the sawtooth build thread Options

[JRust]

LOL. I was up next in my creamsicle. Had to get to my car to go. Probably not my smartest decision to ride then. (IMG:style_emoticons/default/happy11.gif)

[DBCooper]

Just re-read this whole thread. I'd seen most but not all the parts while it was in progress, but it's SO much more impressive reading it straight through. Great job. I especially enjoyed re-reading the debate in the beginning, use that car or some other. Cool.

Excellent, Dean, in every detail. Well done and you should be proud as hell. But most important, isn't that sucker fun to drive?

[Randal]

WCR drive to Crater Lake

Your car is even nicer in person than in pictures Dean. Sure enjoyed seeing it up close at WCR.

I still can't believe how smooth your paint came out. It's just perfect.

[Eric_Shea]

I drove all the way to Boise to see this car and Dean wouldn't come out and play! (IMG:style_emoticons/default/sad.gif)

(IMG:style_emoticons/default/biggrin.gif) Next time!

[sawtooth]

I drove all the way to Boise to see this car and Dean wouldn't come out and play! (IMG:style_emoticons/default/sad.gif)

(IMG:style_emoticons/default/biggrin.gif) Next time!

You were just too fast in your cayenne, couldn't catch up to you. Sorry I couldn't make it work. Definitely next time.

[sawtooth]

WCR drive to Crater Lake

Your car is even nicer in person than in pictures Dean. Sure enjoyed seeing it up close at WCR.

I still can't believe how smooth your paint came out. It's just perfect.

Thanks Randal, it was great meeting you seeing your car on the track (IMG:style_emoticons/default/pray.gif) Hope to get to do it again next year!

[sawtooth]

Spent some time with a local tuner on the dyno. Learned a bunch about fuel and ignition maps. He did a great job on the tune, it has much crisper acceleration now, and it's getting fantastic mpg (mpg results to follow). Nothing earth shattering for hp results, but it is in line with what I was expecting. Outfront sees a drive train reduction with this motor at approx 33% Correction, should be more like 25% loss. We ended up with 153whp and 162 ft/lbs torque. That comes out to about 230chp 204chp using whp/(1-loss) = chp. According to the shop that did the cams and head work on this motor it should output 50hp over stock which is 215chp so I expected a little more on the dyno. Regardless it is running great and now I have a baseline for future improvements.

[Andyrew]

Dean,

33% loss? Maybe for an AWD vehicle thats also automatic, I personally dont believe that... The 914 trani is closer to 20% drivetrain loss.

Also 153whp x 1.33 = 203.49chp

For reference 153 x 1.2 = 183.6chp

Not trying to be a downer, but I dont think the engine is making the power you think it is.

HOWEVER that is a great looking tq line!

[sawtooth]

Dean,

33% loss? Maybe for an AWD vehicle thats also automatic, I personally dont believe that... The 914 trani is closer to 20% drivetrain loss.

Also 153whp x 1.33 = 203.49chp

For reference 153 x 1.2 = 183.6chp

Not trying to be a downer, but I dont think the engine is making the power you think it is.

HOWEVER that is a great looking tq line!

I'm not using a 901, it's a subaru trans. So front wheel drive usually is accepted to have a little more loss than rwd. But I agree after talking with outfront some more it should be in the neighborhood of 20-25% drive train loss. If you were actually calculating loss, it should be applied to chp, not whp. whp/(1-loss) = chp. So 153whp /(1.0-.25) = 204chp or 153/(1.0-.20)=191.25chp. I've seen some use the calculation you used, just doesn't make sense to me to apply the correction to the reduced amount, should be applied to the total amount. Anyway, however you calculate chp from whp, now I have a base line to work from.

[Andyrew]

I realize its not a 901 trani, but Im telling you this for comparison. You might have some loss due to the bearings, but typically the loss comes in all the extra moving parts, AKA the driveshaft, the rear diff, the rear axles. They all play apart in the drivetrain loss.

Your number should be closer the the Subaru FWD drivetrain loss.


Regardless, You have a great baseline to go up from!

[JRust]

I am a little surprised it is that low. I was expecting more also just by the feel of it around the track. Or course I was coming from the feel of my stock 2.0 (IMG:style_emoticons/default/confused24.gif) . Now we'll have to see how it does against my wimpy v8 (IMG:style_emoticons/default/evilgrin.gif) . Of course I have to get it off the stands to do that (IMG:style_emoticons/default/dry.gif) . I am sending my rear calipers off to Eric to get rebuilt. Otherwise I could be driving it tonight (IMG:style_emoticons/default/driving.gif)

[sawtooth]

I am a little surprised it is that low. I was expecting more also just by the feel of it around the track. Or course I was coming from the feel of my stock 2.0 (IMG:style_emoticons/default/confused24.gif) . Now we'll have to see how it does against my wimpy v8 (IMG:style_emoticons/default/evilgrin.gif) . Of course I have to get it off the stands to do that (IMG:style_emoticons/default/dry.gif) . I am sending my rear calipers off to Eric to get rebuilt. Otherwise I could be driving it tonight (IMG:style_emoticons/default/driving.gif)

And it is noticeably more responsive now with the tune than it was on the track at WCR. IMHO I think the hp rating is deceptive, it's the way the torque (although not close v8, but much lighter) comes on quick and remains that makes it pull pretty decent.

[uncle smokey]

Man, I just read the whole thread and all I can say is WOW! That thing is friggin awesome.

[Mikey914]

This car is truely impressive!

[J P Stein]

I've always used 15% driveline loss. That may seem conservative but I never got into the big hp numbers game. Nice torque regardless. Torque is what counts (IMO) unless you're running at Daytona. (IMG:style_emoticons/default/biggrin.gif)

[charliew]

I think going by the numbers others have achieved with midly hopped up na 2.5 subys that 200-210 is reasonable at the crank. Just keep using the same dyno and keep all the tuning printouts for reference and you are good to go. It will be a good reliable package that will leak far less oil and when it warms up it will keep the power unlike a air cooled motor. A good equal length header is about all I could think of that might help as it is. Also make sure the fuel is always the same. Also you might try removing the air filter on one of the pulls to see if the intake is restricted next time. The numbers do fall off a little early for better cams though. I would want the revs to go to at least 6500 on a na motor.
The shop that did the work surely doesn't think it should quit at 5700? Sorry actually 5800 I think.

[sawtooth]

I think going by the numbers others have achieved with midly hopped up na 2.5 subys that 200-210 is reasonable at the crank. Just keep using the same dyno and keep all the tuning printouts for reference and you are good to go. It will be a good reliable package that will leak far less oil and when it warms up it will keep the power unlike a air cooled motor. A good equal length header is about all I could think of that might help as it is. Also make sure the fuel is always the same. Also you might try removing the air filter on one of the pulls to see if the intake is restricted next time. The numbers do fall off a little early for better cams though. I would want the revs to go to at least 6500 on a na motor.
The shop that did the work surely doesn't think it should quit at 5700?

Thanks Charlie, yeah I do already have an equal length header on it. I was thinking the same thing on the cams, not what I expected. I bought this motor mainly because it was supposed to have some expensive head porting done to it, and a mild set of cams. The work was done many years ago and the motor was never installed, stored for a long time. I bought it (for quite a bit less than a stock motor) taking a chance that it was as advertised. I could see the porting work in the heads, but couldn't think of an easy way to verify the cams. I did talk to the builder who had records of the engine and so I had some confidence in it. Anyway, I'll probably end up putting some more aggressive cams in it in the near future. I'm guessing they are stock now.

[charliew]

I'm thinking you should be able to find the stock lift specs on the cams and just put a dial ind on the lobes to read the lift. Most all turbo motors go to 6500 and make power to 6k I'm pretty sure. Matt Monson, the guy with the porsche tranny shop in Co. knows a lot about na subys, he is here and on nasioc he may have the knowledge you want. Just search nasioc on the na forum. Probably if the builder was very good there will be stuff about his work and results. On the graph it looks like the motor was just not run to 6500 to see where the torque and hp really fell off. Make sure the air cleaner is not the restriction. I would guess the cleaner needs to flow at least 300cfm to be good. The well ported suby heads usually flow at least 240-260 cfm on the intake on the wrx heads and the 04 sti heads. .400 inch lift would be my estimation on the hotter na cams. I wonder if the springs are stiff enough? Used sti cams are pretty cheap but they are retarded for the acvs but they are used in wrx's a lot for more lift, I think I remember they are a little shy of .400. I have a set and plan on using them in a wrx head setup. I think I remember 5 degrees retarded at static position. I bet just jumping them 1 tooth would put them right for a non acvs motor. I just thought of something, did you check the cam timing on the motor? If a suby is backed up it can jump time real easy. Never park it on a trailer in gear as if it rolls back any it will jump time. The idler only works in the forward direction, it will let the belt get slack if it is backed up and the valve spring tension on the cam lobes helps the cams to jump time at the cog pulley on the crank. You can look at the belt with the covers off and see what I'm talking about. I don't remember but it may make all the cams get advanced cause the crank is the one that changes. There is a guide that is used on some motors that goes over the crank gog gear that hopefully keeps the belt from jumping. It's on the sti motors for sure. I made one out of 2.0 id tubing formed to fit close. The mounting holes are already there on the regular motors oil pumps casting.

I'm sorry I just reread this post and I was talking about dohc heads and your heads are sohc. Not sure about the belt tensioner on sohc.

[Porsche930dude]

Amazing car ! Pretty much what iv been envisioning mine to be like in a year or so! great job (IMG:style_emoticons/default/sunglasses.gif)

[Strudelwagon]

Dean,
I freaking love your car! If I do another one, It's getting modelled after yours. (IMG:style_emoticons/default/first.gif)
Keep the pictures coming!

Steve