hpfiend Posted August 17, 2012 Report Share Posted August 17, 2012 (edited) Hey all looking for opinions-- goal is to run low 10s in a 2700 lb chassis Probably 650 rwhp to do it consistently without some crazy expensive chassis/suspension work? It has room for 26x10.5 slicks and is just a leaf spring rear suspension with traction bars as it sits. Have a big engine in a little car (sbc in an amc gremlin)- headers had to be dented in pretty well (by the previous owner) to clear the steering rods and the frame rails. They are so close that they occasionally make contact with the shake of the lopey cam. Running the headers forward and up/down for a big single turbo would obviously avoid this situation but there would be a lot of down time on the car to build the headers. Also with the large radiator and transmission cooler really only room for a water to air cooler or a drag only ice intercooler setup without a condenser... I have made headers from scratch before so it would be easier this time but time is previous with two kids and work. Are there any high enough flowing SBC manifolds I may be able to use/flip to save time on hotside fabrication? Slap a centrifugal blower on there and cog if needed to get the boost needed to force through what I have now or use the same high flow manifolds from an old vette or something of the like might offer better flow (or at least compared to the dented primaries I have now) and fit a lot better. I have tons of room in the back for a rear mount turbo setup (gas tank removed for a fuel cell in trunk) but dont know if the headers/manifolds would flow enough to make it work right... pretty much stuck with a gen 1 sbc as the mounts are custom and made for that and I have no desire to start over from scratch with the swap (Been there, done that). Obviously my goals would be easier with an LS anything but lots of guys have made plenty of power with the gen 1 sbc. while it would be sweet, a NA setup (DZ302) is probably out of the question unless I were to completely rework the firewall, floorboards and tunnel and make a proper set of rear facing headers... maybe juice it a bit as well for those power numbers and be *cough* reliable. Thanks for your opinion in advance! Edited August 17, 2012 by hpfiend Quote Link to comment Share on other sites More sharing options...
twistedfocus1647545489 Posted August 17, 2012 Report Share Posted August 17, 2012 Looks like you're possibly headed many directions at once. As primary sizes go I would think a set of 1-3/4" would probably support what you're looking to do easily, assuming you're sticking with forced induction and not a huge displacement. For N/A on a high revving small displacement engine, like the DZ, or a larger displacement engine (377+) I would look into 1-7/8". I hate the idea of using factory manifolds. Some of the best factory manifolds are still utter shit, but much like the "double-hump" heads, some have a reputation for being way better than they are. It should be pretty easy to make a set of 1-3/4" headers even on a car that small. It's likely more important that they are designed and built correctly than the size of the tube, so choose your builder wisely. Incidentally, depending on many factors of course, you can probably run those times on a good bit less HP. More is always better though! Quote Link to comment Share on other sites More sharing options...
Nickey4271647545519 Posted August 17, 2012 Report Share Posted August 17, 2012 I'd think in a gremlin, that a healthy 400sbc based engine would get you into the 10s with relative ease. Even more so if you hit it with some spray. Quote Link to comment Share on other sites More sharing options...
AJ Posted August 17, 2012 Report Share Posted August 17, 2012 Being a drag car you should be in the 1 7/8 header range. With a power added you should look into stepped headers. Quote Link to comment Share on other sites More sharing options...
twistedfocus1647545489 Posted August 17, 2012 Report Share Posted August 17, 2012 From reading his thread, I got the idea it was going to see some street duty as well. I totally agree that erring on the big side doesn't usually hurt on a race-only car. Quote Link to comment Share on other sites More sharing options...
Nate1647545505 Posted August 17, 2012 Report Share Posted August 17, 2012 I worked with an SB2, 408ci motor with some reallly tiny primaries. I think the setup was something like...1 5/8" O.D. primaries -> first set of 2.125 O.D. collectors -> final collector 2.5" ---> expanded to 3". Quote Link to comment Share on other sites More sharing options...
Nate1647545505 Posted August 17, 2012 Report Share Posted August 17, 2012 This is what we were seeing on the computer side, the orange/tanish line is MAP kPA. It's near atmosphereic at the start, and slowly tapers to ~85 kPa (97 kPa was nominal) @ 7500 RPM. http://img262.imageshack.us/img262/2017/kpadropns8.png Edit: This was done with no filter, different pressure tap location. Torque fell off the face of the earth @ 6500 RPM and the car only laid down 550whp - Mustang. The setup was literally a SB2.2 auction motor. The cam was roughly 268/274, .750 lift @ 0.050, 13.6:1 compression, on 109 Octane. Quote Link to comment Share on other sites More sharing options...
twistedfocus1647545489 Posted August 17, 2012 Report Share Posted August 17, 2012 Matt's RX7? Didn't realize he had such a weird exhaust setup, if so. Quote Link to comment Share on other sites More sharing options...
Nate1647545505 Posted August 17, 2012 Report Share Posted August 17, 2012 Neg, this was Alex Dorsey's 69 Camaro. Lots of small issues that really complicated the project (cam/crank trigger, wiring gremlins. etc) Matt doesn't believe in EFI -- he's one of those fuel brick guys. Quote Link to comment Share on other sites More sharing options...
twistedfocus1647545489 Posted August 17, 2012 Report Share Posted August 17, 2012 Matt doesn't believe in EFI -- he's one of those fuel brick guys. Hmm. I guess I naturally assume all road racer types are EFI guys, though there are always exceptions. Also, I have never actually seen the car in person. Just going off my assumptions. Quote Link to comment Share on other sites More sharing options...
Nate1647545505 Posted August 17, 2012 Report Share Posted August 17, 2012 Hmm. I guess I naturally assume all road racer types are EFI guys, though there are always exceptions. I think after years of me annoying the bejesus out of him to make the switch, he may finally consider it. Quote Link to comment Share on other sites More sharing options...
twistedfocus1647545489 Posted August 17, 2012 Report Share Posted August 17, 2012 I think after years of me annoying the bejesus out of him to make the switch, he may finally consider it. http://thedecaturminute.files.wordpress.com/2009/10/borat_great_success2.jpg?w=500&h=375 You may know Rusty, an announcer at MidOhio. He finally made the switch about 5-6 years ago (Toyota Corrolla LOL) and has been kicking himself ever since for waiting so long. Quote Link to comment Share on other sites More sharing options...
Xbomb Posted August 17, 2012 Report Share Posted August 17, 2012 I run 1 5/8th headers and you guys see how my car does. Just imagine with some big tubes!!! lol Quote Link to comment Share on other sites More sharing options...
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