Fellow Horsepower Junkies,

I am building / actually re-building a never fired up 414 SBC and am looking for dyno information on the FIRST system (or others) stock or modified. This is a torq motor which based on Dynomation software and an independent engineer may make 500 HP at or below 5200 rpm with tri Y pipes and long runner intake. Optimally looking for 21 inches length from valve entry to the plenum, FIRST is 19 which looks okay in the computer model, just shifts the HP a little to the right.

I have a MiniRam but won't be using it, runners way too short.

A little more about the engine, Allpro raised port heads 1.25 w and 2.25 tall ports, flow about 284 at .5 lift. Fuel injection is a FM400 Airflow Performance, sort of a monster, single butterfly 1400cfm low pressure mechanical.

Sure would appreciate some clues on where to find those dyno tests I keep hearing about. Also flow bench stuff???

Jerry Davis

PS, the Dynomation software is easy to use and great fun, may also open your eyes on some things. They just ran a bake off in Hot Rod : software dyno results versus actual engine dyno runs and the results were impressive...

 

This is the highest horse power dyno information I have on the FIRST unit,, which happens to be the same article that is on FIRST Injections web site. I used paint to bring the axis to each RPM, so this is a little more accurate than a similar chart I posted a few years ago.

RPM ---- ASM --- FIRST --- MR
2500 ---- 183 ----- 175 ----- 175
2750 ---- 215 ----- 200 ----- 200
3000 ---- 242 ----- 235 ----- 220
3250 ---- 268 ----- 265 ----- 240
3500 ---- 300 ----- 295 ----- 268
3750 ---- 318 ----- 328 ----- 283
4000 ---- 332 ----- 350 ----- 300
4250 ---- 350 ----- 367 ----- 325
4500 ---- 358 ----- 375 ----- 348
4750 ---- 360 ----- 382 ----- 363
5000 ---- 358 ----- 387 ----- 377
5250 ---- 350 ----- 374 ----- 387
5500 ---- 328 ----- 362 ----- 397

Phaff used the FIRST unit on big cubic inch builds (482cid engines), but I never saw dyno results from the Air Sensors / Electromotive / FIRST intake systems. Most of the dyno info I have on the FIRST are on rather mild 350 builds. I’m running a box stock unit on the 355 in my IROC that’s making more power than the above example. To match track data on the Quarter Jr simulation, I end up with 340 RWHP at 5250, which with the automatic TH350 and non-locked stall should be around 425 horses in the cell. I had a StealthRam on it prior to the swap and liked the intake, but I’m loving this midrange rush.

I’ve never used the Dynomation software, but I’ve used the standard EA software since the early 90’s and been using the EA Pro software for a couple of years now. The regular EA was good, but this EA Pro is nuts on concerning peak numbers,,, and the rest of the curve is very close when known data is used.

I also needed to weld on the FIRST unit for it to work with a set of custom CNC ported “semi-raised” standard port 23* heads (for the 406 in my 1985 MCSS). Based on EA Pro, I’m hoping for around 580 horses at 5800 or so,,, and about the same amount of torque around 4600. For my application, I’m going to have to weld up the back side of the runners so I can reduce the effective runner length by 3”. Hopefully I can get back working on it in a couple of weeks. Some how the same thread is appearing on the TPI and the Alternate EFI board and they do not update each other. Here’s a link to the last page from the other board with pics of the welded intake in case you missed that thread. I’ll post info on the intake / engine combo when I have something to post.

https://www.thirdgen.org/techbb2/sho...5&pagenumber=2

Good luck on your build. You should have no trouble making 500 horses at 5200 rpm,, or close to it assuming approximately 11:1 compression and "the right cam",,,, especially if you open the runners up to 1.875 - 1.9".

 

Dear Mr. BadSS, Thanks a lot for your comments and information, much appreciated. It looks like my ideal length from valve seat to plrenum is 19.5 inches. And the FIRST is about 23.5. So I think we will be doing the same mod. Having said this the FIRST length of 23.5 does still make 500 HP and 560 pounds of torque, more or less with the stock length. Not to mention over 300 HP at tthree grand...not bad. But the G Spot seems to be at 19 to 20 inches.

Please keep me up to date on your project.

Also Ken at FIRST has been GREAT putting up with my endless questions and measuring stuff>>> Jerry

 

couldnt u siamese the base a inch or two inward to shorten the overall runner length to about 19-21inches? seems to work with regular TPI

 

That is an excellent idea, and easier than what I had in mind. Which was building a new set of runners with a tighter radius and meeting the plenum from the bottom / side at a 45 degree angle. I was going to bend up some thin wall to do this but I like your idea better. Will ask my consulting experts but it sounds good. That extra four inches costs nearly 30HP at 5000 / 5500, which is as fast as I want to rev this thing LOL...J

 

If you are interested I can run your motor..If you are I will fax or mail you the 9000 things we need to get started, well okay just 40 or so..J