[6D6GOAT]

So..I have always wanted to run a turbo. I pulled the supercharger and dove in. this is just an fyi post for anyone that is interested.

i wanted to keep it simple and inexpensive. my plan is to use stock pontiac logs turned backwards (thank you Tom S for the manifolds off of his 69 GTO)

to my surprise the stock manifolds almost fit backwards. there was some interference with the cross member. so i decided to notch the cross member so the stock manifolds will clear. currently there is a hole in the cross member. when i pull the motor i will weld in some metal.

the drivers side easily cleared the steering box which is what i thought for sure it would hit.

once i got the manifolds in i fabbed up a bracket to support the 45lb S400 turbo. i originally wanted to make a bracket off of the passenger side head but the size and position of the turbo would make that really difficult so i decided to mount the turbo to the frame.

here is a pic...




next it was time to make the bracket and flange that the turbo would mount to and the hot side exhaust from the manifolds...




next the hot side from the manifolds to the turbo flange....that took a couple of days. alot of clearance issues with the steering linkage made for some less than ideal bends. i think when i re do it i will have both of the dump into one 3 or 3.5 inch pipe the into the turbo. another problem i had was after i welded it all up the dimensions distorted a bit because of the heat. they went in there but not nearly as easy as when i was mocking it up with tack welds..

here is a pic.. the 4 bolt flange is for the wastegate.



next is the down pipe. the S400 has a 5 inch down pipe. unfortunately there is not enough room for a 5 inch down pipe once you get around the oil filter so i ran 5 inch as far as i could then petered it down to a 4 inch with a V band clamp (God i love those things)

here is a pic of the down pipe...all pretty...nice coat of hi temp exhaust paint....and then i realized that i still have to weld in the waste gate pipe .... dough!



the cold side was pretty easy. i used the old blow off valve (which i think may be a little on the small side). then i ran the oil line..the -12 return line.



i still have to finish the exhaust. i fired it up and let it idle for a while. i still have some bugs to work out. i need to reroute some stuff (brake line on the passenger side and the fuel line) i need to get some 90 degree angle boot spark plugs to keep the wires off of the down pipe. but the ground work is laid. tomorrow i hope to finish up the exhaust and take her for a spin

[70 bird]

Looks good! clean and simple. Try to get some race gas for the maiden voyage its cheap insurance. Seems like I just talked to you a few weeks ago when you were in the planning stages, you work fast!

[b-man]

Vic,

You're definitely a man on a mission.

Nice work as usual, keep us posted on your progress with this beast.

Bart

[GOAT8U2]

Very nice, I'd love to see tons of pics like the driver header and crossover etc.

Any pics of the 4" DP into the stock exhaust?

[440GP69]

Heck Yeah thats sweet!, Since its sollidly mounted to the frame what allows movement of the pipes from engine torque?

[ponjohn]

Very nice, you work fast.

John

[twov8sandat4]

Originally Posted by 440GP69

Heck Yeah thats sweet!, Since its sollidly mounted to the frame what allows movement of the pipes from engine torque?

x2.

Do those couplers and exhaust flex section have enough give?

I love turbo projects . That is some great work you are doing there

[6D6GOAT]

thanks guys. as for working fast i kind of have to. it seems that i lose alot of sleep lying in bed trying to mentally layout and over come all the obstacles. if i dont roll up my sleeves and get out there and do it i dont sleep....also my girlfriend doesnt like to be on the back burner

as for engine flex...that is the biggest reason why i wanted to go with a turbo mounted to the passenger side head. that way all the piping would simply flex with the motor. we will see if the flex couplers are up to the task. like i mentioned earlier, when i redo the piping from the manifolds to the turbos...and i will have to redo it because when i ordered the mandrels i made sure to ordered the thick 18 gauge...i didnt want that whimpy 16 gauge stuff for my turbo build. then one night lying in bed (after i had ordered, received and cut up the tubing) i realized that i had it backwards. lol probably misordered it due to lack of sleep.

anyways, my new and improved plan (which i figured out at like 2 in the morning) is to have the drivers side come across like it does and then have the passenger side dump right into it where it currently intersects it and into a single 3.5 inch pipe and a larger 3.5 inch flex pipe right before it enters the turbo.

who knows..maybe when the motor is flexing because im hard into the boost the 18 gauge tubing may be glowing so hot it will be flexible


i ll keep you guys posted with more pics of the rest of the exhaust (even though it will be kind of a hack job)

[6D6GOAT]

Originally Posted by GOAT8U2

Very nice, I'd love to see tons of pics like the driver header and crossover etc.

Any pics of the 4" DP into the stock exhaust?

the drivers side was a breeze. the passenger side was the side that gave me a hard time..which is just the opposite of what i thought it would be.

[6D6GOAT]

well i slapped together the rest of my exhaust...it is ugly but i plan on going with a complete 3 inch exhaust in the future. i just wanted to get her on the road.

here is a pic...like i said its a hack job....i think there is even a part of a fence post in there somewhere. it goes form a single 4 inch to dual 3 inch to 2.5 at the mufflers.




after i installed it i had to take her for a drive. i took it easy because i was smelling all kinds of stuff burning off. paints, oils, anti freeze that had spilled onto the exhaust wrap. i did kind of get on it... LOOOOVE that turbo whine. i saw it hit 7 lbs of boost real fast so i let up. when the turbo is spooling down it sounded like a police siren winding down lol. i forgot to mention in the build that the air filter sticks out through the core support and is actually just an inch or so from the front grill so i think that helps in hearing the spooling.

my tune is way off. before it was even in the boost it was pig rich at 10.0 to 1 so i have to tinker with that.

one other thing i noticed is how much quieter the motor/exhaust system is compared to the headers and no turbo. it almost too quiet now

hope to get her out tomorrow and do some data logging.

[ponjohn]

Does it feel as strong as the blower?

[6D6GOAT]

Originally Posted by ponjohn

Does it feel as strong as the blower?

well, its too early to tell with my tune as off as it is.

a couple differences i have noticed are that when WOT in first gear the supercharger seemed faster. the boost came in steady and consistently. with the turbo lag in 1st gear i didnt really see that much boost when i simply floored it. it wasnt until i hit second that i saw the boost and it came in sooner and faster than with the supercharger. i guess i simply have to adjust my driving style to account for the spool up time

another weird thing is that im using the fuel map and timing from when it was supercharged. i had that map pretty close but with a turbo and approx the same boost it is pig rich from the get go. maybe it takes alot more fuel to spin the supercharger off the line than spool up a turbo??

so like i said. its early and my tune is way off. even the way it sits right now i love the turbo alot more than the SC. i love the turbo whine. i love the fact you cant even hear it when you roll up to a stop light. the car sounds like a stocker with performance mufflers. im pretty sure that my fuel economy will be alot better with the turbo...thats when i keep my foot out it of course .
when i pulled my supercharger i drove it around naturally aspirated. i think my gas mileage practically doubled just driving it around town. im assuming because there was no longer any parasitic drag from the supercharger. im hoping that i will get the same kind of mileage as i did when i was naturally aspirated with the turbo when im just out running errands.

[Overkillphil]

Hackjob my eye! Those front pipes look better than alot of the work I have seen from "professional" exhaust shops in my area.

Very cool project and nicely executed. Every time I drive a Buick GN I have an irresitable urge to start a turbo project on one of our 6x-8 headed 400 Pontiacs!

[6D6GOAT]

well just got back from some datalogging runs and some changes to the fuel maps. she is running alot better now. because the motor is basically stock (that is the next upgrade) i was shifting at 7lbs of boost. which comes fast and easy at 4000rpm.

here is some boost data from my datalogger today

1st gear 4000 rpm = 1 lbs of boost
1st gear 4800 rpm = 5.7 lbs of boost

2nd gear 3500 rpm = 4.8
2nd gear 4000 rpm = 7 lbs

3rd gear 3500 rpm = 5.5 lbs
3rd gear 4000 rpm = 7.3

just to illustrate the lag i was talking about taking off in 1 st gear vs a SC motor. at 4000 rpm in 1st gear i have hardly no boost..but the rest of the gears at 4000 rpm its 7 lbs and i have to shift.


the boost comes in alot faster and harder with the turbo.....i likey

i cant wait to get a good bottom end and really open her up to redline.

big thumbs up on the turbo. i really like it. it actually...well, let me wait until i really get stuck in traffic to verify but it seems to actually run cooler (coolant temp) despite the hotter under hood temps.

[70 bird]

The tune will take time but you will get it! The turbo is load sensitive, do you have good traction in 1st gear? I cant offer you any help with the fuel injection stuff, I think you may need a visit from Tom V. on this thread. I like the sound when it spool's up too, with my auto I just tip into the throttle and about 2600 it starts to whistle away! The car gets alot of looks, many people around here know what the sound is.

I think you may have answered your own question with the fuel curve going rich, the blower created load that is not there now and your boost is comming on sooner. Im sure there are other factors too but the bottom line is you will need to retune. You have just scratched the surface with the power that s400 will make!

[krisr]

Awesome! Would you be able to post some pics of the exhaust manifolds? That struck my curiosity centre when you said they almost worked just by swapping them around!

[David Holmberg]

Very nice Vic, Congrats!

I can't wait to see you get it sorted out, sounds like a great street car!

[Tom Vaught]

Vic, Turbos need LOAD as your test runs prove to spool properly.

Take some gear out of the driveline. Drop the rear gear ratio by a bit
like 3.55 gears. The car's street manners will improve greatly and the
extra load on the engine/turbo will allow making boost in fist gear at lower rpm.

People with lots of gears in the trans rarely put enough load on the turbo to make it work properly unless the vehicle is a semi.

Tom Vaught

[lemans411]

[QUOTE=

anyways, my new and improved plan (which i figured out at like 2 in the morning) is to have the drivers side come across like it does and then have the passenger side dump right into it where it currently intersects it and into a single 3.5 inch pipe and a larger 3.5 inch flex pipe right before it enters the turbo.

)[/QUOTE]

kinda like this? my crossover tube is 2 1/2 then it goes to 3 and bends up then it goes up to 4" AT THE BIG 90 and the pass side comes in the bottom. i found a t6 flange on ebay that went from 4" round to a t6 pretty sweet.

[440GP69]

How Much do these S400 Turbos run $ wise? Sounds like unlimited HP potential and I love the sound of turbo's spooling up to but the Install has freaked me out a little