TURBO DRAW THROUGH 74X92 (1968CC)

[newbyone]

New to STF. So Hello!
Just finished building. Here comes the specs.
1969 Bug Fiberglass frontend
74x92 = 1968cc
40x35.5 heads dual hi rev. mildly ported.
engle 120cam
solid shaft rockers 1-1
valves at finger spin (chromoly pushrods)
Holley blue pump regulated at 3.5 lbs
holley 600cfm vacuum secondary. boost referenced (draw through)
Rajay EF60 (may be too big)
Ignition at 24 009 locked. (yes I am Aware theres better available.) (not looking to get beatup

Just a garage project with my kids.

Here is my question . Only getting 75 percent throttle. How does this directly impact boost. please be specific. also feedback on turbo sizing would be helpful.

Thank you in advance for your replies.

[Clonebug]

Since it is a Holley and the secondaries work off vacuum.....with only 75% throw you might not get that zero Atmosphere to make the secondaries open. I'm just guessing with my own common sense thought though.

I have no experience with draw through so I can't give much input on turbo sizing.

With my blow through I judge a turbo by the inlet and outlet impeller size. With my 1679 it performs excellent with impellers in the 1 5/8 inch to max 2 inch diameter. That gives me full boost by 3800 rpm.
The only time it is slow to react is when in fourth gear at 50 mph and you give it full throttle. But if you drive it that way you aren't doing it right.
For aggressive driving you want the rpm's at 3000-3500 and then it's insta-boost to 22 lbs.

If a draw through acts the same way then an inlet of 2-2 1/4 inches on both sides for you would probably give good results. Although it depends on what your max boost level is going to be.
With lower boost pressures you could downsize the turbo for quicker response but less top end power.

Don't be shy......post some pics or start a build thread......we all love turbo action whether building, boosting or fixing broken parts.......

[newbyone]

I am trying to add some pictures but it keeps saying file too large.
Maybe some guidance. I'm using an iPhone

[Clonebug]

Pictures can only be 800X600 in size.

I upload to Photobucket and then paste the [IMG] from there.
I upload all my pics to Photobucket at 800X600 and that way all are good for most forum posts.

[newbyone]

Ok thank you. I will upload some photos tonight. This car was a Baja no motor sitting across the street. The bug had been sitting for 10 years.

Replaced all brakes and converted to wide 5 brake drums.
New wheels and tires.
Painted it in the garage.
I installed a Close ratio rhino case IRS transmission.
Built the 1968cc motor.
'Its funny cause I told the wife my budget was 3000.00 LOL LOL LOL (had to or else I would not have been able to buy it)

[madmike]

Welkome,,,Your fuel pressure is to low for a Holley try 7lbs.
turbos don't care for 'close ratios' they prefer wide ratio geras

[Clonebug]

Turbos definitely like the long pulls when boost is built.

[newbyone]

Adjusted the fuel pressure. 7 lbs running.
Thanks for the tip! Working on the photo bucket thing. Will get some pictures up soon!

[newbyone]

This is where it started.

[newbyone]

After we fitted the fiberglss front end, lowered the front end, converted to wide 5

[newbyone]

Primer stage

[newbyone]

[newbyone]

Put 2" wider rear fenders . this is after clear coat. Rhino lined a front Bra.
It did have a sunroof. but that was shaved.
My thoughts were this car was ready for scrap When started so at least it will be back on the road again.

[newbyone]

And the most important part!!! I took this today. I am working on wiring and breather lines and other things.
Hope you all like the pics. Sorry if its too many!

[andy198712]

more pics the better! you really saved that bug!