Out with the old...in with the new...Britain's Racecar Development, Subaru Engine, Lotus Suspension! Time to go racing! Options

[ottox914]

You have probably researched this and thought it thru already, but since you are in the install/set-up/plumbing phase, how about preping for E85 and getting a hot tune for that corn hooch. I'd bet 400hp easy.

[J P Stein]

You have probably researched this and thought it thru already, but since you are in the install/set-up/plumbing phase, how about preping for E85 and getting a hot tune for that corn hooch. I'd bet 400hp easy.

It has been discussed. Brit is taking a conservative approach by waiting to see what breaks. The 901 is still there....tho first gear is safe cause it's in a cardboard box. As for the R&P...... (IMG:style_emoticons/default/confused24.gif)

[Britain Smith]

You have probably researched this and thought it thru already, but since you are in the install/set-up/plumbing phase, how about preping for E85 and getting a hot tune for that corn hooch. I'd bet 400hp easy.

The fuel system is prep'ed for E85, however I am going to continue using my 110octane leaded fuel for the time being. It will give the same performace gains and I have ~30gallons left over from last season. Not going to get 400hp, but hopefully close.

-Britain

[charliew]

Another thing to consider from them is their vehicle speed sensor. I have found that my engine ECU requires a vehicle speed sensor for the active valve time to function. I ordered mine today.

-Britain

My son has been hotrodding his 04 sti since he got it new. He's a mechanical Engineer with our hotrodding exposure from my and his toys. We aren't track guys though. I started with a new 02 wrx motor in a 901 tail dragger dunebuggy but decided the 914 was a better way to go. I have been planning and scrounging parts for a long time and soon may get to start the real deal. When I studied the smartcar vss a few years ago I bought one but my understanding it is only to make sure the car is in motion, it will not replace the speedo feedback. I guess you know what you are talking about on needing the two waste gates. My thought is the inlet side using two waste gates might reduce the surge of the turbo better but the pulses from each exhaust port would seem to me be better controlled after the turbo wheel rather than before to get the quickest spool time. You are doing great though and will be a very valuable source on what works at high rpm in the 914 high g suby configuration. The suby uses more oil than you will think at high rpm and high oil temps so monitor it very carefully. Now that the twin scroll exhaust is removed I would tackle the oil pan and try to get as much more capacity as you can. The oil pickup is a very critical spec on the suby motor, there is a lot of variation in the oil pan tp pickup clearance. The external oil cooler is really necessary, get a oil temp sender and good gauge. The good thing is it's a race car and you can change over heated oil pretty regularly. You also may have considered a turbo blanket I hope. Are you going to learn to do open source programming on the oem ecu also? I am anxious to see if your radiator is going to be big enough. If the boost is laggy you might want to check the exhaust back pressure at the turbo. The exhaust on my son's sti is at least 3.0 all the way with straight through muffler and no cat. Your exhaust is shorter though. I do wish you had gone with the suby tranny also.

[Britain Smith]

When I studied the smartcar vss a few years ago I bought one but my understanding it is only to make sure the car is in motion, it will not replace the speedo feedback.

Yea, that is my thought as well. However, using the Small Car Performance speedo sensor kit I should be able to get relative speed numbers and I can feed that into my AIM dash for datalogging.

I guess you know what you are talking about on needing the two waste gates. My thought is the inlet side using two waste gates might reduce the surge of the turbo better but the pulses from each exhaust port would seem to me be better controlled after the turbo wheel rather than before to get the quickest spool time.

The wastegates go before the turbo and the blow-off valve goes after the turbo. I need two wastegates because I have cylinders 1 & 3 and 2 & 4 entering the turbo separately (twin-scroll) and the two wastegates will keep the exhaust pulses independent. Wastegates control the amount of exhaust gases that go to the turbo and therefore control the boost pressure. The blow-off value is between the turbo and the throttle body to reduce surge of the turbo when the throttle is closes...the pressurize air needs somewhere to go.

You are doing great though and will be a very valuable source on what works at high rpm in the 914 high g suby configuration. The suby uses more oil than you will think at high rpm and high oil temps so monitor it very carefully. Now that the twin scroll exhaust is removed I would tackle the oil pan and try to get as much more capacity as you can. The oil pickup is a very critical spec on the suby motor, there is a lot of variation in the oil pan tp pickup clearance. The external oil cooler is really necessary, get a oil temp sender and good gauge. The good thing is it's a race car and you can change over heated oil pretty regularly.

Yes, I am also concerned about oil pick-up under the conditions that I run. I have an Accusump plumbed in and will be address the oil pan after the engine is running on the dyno.

You also may have considered a turbo blanket I hope. Are you going to learn to do open source programming on the oem ecu also? I am anxious to see if your radiator is going to be big enough. If the boost is laggy you might want to check the exhaust back pressure at the turbo. The exhaust on my son's sti is at least 3.0 all the way with straight through muffler and no cat. Your exhaust is shorter though. I do wish you had gone with the suby tranny also.

Yes, I have considered a turbo blanket or heat shield...we shall see how things go on the dyno.

Yes, I am using Open Source tuning...however this will be done at Cobb Tuning.

The exhaust is 2.5" all the way back and with the smaller turbo, it should be fine.

I might be changing to a different trans, we shall see how long the 901 lasts.

-Britain

[charliew]

When the vss was sold to me I think I remember it gives way less pulses than the suby tranny. It's not enough to run a electric speedo so my thinking was it won't run the ecu for any more than fail safe limp home avoidance.

I wouldn't start the motor without veryfying a good pickup clearance if it was mine.

My son uses open source also and I am planning on his support on mine but it isn't going to be avcs although we do have his original low miles 04 sti motor complete in my garage.

My understanding of twin scroll is the ports were put in the tubes to keep the velocity up and the pulses smoother. Smaller tubes is more velocity and putting the ports in the tubes that way means smooth pulses. We will see, thats the good thing about hot rodding and all the good ideas. I personally like to keep it as simple as possible to eliminate things breaking.

[Britain Smith]

Couple of updates while the engine is out a shop getting all the exhaust tig welded.

Some of you might have noticed in the previous picture of the radiator that the fan was mounted about an inch from the radiator. Not sure why they built it that way, but I modified the fan mounts to move it about 1/4" from the radiator. This will be much more efficient. I also had some tabs welded on for the mounts to the chassis.

(IMG:http://www.914world.com/bbs2/uploads_offsite/l7.sphotos.l3.fbcdn.net-364-1292438351.1.jpg)

Also made a bracket to hold the three master cylinder reservoirs in the front. I am mounting a Tilton brake pedal assembly and converting the clutch to a hydraulic throw-out bearing hence the need for this set-up.

(IMG:http://www.914world.com/bbs2/uploads_offsite/sphotos.ak.fbcdn.net-364-1292438352.2.jpg)

-Britain

[Britain Smith]

Made a lot of progress today. It is always nice to start bolting things back up to the car.

To mount the radiator, I had tabs welded on the core and made some nice brackets that I welded into the car. Here are the brackets:

(IMG:http://www.914world.com/bbs2/uploads_offsite/sphotos.ak.fbcdn.net-364-1292734919.1.jpg)

And with the radiator installed and radiator hoses hooked up.

(IMG:http://www.914world.com/bbs2/uploads_offsite/sphotos.ak.fbcdn.net-364-1292734920.2.jpg)

(IMG:http://www.914world.com/bbs2/uploads_offsite/sphotos.ak.fbcdn.net-364-1292734921.3.jpg)

I made the bottom radiator support elevated off the floor to ensure that if the car bottomed out or the floorboard got dented then it wouldn't destroy the radiator. The center section of the mount bar was notched to clear the tow hook hump in the sheetmetal.

(IMG:http://www.914world.com/bbs2/uploads_offsite/sphotos.ak.fbcdn.net-364-1292734922.4.jpg)

Then I worked on how I was going to fit the fuel tank. Admittedly, the fuel take was small to begin with however this was too big to fit in the small space left in the front trunk. I therefore cut off the back of the fuel tank to follow the contours of the trunk floor.

(IMG:http://www.914world.com/bbs2/uploads_offsite/sphotos.ak.fbcdn.net-364-1292734923.5.jpg)

I need to get some more aluminum, but this will be welded up and will work perfectly.

(IMG:http://www.914world.com/bbs2/uploads_offsite/sphotos.ak.fbcdn.net-364-1292734923.6.jpg)

There will eventually be a nice shroud to vent the radiator out the hood. As you can see here, everything should clear nicely. I will make a fuel tank filler neck that will extend back and enable filling the tank without having to take off the shroud.

(IMG:http://www.914world.com/bbs2/uploads_offsite/sphotos.ak.fbcdn.net-364-1292734924.7.jpg)

I also was found a nice place to mount the accusump tank. This will be activated by a manual pull release that is just long enough to route to the front.

(IMG:http://www.914world.com/bbs2/uploads_offsite/sphotos.ak.fbcdn.net-364-1292734925.8.jpg)

Ok, headed back out there now to continue working.

-Britain

[Britain Smith]

Quick question...for the fuel tank I would like to be able to determine the fuel level without having to put a stick in there. Does anyone know where I can get one of those liquid level sight tubes like the one below...preferably in aluminum and compatible with fuel.

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.specialtauto.com-364-1292735415.1.jpg)

[McMark]

There's one on this site that has a thermometer built in as well. (IMG:style_emoticons/default/sunglasses.gif)

(IMG:http://www.914world.com/bbs2/uploads_offsite/alumitank.com-419-1292738364.1.jpg)

To fab something like you pictured, just pick up some compression fittings and PVC tube from McMaster-Carr.

[0396]

Keep them coming , VERY COOL PROJECT!

[jd74914]

Don't use PVC tube. It will melt! (Edited to correct)

The sight gauge you are showing looks like it uses Legris push-to-connect fittings and probably a clear nylon tube. We use them for fluid systems at work because they are low cost and pretty reliable (leak-free) fittings.

Search push-to-connect in McMaster and pick out the desired fitting. They sell elbows with one NPT end and a push-to-connect end as shown, so you can just have 2 NPT bungs welded into your tank, screw the fittings in, and be done.

Compression fittings will also work, but I don't have a huge amount of faith in McMaster's stock. They might work fine, but when I'm shopping for compression fittings I always go to Swagelok since the prices are comparable and the Swagelok parts are significantly higher quality.

If you want to go compression fitting, the P/N for an aluminum Swagelok elbow with 1/8"NPT on one side and 1/4" compression on the other is A-400-2-2. To switch to stainless change the A with an SS. If decide to go that route their website has a selector which has all of the fittings you could ever want.

BTW: The project looks good! (IMG:style_emoticons/default/smile.gif)

[McMark]

Hmmm, I found a ton of different references to using PVC on fuel tank sight tubes.

[jd74914]

Wow...I think I read PVC this morning and thought ABS; my mistake. ABS is what you really don't want to use, though PVC is also rather brittle and can weaken in the presence of unleaded gasoline (per Cole Parmer who has a really complete/accurate chemical resistance database). IMHO the best thing to use is a clear nylon.

I edited the above to avoid any future confusion...

[ottox914]

Not like you need more projects, but...

Ducting the back of the radiator out the hood is a great idea, don't forget to duct, or seal the front of the radiator to the front of the car. It may not seem like it would make a difference, but air WILL take the path of least resistance, and around the top, bottom, and sides of your radiator will be that path. Block off those sides, bottom, and top from the first pics of your post 68. Not just with some sheets of aluminum, but include foam to make it as airtight as you can. This comes from a friend of mine who works for CAT making cooling systems for the big diesel engines, intercoolers, oil coolers for earth moving equipment. In his world, with limited ground speed, the airflow needs to be generated by fan speed, and surprising enough to me, they face bigger challenges keeping the fan noise down to meet sound regulations than they do the engine noise. So making the most of every puff of air moving toward the radiator is important, and loosing any of that cooling breeze makes the system less efficient, louder, and more expensive.

[Britain Smith]

Yep, the radiator will be completely ducted front and rear. All that will be completed after the engine runs on the dyno.

-Britain

[roadster fan]

For the fuel site gauge look at custom motorcycle suppliers these are installed on bikes all the time.

link1

ebay link

You may be able to put one together for less than these two links, but thought they may help ya.

Jim

[JRust]

I would consider modifying or adding some kind of rubber spacing on the radiator. It all looks to be hardmounted. If you get flex up front with it hard mounted your radiator won't last to long. It needs to have some mounts that allow for flex. I know that was why renegade went to a floating radiator setup. Still pretty firm in place but does move enough to allow for flex (IMG:style_emoticons/default/confused24.gif) .

Of course most of what you are doing is over my head anyway (IMG:style_emoticons/default/sad.gif) . It being the shitbox it is probably reinforced up there so flex isn't an issue. This is as close to helping as I will probably get (IMG:style_emoticons/default/blink.gif)

[Britain Smith]

The mounting points have rubber isolators, the radiator is not hard mounted.

-Britain

[plymouth37]

Nice work, I was thinking about mounting my turbo in that location for a while, looks great!