3.6L Boxster GT Racer

[Eric523]

Originally Posted by insite

incredible. did you make that top, or buy it? never seen one like that.

we made it. Made a quick thread on it here : http://986forum.com/forums/boxster-racing-forum/44139-new-boxster-hard-top-prototype.html

[Eric523]

in car video from Festival of Speed :

[jaykay]

Sweet video...love the part where you kept momentum and it bouncing off the limiter to try and suprise the rsr out of the chicane section.

Lots to learn from just watching your stuff

[Dr.Strangepork]

Originally Posted by Eric523

Been sharing a bit of my GT class Boxster build over the last few months. After a year and a half in the BSR I decided to make a jump to GT class power/weight racing. Considered selling the BSR and trying to get a cup or build a 911 car, but the Boxster platform has been so much fun to drive.

Fantastic thread. What are the rules in GT class? Does the car just have to fall within a certain power to weight range and you can do whatever else you want to it?

[Dragonwind]

Thanks for keeping this updated Eric! I love what you've done.
Chris

[Eric523]

Originally Posted by Homeboy981

Eric523,

WoW! Now THAT is a serious car! Thanks for even letting me view it here!

Got any driver openings?

Just a thought….but why not go with a dual exhaust straight out the back? It occurs to me, and I'm not a mechanic or a racer car driver. In your exhaust setup at the rear with the bends going back to center, you could shave another 3 lbs. in exhaust tube weight alone. I'm sure you need to 'marry' the pipes to balance it out but could you do that with an "X-tube" type setup closer to the headers or a "bleed" tube of lessor weight and diameter?

Also, would like to see your intake system…IF you happen to have one of those pics.

Were you the only Box represented in the field? Didn't see any other 'side' intakes.

Keep up the good work…and keep us posted! :dance:

Thanks! On the exhaust stuff, yes we do like to merge the two sides together. With the suspension subframe and longer 6 speed transmission case, there isn't much room to do any merging further forward in the car. We can't run any pipes underneath because of the low ground clearance either. The pipes I have now are a little longer than absolutely necessary, but that is because we wanted to be able to insert the largest mufflers possible in that straight section in the back leading up to the merge. Every once in awhile we run tracks that have a maximum decibel reading, and the option of adding mufflers there was a goal.

I think there is a few pictures of the intake set-up earlier in the thread. Basically some 3" aluminum pipe running from the throttle body into the rear trunk by the coolant tank. The right side air scoop on the side of the car has been modified to feed air through the right rear quarter panel and into the trunk. A larger cone filter, some sensors, hoses and hose clamps...nothing particularly fancy.

I was the only Boxster that far up front. There was one other 3.4L conversion Boxster there that weekend but it was a few seconds back. There is a Cayman in my class that has some side intakes too but we ran pretty good gap on that car as well.

[Eric523]

Originally Posted by Dr.Strangepork

Fantastic thread. What are the rules in GT class? Does the car just have to fall within a certain power to weight range and you can do whatever else you want to it?

Thanks. Very few rules in the GT class so we can pretty much do what we want.

We have 3 types of tire to choose from: Slicks, DOT <100TW, and DOT>100TW
Cars with slicks must run the most weight, less for <100TW, then even less for >100TW. I've chosen slicks, as does most everyone in the higher classes because the DOT's overheat on the higher HP/higher grip cars. We also have a great contingency program with Yokohama, which is why I have so many of their stickers on my car. Last race weekend, I won a full set of 4 valued at around $2k for my class wins.

Class with Slicks

GT1 less than 7.01 lbs/hp
GT2 7.01-9 lbs/hp
GT3 9.01-11.5 lbs/hp ** I ran 316rwhp and 2850lbs last race (restricted hp and added ballast)
GT4 11.51-14 lbs/hp
GT5 14.01-16.5 lbs/hp
GT6 above 16.5 lbs/hp

Weight is including driver and fuel and you must meet weight at any time during qualifying or the race. We always get weighed in after the race (top 3 finishers).

Only rules are:

-Car are limited to one wing (no front wings attached to the hood). Wings must be single element (no multi element wings). No active or in car adjustable aerodynamic devices.

-All engine swaps must be of the same manufacture.

-all tube frame cars must take the slick weight requirements

-maximum of 350lbs of ballast

-switchable ECU's must be declared, inspected, and explained

[Eric523]

fresh dyno certification runs for the POC event at Buttonwillow this weekend. The boss programmed a drop of about 10 HP to lighten the car 90lbs.



The girlfriend's pink one is coming out to race this weekend too!

[Crono0001]

Lucky girlfriend

[Eric523]

very lucky girlfriend, very fast too!

[Eric523]

Here is a video from qualifying on Tuesday. Was about 3- 4 seconds a lap ahead of second place on Saturday so I decided to run up a class on Sunday. Unrestricted the motor and went for it at +600lbs or down 60rwhp in the GT2 group.

It was pretty darn hot out there, 100°+ ambient temps and 150° track temps, so it was a little slippery...

Buttonwillow GT2 Quali in HRG GT Boxster - YouTube

[Eric523]

[Eric523]

some photos from last weekends event taken by Max Flieger.

[Eric523]

Haven't posted in this thread in what seems like forever.

Lost a motor on the banking of Auto Club Speedway and started planning a new ultimate Boxster engine... It has taken quite some time to get everything together but things are starting to move again.

Bought a 3.8L X51 crate motor. Had a scarred cylinder 3.8L engine sleeved for an increase to 4.0L. Going to use the 4.0L case, worked X-51 heads, X-51 intake, custom 13.4:1 JE Pistons, Carillo rods, GT3 rod bearings, and our new dry sump system. Sold my Pectel ECU and will be making the switch over to the Motec M1 series. There will be a bit or wiring involved in that swap also.

I've finally got the custom pistons in hand from JE. They spent some time scanning the cylinder heads and we clayed the motor to get the valve pockets filled up as much as possible. Their milling process also took out a lot of weight, so we are down to 386 grams.





The dry sump system still has some work left, but it should be pretty trick. More photos when we are further along with assembly. Might be the first one of it's kind on an M97 engine? We may actually end up over 400rwhp and live for awhile...

Also had time to get the custom roof mold done. Selling off the prototype and making some production models now. Hopefully they will offset some of the cost in getting that thing built. The new version is a lot lighter! It is a mix carbon, fiberglass, and foam stiffener.

[rastta]

Damn - that's going to be pretty damn quick unrestricted. Can only imagine what a worked over 4.0L could do in my Boxster.

[Eric523]

Originally Posted by rastta

Damn - that's going to be pretty damn quick unrestricted. Can only imagine what a worked over 4.0L could do in my Boxster.

I don't think anything without a turbo will be running away from me. That's the plan anyway...

Can't wait to find out!

[j.fro]

Droooool!!

[El Vikingo Tropical]

You are making real killer. ..
I have been reading about your car for some time and it has been an inspiration for me.
So now I'm just to beguine to build my own unit.
I have found a cheap roller chassis from a Cayman to start my little project but with a 3.8L engine.

Tank you!

Regards
Jan

[jimk04]

Eric, I've followed all your posts on here and Renntrack so it's good to see you posting about your Boxster again.

Will be following this closely.

Welcome back!

[The Radium King]

Eric!!! pls tell us about the engine and the dry sump - how's it coming along?