turbo 200 build

pmuller9":1n54x5p5 said:
Did you run any boost during the short trip?

I did get it into boost briefly - about 4psi - not long enough to tell how the car runs.
My tuning session did not go well - the guy that's helping me tune the car is on a tight schedule so we didn't have a lot of time. Right off the bat my fuel pressure readings on the computer were inaccurate (showing 5psi). Tried switching out the fuel pressure sensor with one we know works and the psi registered 153psi which we decided was not correct either. That was problem #1. Problem #2: at idle around 800rpm I have no vacuum - I was getting about 1psi in the manifold. If I put the rpm's at 1100, I have vacuum. I disconnected the tubing between the turbo and the throttle body to see if that would change anything and that made the idle much worse. I'm assuming I have a vacuum leak - I have several things I'm going to check, but would like any input/advice.
 
On our race turbo engines where there was lots of plumbing and "V" clamps, I would plug the exhaust outlet and also make a plug for the intercooler inlet with a fitting that would allow me to attach my leak down tester so I could regulate the air pressure going into the system.
This way the exhaust system, engine and intake system is pressurized and you can find all leaks.
Keep the pressure under 20 psi.

I'm not expecting any major leaks since there was 1 psi at 800 rpm (This is not from the turbo) but it is good to check for all leaks anyway.

Another thing is to do a compression check just to be sure all the valves are closing on the seats and not being held open by a lifter.
 
67Straightsix":34sey5yf said:
pmuller9":34sey5yf said:
Did you run any boost during the short trip?

I did get it into boost briefly - about 4psi - not long enough to tell how the car runs.
My tuning session did not go well - the guy that's helping me tune the car is on a tight schedule so we didn't have a lot of time. Right off the bat my fuel pressure readings on the computer were inaccurate (showing 5psi). Tried switching out the fuel pressure sensor with one we know works and the psi registered 153psi which we decided was not correct either. That was problem #1. Problem #2: at idle around 800rpm I have no vacuum - I was getting about 1psi in the manifold. If I put the rpm's at 1100, I have vacuum. I disconnected the tubing between the turbo and the throttle body to see if that would change anything and that made the idle much worse. I'm assuming I have a vacuum leak - I have several things I'm going to check, but would like any input/advice.
Sounds fairly typical of a big cam generating more vacuum at higher rpm above a low idle. What does sound off is the MAP sensor scaling values, which sound typical of a mismatch in programming the sensor type you're running. I'd recheck and confirm what bar MAP sensor you're running then verify the tune file has it saved correctly. You can then confirm its reading correctly at key on engine off that it reads very close to the current baro reading wherever you live. For me at sea level, it's always right at 100kpa
 
I checked for vacuum leaks and checked compression - no vacuum leaks and compression is 150psi. I think guhfluh might be onto something with the map sensor, but I'm not sure how because when I originally tuned the engine we had the same sensors on it (I haven't changed anything - and the map sensor is the correct one) Back then the fuel tables looked smooth and consistent and now they're not. The computer acts like it's getting false information and is trying to correct an issue that doesn't exist. My tuner guy is in the process of moving his shop and has been unavailable - so I'm taking a crash course on learning how to tune :banghead: I'm still trying to pin point exactly what my problem is - no one I've talked to has been able to figure it out. As always thanks for all the input and suggestions - I couldn't have gotten this far without it (y)
 
Checking for the correct sensor scaling is pretty easy. You just connect to the ECU with your laptop or touchscreen and pull up the current sensor readings. With the ECU powered up, but the engine not running, compare the current barometric reading for your area at that time (Google on a phone works quick and easy) to what the ECU is displaying for a MAP reading(the MAP should be displayed in kpa). If the two are off more than 5-10kpa max, then you have a problem.
 
The 150 psi compression seems very high for a cam with a 300 degree intake lobe duration and an 8:1 compression ratio which may indicate that the cam timing is way off.
The cam card shows the LSA as 115 degrees which puts the intake lobe center at 111 degrees ATDC for a 4 degree advance.

Where did you set the intake lobe center when you installed the cam?
 
pmuller9":3go0yviv said:
The 150 psi compression seems very high for a cam with a 300 degree intake lobe duration and an 8:1 compression ratio which may indicate that the cam timing is way off.
The cam card shows the LSA as 115 degrees which puts the intake lobe center at 111 degrees ATDC for a 4 degree advance.

Where did you set the intake lobe center when you installed the cam?

Good question, and the reason I have not responded is because if that's the case... :arg: :banghead: :banghead: :banghead: :banghead: :banghead: :banghead:
I think I set it correctly at 4 degrees, but your question makes a lot of sense so now I'm doubting myself :unsure:

The car starts right up and idles about 800rpm - it runs until it warms up then the car starts running too rich and dies. I'm still waiting to have my computer guy take a look at it. Very frustrated at the moment and am starting a 7 day work week for three months so I have to walk away from the build for awhile. But don't worry, I will get back to it and get this all figured out.
 
67Straightsix":2dousqtq said:
pmuller9":2dousqtq said:
The 150 psi compression seems very high for a cam with a 300 degree intake lobe duration and an 8:1 compression ratio which may indicate that the cam timing is way off.
The cam card shows the LSA as 115 degrees which puts the intake lobe center at 111 degrees ATDC for a 4 degree advance.

Where did you set the intake lobe center when you installed the cam?

Good question, and the reason I have not responded is because if that's the case... :arg: :banghead: :banghead: :banghead: :banghead: :banghead: :banghead:
I think I set it correctly at 4 degrees, but your question makes a lot of sense so now I'm doubting myself :unsure:

The car starts right up and idles about 800rpm - it runs until it warms up then the car starts running too rich and dies. I'm still waiting to have my computer guy take a look at it. Very frustrated at the moment and am starting a 7 day work week for three months so I have to walk away from the build for awhile. But don't worry, I will get back to it and get this all figured out.




would loved to have gone this route with my turbo build. but ultimately to much money so ill be fine with mine for now.
gtxz4xG.jpg
going to throw a rb25 in it later but when i turn up the boost 15 psi should be quite fun
 
End of year update: we put a new tune on the car and it purrs, starts right up, and the fuel map is nice and smooth now. Been working on finishing the rest of the car - have to polish and wax and put a few finishing touches on the interior. I'm still searching for original window trim to finish out the windows (If at all possible keep your original window trim for the windshield and back window - the new stuff is absolute crap)

Because of the cam, the aluminum flywheel and highway gearing I have to get the rpms up to get the car rolling - once the car is moving it is FUN - the acceleration is awesome and I still only have 4psi of boost (after I put more miles on the car, I'll start increasing the boost). I'm going to install a true trac with 373 gears which will help get the car off the line nicely. I think the lower gears will suit the engine better.

Been following your build (thatblue_67stang) - good job! Sometimes I wish I'd taken your route :D






uJUb05.jpg

zjpAsf.jpg

mUhbTl.jpg
 
:beer: Car looks great.
I could not drive my wife's escort without stalling it four or five times (no torque ,small flywheel) She had no problem ,she was used to it...The gear change will help.
What rpm does it quit pulling...If you have dared it yet ?
 
drag-200stang":2sb4zlms said:
:beer: Car looks great.

Thank you. My wife gets the credit for the paint job turning as good as it did. She put in a couple hundred hours block and wet sanding (more than I was willing to do) She also laid out the tape for the stripes because "apparently" mine weren't straight :unsure:

The rpm's - I've had it up to 4,300 the car pulls hard at that point - I don't want to push it too hard yet until I sort out a few things. I think P.Muller is correct - the turbo is too small for the cam. I'm going to drive the car for awhile and figure out which one I want to change. My plan for the car changed during mid-stream and ended up going more performance than I'd originally planned. So I need to decide what the primary use of the car is going to be and adjust accordingly.
 
The turbo was sized to make power from 2000 to 5500 rpm with a 6000 rpm limit.
With the correct cam it would be blast to drive on the street.
 
Just my 2 cents, I think the thing is going to run really well from 3200- 5500 rpm. leave the cam in it until you get it tuned and give it a fair shake. My head was similar to your head, the cam was close (113 LC) to the same although my engine had more cubes it ran very well from 2800 to 5200 rpm's. I did find that the more boost I gave it, the better manners the engine had, turbo spooled quicker, power came in earlier and the car just ran better. I ran 18lbs on 91 octane pump gas 20 psi with Octane booster. . You have the advantage of EFI so timing and fuel control your setup will be much better. You have a 350 whp pump gas setup when tuned with more boost.
 
67Straightsix":w0wk1fun said:
End of year update: we put a new tune on the car and it purrs, starts right up, and the fuel map is nice and smooth now. Been working on finishing the rest of the car - have to polish and wax and put a few finishing touches on the interior. I'm still searching for original window trim to finish out the windows (If at all possible keep your original window trim for the windshield and back window - the new stuff is absolute crap)

Because of the cam, the aluminum flywheel and highway gearing I have to get the rpms up to get the car rolling - once the car is moving it is FUN - the acceleration is awesome and I still only have 4psi of boost (after I put more miles on the car, I'll start increasing the boost). I'm going to install a true trac with 373 gears which will help get the car off the line nicely. I think the lower gears will suit the engine better.

Been following your build (thatblue_67stang) - good job! Sometimes I wish I'd taken your route :D






uJUb05.jpg

zjpAsf.jpg

mUhbTl.jpg


thanks that means alot. as of this winter im throwing a 8.8 in with 3.73 gear. im also widebodying it and slappinng some 315s on the rear. then i hope to turn it up to about 10psi. it should be a beast. here is a render of what its going to look like. i am also making my own k member and custom suspension for my car with custom piece i have designed myself to hold a fully adjustable upper control arm to the stock mounting holes

9CYoW0o.jpg

c0lRSLU.jpg
 
thatblue_67stang":ucsjghhu said:
67Straightsix":ucsjghhu said:
End of year update: we put a new tune on the car and it purrs, starts right up, and the fuel map is nice and smooth now. Been working on finishing the rest of the car - have to polish and wax and put a few finishing touches on the interior. I'm still searching for original window trim to finish out the windows (If at all possible keep your original window trim for the windshield and back window - the new stuff is absolute crap)

Because of the cam, the aluminum flywheel and highway gearing I have to get the rpms up to get the car rolling - once the car is moving it is FUN - the acceleration is awesome and I still only have 4psi of boost (after I put more miles on the car, I'll start increasing the boost). I'm going to install a true trac with 373 gears which will help get the car off the line nicely. I think the lower gears will suit the engine better.

Been following your build (thatblue_67stang) - good job! Sometimes I wish I'd taken your route :D






uJUb05.jpg

zjpAsf.jpg

mUhbTl.jpg


thanks that means alot. as of this winter im throwing a 8.8 in with 3.73 gear. im also widebodying it and slappinng some 315s on the rear. then i hope to turn it up to about 10psi. it should be a beast. here is a render of what its going to look like. i am also making my own k member and custom suspension for my car with custom piece i have designed myself to hold a fully adjustable upper control arm to the stock mounting holes

9CYoW0o.jpg

c0lRSLU.jpg
 
fast64ranchero":1bdd34up said:
I'm confused, are thatbluestang and 67straightsix the same or is Thatbluestang hijacking this thread?

Not the same person and havent hijacked this thread. Thanks for your concern though.
 
pmuller9":1dszgsj6 said:
67Straightsix
Any Updates?
I know the weather has prevented many from doing very much.
Yes, the rain has put a damper (haha) on things. Since my last post I've taken it out for three 40 mile test drives to work out the kinks. My impressions so far; from idle to 1500 rpm it drives like a dog - from 1800rpm to about 2800 it pulls very strong - at 2800 the car absolutely puts you in your seat and I'm being very light-footed on the throttle. I haven't pushed it past 4000rpm yet. The rear end has 2.79 gear ratio which is wrong for my engine and transmission - I'm currently building a more suitable rear end. Second gear is good until 45mph - can go 55 easily in third - and can't get into 5th until 80mph. At 60mph in 4th gear I'm turning 2000rpm. On one of my test drives, we went up a mountain road - the car loved the hills - pulling the hills the engine did much better than in the flats - I think a lower gear ratio will help the car. So far I'm happy with how the car drives - I'm new at driving a turbo car so I'm still getting used to the way it delivers power as compared to a non-turbo car. I've got the boost set at 10psi.

The ar ratio at idle is about 13/1 and driving it's between 13.5 and 12 - I'm wondering if that's a fuel good ratio? I still have more tuning to do. My fan controller has not been reliable - the good news is that even without the fan the car stays below 209 degrees in traffic and reads 185 while driving.

pmuller9 - I concede that for driving around town a milder cam would be better. But for now I just want to drive the damn car and I live 40 miles from Thunder Hill! (a really fun road course)
 
Back
Top