Blake,

With the power you've managed to generate in the IT car, I think a DSP car with your power plant, and wearing the 275/35-15 Hoosiers could possibly do something in DSP. But I still think it's gonna be highly course dependent. It's really going to need to be a momentum intensive course. Any low speed turns feeding straights, and the acceleration of the Bimmers will be really hard to overcome. The Bimmers are surprisingly good in transition, so pushing the momentum preservation capability of the 914 will be the key, hence the 275's I think...

-Josh2

Admitedly I know very little about SP classes. But how do you get 275's under the fenders?

What I do know is them Damn Miatas are freaking fast in CSP with 275's

We will be starting with 225 for now. You can add flares, just not the whole fender is how I read the rule.

'nuff said.

-Josh2

Just got done weighing the car. All stock except for 32/36 weber on a 1.7 with all the stock heat exchangers and muffler. 2.0L Fuch wheels. I was a little surprised at how light it was. 1858# with 2 gal of gas and no top. So we strip the fog lights, radio, speakers and 10# for the flywheel and clutch, it should be close to 1800# when we are done.

I read that you can do a fuel cell.
Steel stock tanks are pretty heavy.

I will be reading over the rules. It depends on how big the cell has to be. My 10 gal cell weighs more then the stock tank.

If I recall, the fuel cell cannot be less than 90% of the stock volume.

Fenders are unrestricted, but quarter panels cannot be replaced as a whole. You can even just sawzall the fenders and leave them open. No tire coverage rule is in place.

My biggest concern of a full-on SP 914 with monster tahrs, is the chassis flex that would result from that much grip. I just see the trailing arm mounting ears tearing out of the chassis...

1850#?!?!?! Wow, that's a lot lighter than I would have expected. Way cool! I can't wait to get my own car on the scales.

-Josh2

Josh2,

Hi. I'm Ivan, Blake's friend with the 70 building up for DSP.

Reading the below link:

wheels, tires, and flares

I believe you currently running 15x8 Diamond with 4-7/8" backspacing. Just trying to clarify the correct backspacing for 8".

Thanks.

Ivan,

Yes, that's what I was running when I was running the diamonds. I had a little rubbing on the front at full lock, and nothing noticeable in the rear after the "fenderizing". This was running the 225/45-15 Hoosier on the 15x8 diamonds.

I think that a well prepped 914 on 225's can be competitive locally, but nationally will require the 275's.

-Josh2

Josh2,

What were your tire temps running the 225 Hoosiers on the 8"s?

Do you really think the 914 can generate enough heat in a 275 for it to work well?

Ivan

SO GT style flare are OK in DSP?

The future owner of the Red Neck Racer will be pleased if that's true.

Yes. If a BMW 2002 can do it (and win at Nationals), I have little doubt that a 914 can.

But remember, this is if you're building for a Nationally competitive car. The 275's will heat cycle out before they get close to cord. So you might want to bear that in mind with respect to tire budgets.

-Josh2

Any flare is ok. As a matter of fact, you could just sawzall the fenders and leave them unflared with big ol' tahrs stickin' out. So long as you don't replace the entire quarter panel, any flare.

-Josh2

Cool, so now back to the motor.

I have all the stock 2.0L parts including a set of virgin 2.0L heads.

Just need a cam as the stocker is LONG gone.

Wonder if Raby can get me a stock cam?

Mallory ignition, nice Euro Header. 40 IDF's on 32mm vents, light flywheel. call it done.

Forget carbs and mallory ignition. FI is the only way to go. Ivan will be running SDS direct fire with a plenum of some kind. We might throw some throttle bodies on to test with. I am playing around with a program for that tonight. I can get you a stock cam.

Wish there was more that can be done to a Type IV to run is Street Prepared.
1" of port match won't do much

cam is going to hold it back

bump compression with Euro pistons ????

Blue print everything to spec.

modify # of Fan blades

Ultra mini Alternator run off an A/C pulley

What else ?

No, but you gotta do what ya gotta do...



Yep, single biggest limiting factor I think. But if Blake can get those kind of numbers from an IT motor (not very different from an SP motor), then maybe there's hope?



Nope. Piston design had to be one which was available in the US. 1 mm over bore IS legal though. So you're already talking custom P&C's as most of the larger P&C sets start at 96 mm and go up.



Yep.



Electric fan conversion is legal so long as you don't alter the alternator MOUNT. But reducing the blades on the stock impeller? I dunno, don't know how much actual benefit it would have.



Yes, and I'd like to see how people might have/are/will do that. I'd like to do the same.

-Josh2

Well I aquired a ultra mini Alt to go on the race car. I have been staring at this thing and my spare motor for a week. One of these days iam going to fab up a bracket and mount it to the big square block (passenger side) of the fan housing where the A/C went.

Blake can tell you how much HP is lost from a fully bladed fan. I think it is like 10 or 12.

What about full flow oiling?

Dry sump would be cool but probably not legal.

Going from a full fan to half the blades on my ITB engine was 2hp and 2ft/tq at the wheels. So with even less blades I would guess 4 more. There is a ton of stuff you can do in SP now. Like aftermarket brake calipers.

Full flow might be questionable as it entails machining of the case. Well, we all know it's just tapping into a galley plug port, but the rules will likely stand in the way of it anyway, as it's a modification of the case. But I'll probably do it anyway.



Dry sump? No. Deep sump or otherwise? Yes. Any oil pump, filter, cooler.

-Josh2

Why not build cheater motor? Its done all the time with other cars in stock classes. Rarely caught if kept internal. When you hang around AX long enough its amazing how many people cheat in those stock classes.

Cause its a cheater motor... I get what you are saying but what's the point? Are you trying to win or trying to win at any costs? So, you build a car that is a winner, does it feel good to win knowing that you had to cheat to do it. Wouldn't it be better to be a winner and know that you didn't have to cheat to do it. In most instances no one would ever know but you.

IMHO, you can build a stronger motor than Blake's because of some of the differences in the IT rule set and the SP ruleset. Biggest differences are 40 over pistons, lightweight clutch, flyweel and the intake being completely free. One thing that I have learned in Spec Miata from engine builders is that you can build an engine on the edge of stock tolerances everywhere and it makes huge differences. Especially with cams, you can make them so the are on the edge of stock tolerances in the right areas and can make a huge difference. Basically, if you can prove that ONE stock head came from the factory in that configuration than you should be ok. In Spec Miata, they are truing up the rules and specing even the machining now to take out some of the gray areas that engine builders were exploiting. We are talking about things like the depth of the plunge cuts behind the seats because builders could prove that they had one head from the factory that had a seriously deep plunge cut behind one seat and so they made ALL of the plunge cuts that deep.

Kyle

Right Kyle That's my interpretation of Blueprinting. Measure and true up everything to the limit of the spec.

Line bore the case and deck the cylinder registers .040 bored P&C's No idea what a piston would cost to have made. Get the rings matched in to perfect gap and then heat relieve the tension for less drag.

No idea why we need to run 20W-50 oil if we build the bearing clearances to run thinner oil. Jake? Insight please.

Get a box of rods and weigh all them to select out the 4 closest.
Same with wrist pins.

Don't know how much a set of KB's would run, but I priced out a set of 95's from another vendor (damn, can't remember the name now) at around $500 for a set of custom 95's.



Actually, you can one better... Get a big box of rods, weigh them all and find the single lightest one. Then take three more and lighten to match. Same with pins, and pistons. SP rules allow for -balancing-, but not -lightening-. So the argument, and as far as I'm concerned, a totally legitimate one, is that you're simply balancing the parts to match. There's one part of each in there that isn't modified, so you're good.

This is the motor that I had -intended- to build, but never got around to.

I think that if Blake can get those kind of numbers from an IT motor, that there's power to be had in an SP motor.

-Josh2

I'm with Joe. The only person you'd be cheating is yourself.

It's not like there's big money on the line or anything. It's a $20 plastic trophy.

A cheater motor might not be caught, then again it might. People HAVE been protested for illegal motors, some have been found legal, others have not. Do you want to be that guy who gets the boot for a cheater motor? I don't.

Some things I'll argue in favor of. A full flow setup for instance. While it might not be legal to the letter of the rule, it's arguably not a competitive advantage at an autox.

Same would go for upgraded chain tensioners on 911's. I'd look the other way, others might not. But it's technically NOT legal for an SP motor because it's an internal engine modification.

Now, I'm all in favor of pushing the rules to the bleeding edge, so it's a fine line to walk on. But if I can easily come up with a protest for whatever I'm contemplating, and think it would stick and result in a DQ. I'll pass on the idea.

-Josh2

Oh, and speaking of cheater motors....

The Spec Pinata guys have it DOWN. I recall hearing of one guy who ran an entire season with an ABSURD cheater motor.

The rules require that the bore of piston #1 be measured for compliance. So all #1 bores are measured. Nothin' in the rules about #2, #3, and #4... Guy built a 1.6L (so, no restrictor), and bored the other three cylinders to accept 1.8 pistons...

Ridiculous...

-Josh2

yeah, I have also heard of one guy that had nitrous but I have never actually seen it. It is not the guys at the front you need to worry about, its the guys in the middle of the pack. Honestly, its pretty easy to know who the cheater guys are on the track, he is the guy that PARKS it in the turns and motors by you like you were standing still on the straights.

Kyle

In my last job I built numerous Spec Miata engines as well as doing the machine work that went into them. I know exactly what it takes to make HP from a stock engine.

This is exactly what I did with my ITB engine which is now going in this DSP car. The rods weigh anywhere from 800g to 760g. The wrist pins weigh from 200g to 160g. I even weighed crankshafts. Everything deck height is the same, each head has the same cc. How else to get 108whp. I think this engine will make more power once we add the direct fire and have wasted spark and let it breath better with more intake. I hope to be in the mid to upper teens with it and still use the stock cam.

Sweet stuff Blake.

Kyle

Drive faster. If you are only capable of pushing a car to the limit on 225's then 275 will not make you any faster.

Friend of mine let me co-drive his CSP Miata. High speed stuff had him lifting his right foot. With him in the pass seat I stuck the car in the sweeper with my foot planted. Car stuck and he seen the light. Now he needs a NT trophy last event was one spot out.

In regards to tire temps. about 115 to 120 on the 275's

Hoosier wants the tire temps in the 140-150 range for autocrossing. I keep hearing people are getting over 100 runs on the tires and they still have lots of tread on them, they are just heat cycled out. That tells me they are not getting the tires up to temp. I know on my car that I can hardly get to 150* racing it. Good info though. We will keep thinking about.

Getting tires up to temp is a major problem up this way....the rears aren't too tough but them fronts.... Cool temps, asphalt, and a light car work against you. 2 drivers work for you. Bout 40 runs & the tires start falling off. THe only thing I've come up with is 2 sets of tires......run the junk at local AXs and the good ones for "big deal events". If you come up with a solution be sure to let us know.

I have 6 cantis that have nearly 1/8 inch at the dots, but are heat cycled out.

We should have better weight distribution since we will only have a 4 cyl in the car and all the headlights and stuff need to be there. I think we are going to run 225's for now.

225 Hoosier is a lot of tire for a stock engine to push around.
I would think the limit is 245s, and the parasitic drag of a set of 275s would offset any increased grip.

I respectfully disagree. Grip is disproportionately more important than power when dancing around the cones. Parasitic drag of wider tires has much more of a detrimental effect when the straights are really long (like road racing), but when the straight is barely long enough to go up a couple thousand rpms in one gear, and the course is more linked maneuvers than straights, give me grip.

That being said, the 245's would be great if there were a 245 that was short enough. But the best 245 is the 245/45-16, which is considerably taller than the 205/50-15, 225/45-15, or 275/35-15, which are all the same height. The short 275 Hoosier is THE ticket for the smaller cars right now.

And if you think a stock motor isn't strong enough to push the 275, how much stronger do you think a stock motor in a BMW 2002 is? National Championship car in FSP this year. Yep, running 275's...

-Josh2

I wonder if 225/45 up front and 275 in back.

I guess it would depend if the car pushes or not.

I have a lot more rear temp than front. My car NEVER pushes on new tires no matter what I am pulling off. 1.4 lateral G's and it more of a matter to keep the rear stuck.