Grabaldi Racing's badass turbo-4 American Iron racer

The car uses a turbo charged 2.3 liter (140 ci) Ford SOHC engine that was used in Mustang SVOs, Merkur XR4Ti, and Thunderbird Turbo Coupes manufactured during the mid to late '80s. Jack Roush used a derivative of the engine to win three Trans Am and three IMSA titles and the Huber family has used it to win Hot Rod Magazine's infamous "Drag Week" competition.




This particular example will be used in both sprint and endurance road racing competitions. Set up to run in the NASA's American Iron Class, it has to meet strict horsepower/torque to weight caps. Given that the car itself was built to allow the team to run at a low weight, the struggle has been to decrease the power of the engine, a rather curious twist to the normal desire to get as much power and torque out of an engine. Out of the box, the engine made far more horsepower and torque than allowed in class, so efforts have been focused on lowering power while maintaining a broad power curve.




In its current configuration it has an almost stock bottom end. Crower rods paired with a 10/10 stock crank and 30 over stock replacement forged pistons, with a 9:1 CR. The topside is where all the power is made. Bo Christman at Bo-port Racing Heads (http://www.bo-port.com/) was tasked with porting, installing big valves, flow testing and installing his 2.1 cam into a stock iron head. This "Stage 3" head can easily provide the airflow necessary to meet the power requirements. In addition Bo ported and matched the intake to complement the head. A huge intercooler cools the intake charge before it enters a stock 58mm SVO throttle body.




The exhaust side is relatively pedestrian. The team started with a T3/T4 hybrid that was abandoned when it experienced compressor surge at the low power levels that the series requires. In its place is a stock SVO T3 turbo feed by a "40Bob" log style weld-el exhaust manifold . The turbo perfectly matches the needs of the engine for its 3,000 to 6,000 rpm operating range. Looks like Ford knew what they were doing! However, if additional power is needed in the future the turbo will need to be replaced, its operating at its maximum efficiency.

Category:

Autos & Vehicles

Tags:

• horsewidower
• turbo-4
• EFI
• tuning
• chassis
• dyno
• e85
• Haltech

[beluga420]

Looks like an awesome car... but tell me, why only 300 whp? just adding a bigger turbo and reving 1000 rpm more would bring you into 400-500 whp .. build seems a little overkill for the 300 max WHP goal lol, at least with this low whp numbers chances are the engine will last forever!

[dieselgeek]

@beluga420 Read the text that goes with the video. The NASA American Iron series sets the maximum wheel horsepower - not the owner. This is an actual race car, not a street car or "fun build" - it's limited to 300whp (rules change for 2011 allow that to go up a little, or lose some of the added ballast). Hope that clears things up for you.

[turbostang1988]

since your running 9:1 compression, how much boost do you run and do you use race fuel or have some sort of alcohol or water injection?

[dieselgeek]

@turbostang1988 - car runs e85 for fuel, and only enough boost to keep the WHP figures at or below 300whp.

[denmah]

nice work, what size turbo? any other info?

[dieselgeek]

@denmah - check the updated "description" - should cover most questions. Ask any others you have, here. This car is one of my alltime favorites...!

[beluga420]

@dieselgeek Ok thanks, I've probably spaced this information when I was reading!

[Anlushac11]

Been following the build on TF, gald to see and hear it running. Very nice numbers too! Congrats!

[SSChevyManiac1]

I've been waiting to see solid video of this car for a long time. It makes my pants wet.

[Divadmx]

Really nice!

[ladycivil]

Now that was excellent use of an excel spreadsheet. Sounds good and looks like Bob has accomplished building his very own flame thrower. :)

[denmah]

@dieselgeek ah sweet, i guess i saw it too soon haha