What turbo should I buy? Options

[andys]

Just a quick comment; I'd look to keeping the boost in the 5-7psi range. More boost makes manging the heat more difficult in an air cooled motor without an intercooler. The water injection as suggested for this application is worth looking into, IMO. Besides, you really won't notice the second 5 psi nearly as much as the first 5psi.

Andys

[turnaround89]

After some pm's i had with RJMII, i am gonna look into and aftermarket efi system, instead of running carbs. The carbs that i already bought for the 914 will go onto my baja bug, ill need different intakes, but at least they don't go to waste that way. Or maybe even sell them and put that money into the 914 efi + turbo setup.

Megasquirt may be the way i will go. I got a little more reading about microsquirt to do, but i think megasquirt might be the best choice.

If i go efi, the turbo will go from the original idea of draw-through to a blow through setup. That way i could run the intercooler and keep temps lower.

Im mainly in the stage right now of deciding on efi or carbs. Sooner or later my 914 will have a turbo. I have to wait for a bonus i get from work to start purchasing parts. Woodman's is an awesome part-time job, grocery store in the midwest area, mainly Wisconsin and northern Illinois.

Sorry for flipping out, just don't like advice of giving up at all. Ottox914 and chairliew, my apologies, you are only trying to help. thank you!

[iamchappy]

Just a quick comment; I'd look to keeping the boost in the 5-7psi range. More boost makes manging the heat more difficult in an air cooled motor without an intercooler. The water injection as suggested for this application is worth looking into, IMO. Besides, you really won't notice the second 5 psi nearly as much as the first 5psi.

Andys

I certainly have not found that true, even 8 is a big jump from 5, 10 is a leap and 14 is a plunge!

[turnaround89]

10, probably won't happen on my car, maybe put it there once to see what will happen. 7.5 to 8, would be what im shooting for.

[RJMII]

Just a quick comment; I'd look to keeping the boost in the 5-7psi range. More boost makes manging the heat more difficult in an air cooled motor without an intercooler. The water injection as suggested for this application is worth looking into, IMO. Besides, you really won't notice the second 5 psi nearly as much as the first 5psi.

Andys

I certainly have not found that true, even 8 is a big jump from 5, 10 is a leap and 14 is a plunge!

(IMG:style_emoticons/default/agree.gif)

[ottox914]

Just a quick comment; I'd look to keeping the boost in the 5-7psi range. More boost makes manging the heat more difficult in an air cooled motor without an intercooler. The water injection as suggested for this application is worth looking into, IMO. Besides, you really won't notice the second 5 psi nearly as much as the first 5psi.

Andys

I certainly have not found that true, even 8 is a big jump from 5, 10 is a leap and 14 is a plunge!

I'm with Chappy on this one. The first five was fun, 5-10 was more fun, and when the motor is built up, we'll see how 10-15 feels...

From "street turbocharging" by Warner, page 95.

1-5psi no intercooler or water injection
5-12psi intercooler only
12> intercooler and water injection.

Chappy has come up with an elegant solution to getting air thru an intercooler used in a mid engine application. My intercooler is the standard unit off a wrx, and has a metal plenum below it holding a 1000 cfm fan to pull air thru the intercooler across the whole core. On a 90 degree day, I'd have intake temps around 30 degrees over ambient. On cooler days, the increase was 10-20 degrees. After an hour or so at highway speeds, the IC would heat soak, even with the fan on, and temps would continue to rise to maybe 30-40 above ambient, but at highway speeds at steady throttle there was no boost involved, so slightly elevated temps were not a concern. I was considering adding water injection, and may still do so, but for now plans are for the built motor and a new plenum that seals better, and has 2- 1100 cfm puller fans in it. I'll try the new 2 fan system before getting much farther into the WI install. Of course, this will vary with the type of motor, compression ratio, fuel used, amount of boost, and a 100 other things. Best to walk before you run.

[nein14]

After some pm's i had with RJMII, i am gonna look into and aftermarket efi system, instead of running carbs. The carbs that i already bought for the 914 will go onto my baja bug, ill need different intakes, but at least they don't go to waste that way. Or maybe even sell them and put that money into the 914 efi + turbo setup.

Megasquirt may be the way i will go. I got a little more reading about microsquirt to do, but i think megasquirt might be the best choice.

If i go efi, the turbo will go from the original idea of draw-through to a blow through setup. That way i could run the intercooler and keep temps lower.

Im mainly in the stage right now of deciding on efi or carbs. Sooner or later my 914 will have a turbo. I have to wait for a bonus i get from work to start purchasing parts. Woodman's is an awesome part-time job, grocery store in the midwest area, mainly Wisconsin and northern Illinois.

Sorry for flipping out, just don't like advice of giving up at all. Ottox914 and chairliew, my apologies, you are only trying to help. thank you!

Before you commit to an EFI injection system which is very $$$, by the time you done with your conversion you will be in the cost range of doing a 3.0 /6 911 motor.

Another option is to use Bosch CIS injection which is what my Turbo is using, which is the same design principle as the Porsche 930 onlty a 4 cyl. version.

Very very reliable, and a cost effective conversion. I run 10lbs. of boost on the street on premium and have run 14 lbs. on 100 octane on the track with the Caroll Water Injection system I have and the car does not have a intercooler.

This can also has a 3 qt. accusump and a front mount oil cooler and has been running this set up since 2002 thats 7 years !!!!!!
Very very reliable and can be driven as a daily driver! (IMG:style_emoticons/default/driving.gif)

Geat a copy of Excellence magazine June 02' there is a 4 page article on the car (IMG:style_emoticons/default/smile.gif)

Good luck with your project keep me posted on your progress.

[Dr Evil]

We should have a separate turbo 914 forum just for this stuff. There is so much. Thanks for sharing (IMG:style_emoticons/default/smile.gif)

[Dr Evil]

Some pics I poached (IMG:style_emoticons/default/smile.gif)

[andys]

Just a quick comment; I'd look to keeping the boost in the 5-7psi range. More boost makes manging the heat more difficult in an air cooled motor without an intercooler. The water injection as suggested for this application is worth looking into, IMO. Besides, you really won't notice the second 5 psi nearly as much as the first 5psi.

Andys

I certainly have not found that true, even 8 is a big jump from 5, 10 is a leap and 14 is a plunge!

You guys are taking my comment all wrong; that's probably my fault (IMG:style_emoticons/default/rolleyes.gif)
From nothing to 5 psi is pretty dramatic. A 5 psi delta is another matter.

Built my first tubo conversion in '69 using a '63 Olds Jetfire turbo setup that employed alcohol injection, and several more after that including a 914-4. No one made any of the great controls we have today, so we made our own. I'm not very current anymore. (IMG:style_emoticons/default/sad.gif)

Andys

[ottox914]

We should have a separate turbo 914 forum just for this stuff. There is so much. Thanks for sharing (IMG:style_emoticons/default/smile.gif)

Ask and you shall receive: http://forums.aircooledtechnology.com/forumdisplay.php?f=34

[RJMII]

We should have a separate turbo 914 forum just for this stuff. There is so much. Thanks for sharing (IMG:style_emoticons/default/smile.gif)

Ask and you shall receive: http://forums.aircooledtechnology.com/forumdisplay.php?f=34

What about those of us with watercooled turbo teeners?

[iamchappy]

there used to be a site here.

http://www.914turbo.com/

[rusty914]

(IMG:style_emoticons/default/popcorn[1].gif)

[charliew]

nein14 seems to have a very good cost effective solution already worked out. His setup would be a very good place to start. I don't know if they are any good but a lot of guys bought tt suby motors and have the turbos laying around. One is larger than the other so it seems one of them might work on a 1.8 or 2.0 to get started. Of course the optimum would be a new high tech. one it would for sure spool faster.

[RJMII]

What that gold thing does. =o)

I went and took my turbo apart to take some pics for you. This should help some with basic questions understand a little bit more.

[biggy72]

I haven't had a chance to read through all of the links, but I like the book maximum boost by Corky Bell for a good overall introduction to turbos. For most people they could probably design the whole system off of the book, but it can also get much more involved as well.

What kind of compression ratios are you guys running with those boost numbers? Doesn't Jake have a turbo cam? If so is anyone running it?

I could probably find this if I looked, but does Jake have any volumetric efficiency numbers for his head configurations? I've got a pretty simple spreadsheet I made to figure out estimated numbers on boost and hp that I made last year at school. It builds a chart that can then be placed on a turbine or compressor map to figure out which turbo fits the best with the given engine.

You guys are worried about 10 psi? This guy is running well over 30 and his car is real impressive: http://www.horsepowerconnection.com/

[FourBlades]

Go big:



This Porsche owner has the right idea about impeller size:



This is a nice set up (but a little small) that might fit a 914:



John

[turnaround89]

Dr. Evil - you just nailed exactly what my exhaust was going to look like. Thats exactly what i was shooting to make. I will have to cut through the floor of the trunk, but thats no big deal.

[ONTHEGRIND]

What that gold thing does. =o)

I went and took my turbo apart to take some pics for you. This should help some with basic questions understand a little bit more.

That is for the waste gate a C Clip should hold that on there.. Some hot rodder's weld it so it doesnt open for max boost.. When the Booost reaches its pressure the wastegate opens waisting boost back into the exhaust system..