I finally had time to throw her on the dyno. The dyno was a DynoJet 224x.

I dyno operator mentioned that he recently had a Corvette dyno day where he mentioned that stock LS3's were throwing down 370-380 rwhp. After watching a few cars before mine it seemed that the dyno numbers were a tad on the low side, but either way it didnt matter because this was my baseline.

1st run- Coolant temp around 165

424rwhp@5900
458rwtq@4000


2nd run- Coolant temp around 210

434rwhp@5900
470rwtq@4000

It was very hard to tell exactly what the rwtq peaked at because the torque curve was so flat. There was also an issue with my car because my wires were too think, and the torque rating spiked in some areas, but I will add that at 2500 she made 450rwtq. Also the airfuel stopped working after the 2nd car which was a bummer, but I think I am somewhat close, but it would have been nice to see it.

The horsepower peaked at 5900, but stayed flat to 6300 rpm's then started a slight decline to 6500. I was kinda suprised that horsepower curve didnt drop more past 6000, but those heads still kept on trucking.

All in all I was pleased. I thought I would have made more rwhp, but I didnt think I would make that much rwtq. I do have to say that I am very impressed with that TPIS miniram intake as it makes power everywhere in the curve, and thats with 3.07's (4+3 still).

Many of you wanted to see what the little heads could do, and it is fair to say that these heads are maxed out. Everyone has there own opinion but I dont think this combo is maximized so there is a little left on the table.

The car was dynoed with the B&B reasonator, B&B mufflers, and 1 3/4 Hooker Headers. I do believe my exhaust is holding me back a tad (15-20rwhp). I will be making some changes and re-attending the dyno for some pulls.

All in all the car ran well, but I did notice that I had a header leak after the dyno runs. The car isnt quiet at WOT, and with the fan blowing on the car, it would have been very hard to hear that noise. I am kinda pissed off at myself for not checking the header bolts (bolt actually fell out, and other bolt was loose). Now I am not saying this affected my dyno number, but I do think its worth noting.

I am glad I got a baseline.I wanted a motor to run on the street that was snappy and had excellent low, mid, and upper hp, and I got it!

Take care guys!




-4 Bolt Bowtie block
-AFR 195cc Eliminator Comp Ports
-11.6 CR.
-Callies Crank
-JE Pistons solid dome
-Crower Rods
-TPIS Miniram
-Comp Cam XE Hyd Roller 236/242 .62x/.58x
-1 3/4 Hookers to 3 inch Billy Boat SS exhaust with reasonators and mufflers

 

Those are some pretty solid numbers. And I always thought that the 195 heads would max out around 550 hp (flywheel), so this pretty much confirms that. Would be nice to see what just a swap to the 235 heads would do. Do you have the 2.05 or 2.08 valve heads?

 

I think he can reach the 450rwhp mark. Just needs to clean up a few things here and there. You may be right on the AFR 195 Competition head limited to around 550-560 horsepower at the crank. This has me thinking about my combination seeing I am using the same heads.

 

With more cam thrown at it, it should make abit more hp and hold on even longer in the rpm range but yes, those heads are maxed out for rpm on that setup. Too small of a port to continue any higher of an rpm peak. Some hp can be made however, but its likely not getting much higher in the rpm range and you will give up some of that torque

with that said, some very good hp numbers! Torque is insane. Thats 34whp more than my 383 but around 100wtq more!! Big cubes make TORQUE! Now get some 220 comp ports and see another 30-40 whp more and alot more rpm

 

It was my pleasure doing the R&D for you, and I'll expect the cheque in the mail.

 

2.08's.

 

Nice job R !

The "peak" RPM will go above 6k rpm, the question is, how much would he gain in the usable rpm range?

More cam is an easy HP adder, but the potential amount of HP added, depends on where his peak CFM head flow occurs too.

I went from a 225 intake duration to a 233 and gained 15-rwhp

I then went from a 233 I.D. to a 238 intake duration and gained another 15-rwhp on my 406 for a max of 428rwhp/458rwtq, all peaked at 6000 rpm using the HSR but I have 210cc heads, I now I could get 440rhwp-470-rwtq with a solid roller cam, but I am done with this 406 format.

 

I pushed 565hp out of sportsman-II heads.

-- Joe

 

I dunno. I think a little more cam and the right intake and that combo is a 600 crank hp winner.

I'm kinda surprised he went with the miniram on that combo. The miniram is worlds better than TPI, but for a 500+ hp motor It's just not right IMO. I had one on the Corvette as well, and the singleplane spanked it in all the acceleration tests.

I wonder what the drivetrain loss is with the 4+3...

-- Joe

-- Joe

 

what intake do you suggest? i am not educated much on the singleplane intakes.....

lets hear it.......

 

I highly doubt I'll be changing cams. Larry, I am sure I would pick up 10rwhp plus with the 210's vs the 195's and I assume loose a little torque?

 

Well, I think that if you went with a 9901 or proram, or even a victor, port matched to your heads, with a 3-3 1/2" runner, and a 4bbl throttle body OR a properly designed adapter and LSx throttle body AND the right cam for the intake (peak around 6200-6500), I think you could probably pick up about 30 more hp.

My hope is that the higher port velocity of the 195s would make reasonable power under the curve to be a nice hot street car, while it would make soo much top end power it would also dominate at the track.

You are running a similar cam to me but mine is an XR on 110*, which has slightly faster ramps. Either way, it's a good cam for a 383 and darn tame on a 406. I imagine on a 421 it idles like a stock L31!

You have more displacement (421 to my 412) and higher compression, and the comp versions of the same head. You have the potential to make 600hp I think with a different cam and intake, if that was your goal.

Then again, high HP naturally aspirated cars are a pita to tune, and are not well mannered which is why I'm running a smaller cam (XR288HR10) on a bigger motor. Superchargers are nice, but when I had a blower on the C4 it was a pita due to the air filter location, heat under the clamshell, etc.


-- Joe

 

I dont think you will see any torque loss and actually may gain some. The curve should stay the same, just shifted to the right alittle (to higher rpms but not too much higher)

195's are REALLY small for a 421" motor trying to get near 6000 rpm. I'm surprised it held onto power as well as it did. A 210 head is a better choice but I wouldnt rule out a 220...the CSA on something like that would be in the 2.4-2.5 range and be great for lower 6000 to mid 6000 rpm ranges. You'd need abit more cam to get there but once there, it would make a ton of power. Well over 600 hp if setup right. Dr J's 406 street bruiser engine made 640hp with his 220cc airwolf heads and a hyd roller cam...somewhere around high 240's deg duration. Rev'd out to 7K rpm, peaked mid high 6000's. HOT street motor.

 

"the CSA on something like that would be in the 2.4-2.5 range"

Maybe you meant the MCSA should be in the 2.4-2.5 range?

 

Correct, minimal cross section area of the head in a 220cc range should be around 2.4-2.5 and would likely go well with a mid 6000 rpm 421 inch motor.

I ran pipemax on my motor for 6500 rpm peak and with it only being a 401, it recommended about a 2.5" MCSA. I'm sizing slightly larger with the turbo application at 2.72"sq. A 421 requires ALOT more airflow at the same rpm than a 401, so the 2.4-2.5" would still work good enough for n/a motors and give good port velocity since it will be on the smaller side of MSCA. I'd have to run pipemax again to verify but its hard to overhead a 420+ inch sbc.

 

It's obvious that the 220's will gain me more power. I still have a 3.07 in the car, and I expect that car to pull harder with the 3.45's.

I will change some exhaust stuff and truly see what the 195's max out at. I believe there is a little left in her......

The car pulls hard regardless. I just took it out for a rip.

At this point in time I would rather spend money on a 100-150 shot then a set of 220's.


Take care guys!

 

"I will change some exhaust stuff and see truly what the 195's max out at"

Yeah baby! Also the upgraded exhuast system will work better for any further mods.

 

Oh no doubt, a very strong setup indeed and has to be a fun car to drive with such fast response that a small port head will give. 150 hit on that setup would indeed be the next best choice.

 

Agreed.

-- Joe

 

yeah a 150 shot would give me in the area of 720 rwtq, and make the car trap in the 135-138 range (guessing) which might be a handful as the car is somewhat light.

 

As long as the suspension is sound and car is solid, it should be stable. My car is tame at 140+ even tho its not a featherweight, but its no pig either

 

Update:

I am changing out the reasonator for an x-pipe. I didnt know this but my reasonator necks down to either 2.5" or 2.75" which is restricting flow alot imo. The x-pipe is full 3 inch.

I think I'll pick up 5-15rwhp, but I cant see many gains in the rwtq. However driving the car it really doesnt need much more then 470rwtq n/a.

I have bought the x-pipe, and will have some dyno info shortly.

 

Was the Miniram ported or bolted on as is?

 

It is ported but I wouldnt say a full big money port job....

No weld or epoxy or anything to that nature.

BTW. It took a while for that question to be asked. Suprised it took so long. Another R&D question answered!

 

This is what my reasonator looks like. I would say its quite a restriction. It goes from 3 inch to around 2.5 inch or maybe even less....




And this is what I am replacing it with.....







I have a feeling the 434rwhp/470rwtq will be higher.....

 

It will be an interesting dyno comparison. I was going to hold off an opinion but what the heck. Being that your dyno results showed the power holding on for quite awhile after peak tells me the exhaust is not the bigger problem. I will say you will pick up some horsepower. I still think the biggest problem is upstream of the airflow from where you are at now. I would not be surprised if you hear a sonic boom.

 

You should get the dyno pulls on vid! Would like to here this moster run.

 

Deleted

 

That is the plan.....

 

... your's our his?

 

Deleted

 

"Im kinda wondering bout mine since its close to his but some decent changes."

Has the potential to make some awesome horsepower. However in my opinion the 52mm throttle body and the MAF will be the drawback. I also think in your case 1 7/8" headers are in order. I would highly consider a mono-blade in your case. It will give better air distribution in the Mini-Ram plenum by slowing down the air going through the throttle body and past the front cylinders.

 

Deleted

 

I did not know you had a 4" MAF. That should work. As to the headers you are right on the border line with the 1 3/4". So if you have the 1 7/8" headers coming that should work good. I don't see any reason why you should not be North of 600hp with that combination.

Make sure the Miniram closely if not matches the intake ports of the AFR 235 heads and carry that up into the plenum. Maybe a slight taper would be in order if there is room. If you have pictures of the mono-blade I would like to see them. Sounds like an awesome build.

 

Deleted

 

Thought you might have been talking about after he installed that x-pipe....

By the way, I'm loving that modified throttle body....

 

You are going with a head that has 40 more cc's, not too mention the camshaft and possibly a sheet metal intake...

In my opinion our combo's are not similar, and certainly not apples to apples. If you dont blow my combo out of the water then something is wrong.

 

Thanks for the pictures. Very nice work. Looks like you used epoxy on the stock throttle body as I was wondering about that.

 

They are close as they sit, other than cam and heads. I will dyno this combo then make the other changes down the road.
And with just the heads and cam difference I'm just wondering what just those 2 things do for power.
Sorry for invading your thread. Ill delet my posts.

 

No big deal bud. I went to the exhaust shop today to get that x-pipe thrown in, and they were too busy, so I will have to wait.

I am going to try my best to maximize the combo, and if i ever need more power I will just put some 220's on her.....

 

How do you run that much compression on pump gas? Was it tough to tune?

 

Timing is set at 28. Octane is from the pump (94). The computer that tunes it is a FAST Classic system, and it wasnt hard. Infact my latest dyno results are with ZERO tuning on the dyno.


Build a big stroker. You will love it........

 

I am going to running a very similar combo next winter.

Good luck and keep us posted!

 

Don't get your self raped-up in the dyno #'s. you can change Hp & Tq large amounts just by the corrections you put in. So in other words you can have the dyno set up so it gives you #'s for a perfect environment. you know that you can always run at sea level, 50*F, 10% humidity, and so on.

 

oh yeah? what combo is that?

 

Well, if i can find a good header(that is big enough and doesnt drag on the ground) I am going with a 421sbc with 215AFR and 292xfi comp cam and 1 7/8 long tube header and with 3" collectors to a single 4" over the axle.

Eventually I will go to a carb, but I dont even know where to start with that.

 

going with 220's now. unleash the ponies!!

 

id love 30-40 more rwhp......

 

Did you get your transmission swap done yet?

 

Cool! Keep us up to date on this.
My plans had to be pushed back a year b/c I had to do headers this past fall and a cage after the summer is over