

If you have cometics sometimes you can retorque and get rid of that I have had it happen and re-torqued and it worked.

If you run it with the cap off do you get bubbles?

If you fire it cold and run it for only a few seconds does your hose get hard as a rock?
if so its most likely compression getting in the radiator

[70 bird]

I tried to re-torque the fel pro's last night, didnt work.

At idle its not building any pressure it seems to be under heavy load(boost). Its not too bad now but Im sure it will end up in the oil if I keep driving it.

[Ford Engineer]

Fix the head gaskets, LOL!

Tom Vaught

[70 bird]

Originally Posted by Ford Engineer

Fix the head gaskets, LOL!

Tom Vaught

Hope to be up and running by the weekend. With new gaskets.

[turbo69BIRD]

Very efficient!

[flynbrian]

Dang, At least it was your turbo car that did this! My N/A 95' Z28 Camaro just blew its head gaskets all on its own....

I pulled mine apart and found the number #7 cylinder's firing ring literally looking like it rusted away. Cylinder #5 had about 3" water/antifreeze standing in the cylinder. Which was odd since it looked fine around the firing ring etc. The firing ring in #7 was broke all the way over to a head bolt then it cracked on the other side of the head bolt to the main water jacket port in the head. It managed to suck coolant from like a inch+ away.

Mine pressurized the coolant with the cap on and steamed out the exhaust. Pull the radiator cap and it bubbled lightly and no more steam.

I sent the LT-1 Aluminum cylinder heads to my Trusted Engine builder, He found they were not warped. The #7 hole had a divot next to it that took .007" on the milling machine to get the head to clean up all the way. They also found that a few intake valves were not sealing worth a crap. It got the total treatment and now the heads appear as brand new. I'm eager to put it back together...Ron my builder told me that the car should scream compared to how it was before.
And I trust him...the car just a few hundred miles before the gasket went ran 13.89 @100 mph with a messed up transmission...The guy I bought the car from had the tranny redone and the wrong convertor was installed and it smoked the front pump...So now with the HOT brand new 4L60E and the fresh top-end I am eager to see whats next for a E.T.

Let me add that Thank God your working on a 70' F-Body.....The 95' F-body is a total nightmare to work on and you need to have a super back to bend over & reach under the firewall to work on it. I hate working on my 95' Also I noticed that the head bolts all felt different when they were coming out....some came loose rather easy and others were a bit of a bear. I heard that's normal with a 130,000 mile aluminum head/cast iron block motor.

[turbo69BIRD]

Flyin How many damn cars do you own?????
your worse than I am.

[70 bird]

I pulled the heads this morning #8 cylinder took a dump. The good news is I didnt see any other damage. I was able to pull the heads and studs without having to remove the turbo or downpipe.