Websy21

iTrader: (34)

I have searched and read multiple threads pertaining my question, but would still like help on MY application. My winter project is a 408 with a D1, but can get my hands on a F1 for practically the same price but with meth. This will be mostly a street car. Is this overkill, would the D1 be better? Would the twin 4.5's be suffient as long as the boost wasn't too high, say 14-16psi? Or would you definetely need a FMIC or meth? Would be nice if I wanted to really boost it in the future, but I don't have plans of really going past 750rwhp or maybe 800rwhp max! I only want to run pump gas and not have to spray for the meantime anyways. I also don't want to deal with blown head gaskets, atelast not several times. I basically just want the most realiable street car with lots of power on tap. This is why I went big cubes, so I could run less boost and have just as much power, if not more. Also with extra torque down low for the street. I plan on running low boost to start with and break things in while getting used to the new power. I know the F1 doesn't really run well on low boost and the D1 would be better for this. With the D1 I could probably hit 750rwhp to 800rwhp if I wanted not??? I need to decide on the the F1 soon, thanks for the help

rufretic

iTrader: (37)

I would go F1. With a 408 you have to spin the blower harder to get the boost up. I'm not even sure if the D1 is capable of making 16psi on a 408. If your pushing 16psi on a 408, I think you should be making more than 800rwhp though. Either way, a 408 is matched better with a F1. You can run 12psi with it and then change pullys if you want more boost/power. If you go with the D1, you should be able to get your goal rwhp but you will be spinning it to the max and it will be the limiting factor in your set-up if you ever decide you want more.

Websy21

iTrader: (34)

Thanks for the help, but just wasn't really sure on the twin 4.5's and if they'd be sufficient enough. At this time I really don't want to go FMIC, if I get to the point of going extreme enough, than obviously there is no doubt in a FMIC. Unless I go meth, but even than wouldn't see full potential I'd imagine. I had my heart set on D1 but now you got me thinking????

Drewstein

I tried spinning my D1 to 15psi on my 402 and even with an 8 rib I was getting a ridiculous amount of belt slip and boost would fall off after 12psi @ 5500rpms.

I'm now looking for a F1 myself as my motor out grew my D1. If I already had the cubes I would have picked up the F1 right off, but I started with my stock bottom end unfortunately.

FRCBobby

iTrader: (27)

Drewstein, is you D1 polished?? I will be looking to upgrade from my P1 in the near future. So if yours is polished make me a price and maybe we can work something out as the D1 would be great for me as I plan to stay 346.

If you are 408 definitely go with the F1.

Thanks

rufretic

iTrader: (37)

Go fmic right from the start. It's been proven time and time again plus it's easy to do yourself and will save you money, unless you already bought the kit. You might as well part the whole system together yourself because your going to need a better fuel system and bypass valve than what comes with the kit also. If you need an idea on what you need to get to put a whole kit together yourself, then do a search for my post "homemade D1 fmic". It has a bunch of pics too. Your set-up is pretty much going to need to be custom so I wouldn't try getting away with just buying the kit, you'll end up upgrading everything except the F1 head unit anyways.

TS6

iTrader: (41)

I made 757 with my D1/408 combo. If this is primarily a street car I'd go D1, either way its gonna be too much for the street.

I run a 3.85 pulley and make 14 psi, I'm sure I could hit 16 psi/800 RWHP with a smaller pulley. I just don't see the point, I can't even go 3/4 throttle on the street without blazing the big DR's.

With the smaller ic's and alot of street use you may see higher iats with the F1.

Websy21

iTrader: (34)

Yout last sentence was my main concern as well. For the street I was thinking the D1 would be better and to start off with low boost. It would probably be a funner car do drive on the street with low boost in the mean time as break it in etc. The power gets too be too high with the higher boost for the street, and all you do is spin. If I were to decide to go up higher the D1 should get me there. I know the twin 4.5's are effecient, or efficient enough anyways, up to 14psi as Bob at EPP has stated numerous times. I am sure I wouldn't be seeing the maximum power, but remember this isn't an all out race car. If it was I'd definelty go F1/FMIC and meth.

Websy21

iTrader: (34)

I have actually looked at your exact set up and thought I'd be happy with your results. There is a couple guys on here with around the same numbers as you so it seems to be a nice proven setup, 408/D1. I think that this is more me. I am surprised that you had 14psi on a 3.85 pulley though. The kit I am getting is coming with a 4", what do you think I'd be around for boost? I thought with the extra cubes that it would see less boost right

koji777

iTrader: (3)

F1 and enjoy!

cablebandit

iTrader: (37)

KP didnt seem to think the F1 was a really daily driver friendly blower. I would strongly consider you read his posts about it.

Websy21

iTrader: (34)

Thanks do you know the link by chance? I don't think that if I go D1 I'd regret it but If I went F1 that I might. I just try to look at the picture from both sides

TS6

iTrader: (41)

You can always go D1 and go F1 later if you "need" more power.

Alot of people will say the D1 is too small for a 408, but the reality is that they haven't run the setup.

Then you'll have an assload of people saying to just build a 370 or 346, because it will make the same power. If you're building a several thousand dollar combo and for whatever reason feel like the crank is the place to save $400, then build a 370. But if you're going to buy a good crank anyway, get a stroker crank for the same $$$ and have more cubes. More cubes=more power, anyone who says different is an idiot.

I would also go fmic right off, it is worth the $$$ and will be one less thing to do down the road.

Websy21

iTrader: (34)

I agree on the ci theory and the FMIC too, just not sure if I'd push the D1 to max yet and where I am at with money. If I decide to push the blower to its limits I'll jsut upgrade the FMIC and head unit at the same time. This should be lots for me for awhile and really don't want to hack up the bumper quite yet

Jimmy P

iTrader: (177)

I would go with a F1. I have a D1 on my 402, and it seems to run out to steam uptop. In the process of installing a F1C, after the machine shop finishes up my block with a few upgrades.

Websy21

iTrader: (34)

I feel like I am deciding between a turbo and Supercharger again, LOL Well, ok to you guys with the F1 than, do you drive it on the street much and if so how does it perform? If you had the D1 before what differences where there. It jsut seems like the guys that are going all out race are the ones with an F1, but could be wrong. So basically how would a F1 be on the street? Could I pulley it to run low boost, say to more than 10psi, than turn it up in the future once I am ready and have a FMIC and/or meth?

SELLSZ06

iTrader: (12)

like to hear an answer to that too, guys that have had both how different are they from eachother?
maybe it comes down to is it worth the $400 more for the F1a than a D1?
Iam leanning torwards a F1a myself.

EPP

iTrader: (22)

I sold a local customer an F1A kit for his GTO. He daily drives this car and does not have any problems at all. The blower is a little louder than a D-1SC, but with the hood closed it is not that annoying. Bob

Websy21

iTrader: (34)

Thanks Bob, but I think I am going D1. This way if I do have regrets I can always upgrade later because It will be quite awhile before I decide to max out this D1. Seems like there are a few guys on here with the 408/D1 combo and happy, all depends on goals I guess. Anything over 700-750rwhp is probably too much for the street anyways, LOL

koji777

iTrader: (3)

I run the F1... daily on the street. She is loud.... alot louder than the D1 in my opinion. I'm running the ATI Blow-off valve.... so the car sounds like a B-52 landing... the motor is actually louder than the exhaust. Oh and by the way, there is no such thing as to much power. Thats' like saying my wife is just too sexy