Built Twin Turbo Setup

can you post the link?

 

It's an easy enough task (though like anything else expensive) but you would lose some of the epic sound. Might help if u ran a single turbo or an x pipe before twins.

If I was going to spend that kind of money I would do a naturally aspirated build. Less power in the end but I think being naturally aspirated suits the F355 perfectly.

 

There's a tt 355 challenge around that was recently for sale, so it's been done.

 

Right, Pete. It's in California now.

Felix Medina did the conversion...
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Felix did this one too...
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Are you considering building something like this? It can be done reliably within reason. Easiest way is to start with a power goal and intended usage and go from there.

 

Making hp is one thing. Making reliable / consistent hp is another thing.

A rear engine boosted car will need to address heat soak issues. You need to make sure the compressed air stays as cool as possible before entering the motor. Intercooler type, dimensions, flow quality, and positioning will come into play. You can run a water-cooled intercooler setup where there is a separate radiator designed to to cool the intercooler/s alone. On a Lotus Exige or Toyota MR2, this radiator sits in the front of the car. However, the 355 has no openings to cool or vent this radiator. You will need to cut out an opening in the front bumper. If you want to properly vent the radiator, one option is to cut an opening in the hood OR duct the heat from the radiator toward the bottom of your car. More cooling plumbing = more weight and most likely more balance issues.

Another option is water/menthanol injection setups. Pre-turbo setups or after intercooler setups. Must log Air Intake Temperatures for desired boost/power levels to see if adequate. I personally don't think it will be 450-500 rwhp.

Low boost (less than 10lbs), wont get you 450 rwhp. I'd say around 50-75 rwhp given no changes in ignition timing.

15 lbs willl get you closer, but you do run some risk with the stock 11.1:1 pistons. Look into what boost levels Exige and S2000 guys are running for turbo setups as their motors run similar compression. Get lower compression pistons if you want more boost.

Exige guys can get away with boosted setups because there is cooling plumbing in the front of the car. Most guys are also running state of the art TVS superchargers with built in cooling aid to combat heat soak. However, most guys arent running 450-500 rwhp either. They are hovering between 250-350rwhp, which is already a monster on the track.

Take this from a guy who owns a boosted Rx7 and an Exige. Boosting a 355 isnt as simple as putting in two turbos and running two intercoolers.

 

You will also never get your get your money out of it. The guy who was trying to sell the yellow one pictured above had to keep lowering the price and it still took quite a few months to sell. He probably ended up selling it for a ham sandwich. Very few 355 buyers would be interested in a bastardized twin turbo 355 regardless of how well it was done.

 

Ken makes a lot of good points but I disagree on the power. 450rwhp would be very easy. With the proper setup 15lbs should be close to 600rwhp. I wouldn't reduce the compression ratio personally. You would need aftermarket engine management anyway so I would do a fuel composition sensor and E85.

Air to air intercooling would work much better for something road raced and the setup on the challenge car above is a good layout assuming there is sealed ducting to the cores.

Also agreed with Brownie. Could be done perfectly but you would likely be stuck with it unless it was a give away price. (which is fine if you don't plan to sell but I wouldn't do it to this car).

 

Cheap, Fast, Reliable....pick any two.

Cheap & Fast, not reliable
Cheap & Reliable not Fast
Fast & Reliable not cheap

Something I always remembered. Anyway, back to the OP question. Like you I would love a ton more power in my car as the chassis could definately take it. The problem is to do it right will probably cost more than I am willing to put into it and the cost of doing it wrong is definately more than I am willing to risk. Unlike a lot of other makes there are no bolt on packages for these cars. Adding turbos it easy. It's the engine management to keep things safe and reliable that gets tricky. If you screw it up a new engine is going to cost you more than blowing up an import.

Check out the yellow boosted 348 Challenge on Youtube. Nice car and you can bet they spent a ton to get it up an running. I would consider buying it, if it was for sale, but I would need to know it was reliable.

Since you don't even have one of these cars yet, are you sure this is the car for you? Sounds like you would be happier with a Vette.

 

That car is stunning! Love everything about it, especially the color.

 

You get to the 450 hp range you start to get drivetrain issues.
Some better drivesharts and coated parts can fix that

Knee bone connected to the ankle bone theory

 

The 355 is an amazing car...buy one drive it love it dont F with it...My2 cents

 

That's correct, James. Both twin turbos retain stock 11.1:1 compression. About 15 pounds boost for the red car yielding 600 whp. The yellow car's boost is set a bit lower for 550 whp.

The yellow car's ducting to the cores is sealed. The intakes are on the rear bumpers. The owner of the red car wanted the modifications to be completely reversible. The two scoops are clamped to the rear lid and so there is no true sealed ducting.
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I agree. That's what Felix did with this one. New pistons and cams, custom ECUs, exhaust and suspension...
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I just let Felix do a good engine adjustment on my stock F355 Challenge...
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Thanks for the pics and info! Your car is putting down some nice power. Have to love peak hp at 8300

What did the white car dyno?

 

Thanks, James. That was April 2013. Felix spent five hours with my car until he was happy with it. He also raised the redline to 9,000.

I'll see him on Saturday and I'll ask for specifics on the white car.

Barry

 

330 to the wheels is strong for an otherwise stock car, that's 360 territory. How much does that run? I may have to invest in that after my major.

 

Pete, that was right after they did the front shock mounts. I was charged six hours labor at $95/hr for the tuning.

 

Very reasonable considering a set of off the shelf chips run over a grand and are not tailored to the individual car. Does your car have the euro (non cat) cam timing?

 

Can we get those numbers on 91 or 93 pump gas? E85 is also tricky because you have to run larger injectors and keep them around 85-90 duty cycle. With larger injectors, some have reported driveability/smoothness issues. e85 is also a dry non-lubricating fuel. It's best to add an additive on every fill up. I ran my rx7 on e85 for a whole year and switched back to pump gas for convenience.

Tim makes a great point about the drive train issue. Twin disc kevlar might work, but i highly doubt OEM will hold.