OK this sounds like an odd question but bear with me a sec. Which engine option has more appeal in a 308? Carburetors or a twin turbo? Sure everyone wants more power, but sometimes the simplicity and raw sound of carbs beats that. One of our 308's is undergoing a complete restoration/minor mods and the option to either put in a carb or twin turbo engine is looming. Either option entails a complete new engine build. For the TT build I have access to a late model 208 turbo intake/intercooler. It comes down to trying to get a feel for which would be more popular, why? simple really, once done the 308 will be up for sale. Now to figure out how to do a poll.....
Since you're saying "restoration/minor mods" I'd say make it an exotic carb car. If you were going for something dramatic and intended to grab attention and generate buzz, the twin turbo concept would be unbeatable!
I don't agree with this.... Make your car what you want - Sure there are limitations but Scott has found those and is one of the few people who can make a 308 as fast as a modern car with a lot of thought. With the singer's and everybody out there making essentially "pro-touring" cars, this is a growing demographic. I would love Scott to add a hundred or so horses to my car with a 360 crank and bore. I just can't afford it, yet! I love the growl of carbs, especially since I just tuned mine and they are great! Scott, Perhaps you can pump it up and go with IDF's or IDA's. I have seen your simulations for ITB's - that would be cool too! TT, well, it takes away from the visceral experience a bit. Unless you are going for another one of your GTO themes, I would stay away from it. You build amazing machines man, I hope you do mine at some time! Spencer
That's really about it on the TT option, attention... but would it be good or bad? the $64k question. Turbo's have come a looooooong way from the 80's. The appeal would be the wow factor of a TT 308. Though the late 208 turbo manifold leaves a lot to be desired it does have the factory original look and in my view is better suited towards a TT build as it has a more finished look. As much as a I'd like upgrading the Carb's, that won't happen. The heads require significant work to get useful flow to where doing that would manage an increase in Tq where it would be most useful. The most expensive option is the 3.5 or 4L NA builds, however those are slated for other projects at the moment. This is intended to slip in below that option. For those not familiar this is what the late 208 turbo engine bay looks like. Image Unavailable, Please Login
Turbo. No one ever said "You know what would make the 288 GTO really cool? Get rid of those turbos and run carbs instead!"
The TT would very likely be a dry sump, EFI, coil on plug, fully tune-able monster with the ability to run on ethanol. To me that sounds like loads of fun, yet many prefer carbs and honestly I can't wrap my head around why? If it was a 12cyl then I could see the draw as yes there is something about a 12cyl carb'd engine popping on the downshift. Buuuuuuuut the Piiiiiissssshhh of a BOV has an appeal all it's own!
The carb crowd is certainly a passionate bunch. To me, fuel injection is the Great Step Forward and I can't imagine buying another carb car again (okay, a 1957 Testa Rossa would be nice). Perhaps the FI people are just a little quieter than the carb people. Your clarification of design goals was helpful: that this is a lower price point upgrade compared to your full-on 3.5L naturally aspirated conversion. Although I don't really like turbocharged cars either, I vote for the TT option. It may or may not raise the 308 to modern performance standards, but it will raise the 308 to modern reliability standards, which I imagine is something most people want. Whether it is slow or fast, a 308 has nothing to prove.
I agree that everyone has the right to do what makes them happy but I see this as turning the car into something that it was never intended to be. In that the 308 is so intensely focused a design I don't see it as being well suited for such a reinvention. But if he's intent, I wish him every success.
With the current 308 market, I would go through it and put it back to factory spec, albeit with all the old rubber bits replaced and the suspension rebuilt. So... I'm probably the wrong guy to ask. I wouldn't be in the market for a TT 308 unless it was at a very steep discount and reversible. It's already so hard to find a really correct 308.
I used to really get bit by the speed bug, then I got into motorcycles. Now I just like my car to start every time I put the key in. Im there with bullfighter. If I had the cash, and needed to make mine faster, I'd do the 3.5 build before anything else. I might do an ITB setup someday, just to wake the motor up. I love my fuel injection, spent too much time dialing in carbs as a young kid to ever actually want a carburetor on something I use.
I guess that this is a good question, but with three types of 308's, why ask? Most of us have voted with our checkbooks already.
I appreciate the input here. I'm not overly surprised that carb's hold a special place. No offense to the purist, NFF does not do factory spec original builds. We focus on bringing the 308's style into the present by improving and updating where needed and possible. The reference to Singer and what they are doing with Porsche would be very similar. What started out as engine builds has grown to now encompass the entire vehicle. The reason being is that the substantial increase in Tq/Hp effects the handling requiring a change to the suspension and brakes. The cooling system also needs to be over-hauled. Updating the engine management to a modern ECU requires going thru the wiring harness, etc.. so it become apparent that the entire chassis needs attention and a complete overhaul makes more sense. So with that these builds end up a special edition NFF 308's.
With what little I now know about the 308 and maintenance, I would: Go with ITB, integrated with electronic ignition - BINGO almost all of the fussy, difficult maintenance issues disappear; no more points, expensive distributor caps, carbs going out of adjustment, better throttle response, better mileage, better HP and Torque, better driveability, in short, almost a modern car, in terms of maintenance needs and reliability. THIS IS NOT A SMALL THING. It will have the sound of carbs, but better in every other way. I would go with the Forza, (SMG), T belt solution to ease that worry, (personally haven't done this but would like to). I'd do the full on Scuderia Rampante hose upgrade. Aluminum radiator, spall fans 16 inch rims, extreme performance summer tires, good shocks, new rubber or poly bushings, bigger f/r bars & slightly stronger springs, my 400/350 is just a bit heavy for street only, (great on the track). More brakes and a good stereo Birdman's fuse block and new bosch relays. Good euro lights with better wire and relays. Maybe tune up the windows, throw a tubi or capristo on it and an AOOOOOOGHAH horn Sorry, sometimes, I just let my mouth run off unattended, chris
Chris you forgot the (2), NFF = Nicks Forza Ferrari I've worked with the ITB's available from redline weber, they leave a lot to be desired. For ITB's to be smooth and drive-able requires a progression circuit and ICV control, not something available on any of the 'kits' or plug and play ITB's for custom builds. That leaves adapting modern ITB's from a production mfg or doing custom mfg on my own. Neither is very cost effective.
Well since you have already said returning to stock isn't an option I'd say go with the TT option. So what does that really look like on a 308 though? Where in the heck do you fit the turbos without doing a full-on 288 style stretch and turn job? And by the way as a sort of coincidence my current garage is one carb car (308) and one TT car (Cayenne).
I'm intrigued. I've never seen a GT4 with a twin-turbo, or even a single turbo for that matter. …and mine's apart too! And N.B. is a LOT closer than Folsom… …just saying'
I have a turbo car (85 Euro 308 QV). Good luck with getting twin turbo's to fit. When Norwood's built my system they said they would never do another twin turbo (308) because of the lack of space. I assure you that is true. There really is no room for the second turbo or inter-cooler. One large turbo and water to air inter-cooler works really well for me. You will need custom turbo style pistons and copper head gaskets. You should add steel o-rings to the top of the cylinder liners and replace the (rubber/phenolic?) gaskets under the plenum with custom made steel pieces with steel o-rings. Of course you will need a complete electronic fuel injection system and programming. I use Motec. My engine makes just over 500 RWHP on AVGAS. I use 100% AVGAS all the time. It has been very reliable since I built it 10 years ago. You can make a 308 into a super-car. It just costs money .
My choice would be a stroked engine with ITBs. Then you get more power, modern FI and ignition, and the sound of carbs. Never mind, saw that you don't want that. TT it is, but use small turbos so they spool up fast.
I REALLY love the turbos, owned two 208 turbo GTB/GTS and still a BiTurbo Mercedes G63, but ... a 308 MUST HAVE the Carburettors and NOTHING else.
