I finally got around to getting my 406 dyno'ed the other day....pretty impressive considering its still TPI. Heres the lowdown of the motor

400 bored .030
Dart 220cc Iron Eagles(2.05/1.60valves)
GMPP forged 1030 crank
SRP pistons
GMPP connecting rods
COMP XR276HR-10 cam
1.6RR's
TPIS bigmouth intake
TPIS big tube runners
TPIS CNC ported plenum
58MM BBK tb
ACCEL 30lb hr injectors

The first run was on a improperly burned chip....it was an image of a friends TPI 383.

First run

325HP@5300rpm 410ft lbs@3000rpm

Second run was made with a "somewhat" better chip with much more emphasis on the lower VE tables, injector flow rate...etc etc

387@5500rpm 450ft lbs @3000rpm

There is much more left in tuning I think....I think with the right fuel pressure, timing, etc....I could hit 400HP at the wheels....Just thought Id share with you guys. I think 450 "might" be possible with a mini ram or HSR.......lemme know what you think...

 

Those are some damn good #'s, that tpi system must flow well probably about like a Super Ram in order to put that much hp to the wheels. Either way those are great #'s.

 

Thanks....I honestly didnt expect numbers like that. The runners and plenum have been "siamesed" and port matched....and the base has been extensively ported/siamesed as well. My exhaust is Hooker LT's with the Mufflex Y and Dynomax Ultra Flo muffler.......When I get the money for the HSR or MiniRam, I cant wait to see what the numbers read...

 

Awesome numbers. I'm surprised that the HP peak came at such a high RPM. I would have guessed 4800-4900 RPMs for HP and 3200-3400 RPMs for torque peak. I guess that's mostly because of your cam.
Any track times?

 

No track times yet....I still have to get my 10bolt swapped for something a little more sturdy I think the rpms peaked that high because of the duration of the cam. I would have thought a 406 with the "wheezy" TPI would peak short of 5Krpm, but I guess its breathing better than I thought.....should have some track times sometime soon hopefully.......

 

When you get a chance can you post the dyno plot? I'd really like to check it out. Also - which dyno was it (dynojet, mustang, etc)?

Tim

 

I dont have the curve chart yet, only the chart from the dyno itself. I will have the curve later this week via email. The dyno was a SuperFlow and they were using WinDyn?? software. Please be advised that this chart represents engine dyno numbers, NOT chassis numbers. The numbers I was quoted from the testing engineer were figured at a 15% loss for "rear wheel" hp numbers. Only my engine was dyno'ed as my trans/rear are not rebuilt as of yet. The chart the engineer sent me actually shows peak numbers that are 500rpm respectively different from what I was quoted over the phone. Not sure whats going on there....but hopefully the curve will show something different. They did engine dyno with the same headers Im using, with the exception of dual 2.5 exhaust that was roughly the same length as it would be on the car. I hope to have the curve chart soon.....and I will post as soon I as get it.

 

Ok,

Engine dyno. This is making a more sense now. 15% is for a manual. Figure on 20% at least for the auto. Are your TPIS LTRs fully siamesed? Any pics?

Tim

 

Yeah the TPIS runners are fully siamesed...as is the plenum, and base. I didnt do the work myself, I actually bought the setup from TPIS about 6mths ago. It was a setup a former customer had made and ended up going with a mini-ram. I dont have any pics yet.....I have some photos from a camera, but no digital camera as of yet....and no scanner right now If I could get this car to run right, maybe I could afford to buy one Ive always heard 20% for an auto also, but he said he was figuring that based on a "modded" auto trans. Im hoping to get to the track before it closes to see what the real performance numbers are.....

FWIW, I would have went with a HSR or mini-ram, but I got such a good deal on the TPI intake, I couldnt pass it up. Wonder how it would work on my 305???

 

those are some really good numbers...
450 hp and 530 ft lb...from a tpi!!

not for nothing , id get it tuned right and keep the tpi on it...

as it sits now you want to shift before 6 grand...and adding a HSR or MR would only want more RPM's....loosing low and mid range power for 30 on top....IMO id leave it as it is

 

awesome numbers!! Sounds like an awesome truck motor!! man 530ftlbs!! Thats one hell'uva 406!

Watch out on the HSR and Dart heads... i heard someone had to use shimms to put between the HSR and heads to make them fit pefect. I REALLY need to find a 400 block.

 

good #'s!!! i wish i coudl haev went to a 220 head.. but im lucky to be passing emissions with my 195's.

 

Thanks guys....Im finally getting the PROM "right". It idles ALOT better now. Im going to get it chassis dyno'ed after I feel the tuning is close. Im hoping for somewhere in the 11's at the track. I have an article Im looking at here with an 87 T/A with a 455 Buick that made 350hp and 425ft lbs AT THE WHEELS. Its basically a stock block with a little better cam and heads. He is deep into the 11's and Im sure that big buford block weighs more than my small block...lol

 

Give it more fuel - shoot for an AF ratio between 12.4 - 12.8.

What your total spark advance BTW?

 

Awesome numbers! This is a combo that I am considering for my Z28. I have a few q's for you.
1. What compression ratio?
2. A hydraulic roller cam? How did you change the block for the hold down, or did you go with aftermarket lifters?
3. How difficult has it been to tune for idle quality?
4. How much stall will this combo need?

Thanks in advance,

Dave

 

Glenn, my total spark advance is 32deg. Thats what the engine builder recommended to start with. I might try different settings and see what that gives. I was also wondering about my air-fuel, but was wondering what was too rich??? Will I know instantly if the engine likes more fuel??


BIRD, my c/r is 10.3:1. I got away with higher compression on the iron heads by cleaning up the chamber a little and slightly porting the exhaust port some. As for the cam, its a retrofit and it came with COMP lifters. I got the cam as a package, with springs, lifters, pushrods, etc. As for tuning for idle quality, it was rough at first. The stock PROM wouldnt even let the car run hardly. Ive finally got it to idle around 850 for now, and it seems relatively smooth....but really lopey I have a 2800 stall TCI converter in my rebuilt 700R4 with a corvette servo and sprags, etc etc etc. I felt I didnt need a higher stall because of the TPI's flat torque curve.

 

KYL98- Thanks for the info! One more easy Q, What are the specs on the cam you picked, there are so many different xtreme cams that are similar I can't tell which one you might have.
I am looking at staying around 225 or below @.050 and 112 or 114 CL so it will idle good. I don't care about 5500 and above, if I did I would go HSR. I never get to go to the track so I don't care about MPH and ET. I just want that big smile on my face when I'm kickin some LS1 A$$ light to light.

 

The specs are:


COMP Xtreme Retrofit HYD roller

XR276HR-10

.502int/.510exh
224/230 dur @.050
110LSA
106 Int centerline

 

You'll know instantly because the next dyno run, you'll have more HP & TQ. Generally, richer than 12.4 starts to rob power as does leaner than 12.8. Being leaner than optimum will cost more than being richer than optimum.

As for spark, the key is knock retard and whether it too is adding more power. Some engines can start detonating as early as 26* some may not detonate with 40+*. Detontation is to be avoided at all cost.

Now, assuming you DON'T have any detonation problem, the next question is whether the engine likes more timing or doesn't. Once you get your fuel within the 12.4-12.8 range, the next thing to work on is the spark.

You strive to get the spark advance in as quickly as possible without incurring detonation. By peak TQ, you should be all dialed in for spark advance though some engines like a dash more spark (with a dash more fuel) as you approach peak HP.

And always remember that if you add more spark, you will lean the mixture and may need to add a dash more fuel.

But the main goal with the spark is to find the lowest number that produces the maximum HP (or as near) with no detonation. If you produce noticeable more power at 36* with no detonation, then your spark advance is 36*. If you produce little or no extra HP at 36* (but still no detonation), then there is no advantage to using 36* over 32*.

Generally, few engines produce more HP with their spark advanced beyond 36* (but there is always an exception) as there are some engines that just cannot tolerate more than 26* of spark advance.

This is truly one of those areas where you need to play with it and see what your motor likes. So there is no "magic" number for what your spark advance should be or that can be generalized. About the only thing that can be generalized is to try and get your spark advance dialed in as quickly as possible without incurring detonation.

 

Thanks for the specs. That was similar to what I figured it would be. Too much .050 duration for me, and 110 LSA.
Sounds like your combo ought to scream, tho.

 

That's about what I'm running in .050 duration but with a tad more duration once you factor in the 1.6 RRs and a bit more valve lift. I had mine ground on 114s though.

I chose not to go for more duration also, in order to keep the around-town manners in check.

Jake

 

Mine is ok around town really. I wish I would have went with 112lsa now ....just to keep a little more bottom end. But driving it around, youd never know the difference Turns out my engine only likes about 28* total timing, not 32 as previously thought. The engine just seems to idle so much better with 28 * total and 10 deg base timing. Im hoping to get my VE tables figured out although they are much better. Has anybody had any experience with VEmaster? IM thinking of trying it once I get the numbers closer.......any thoughts?

 

I run a VERY similar cam in my 355 ci .

My specs:

Hyd/roller CC xtreme 8-503-8

.503/.510
224/230 @ .050
112 LSA
108 ICA

It's an AWESOME cam!


By the way, are you Speed density or MAF?

 

Im speed density. I thought about converting to MAF making it easier to tune....but decided not to have extra parts that could potentially cause more problems. I love the way my cam sounds...its a racey, lopey idle sort of. Sounds like my dads old 396 Chevelle.. How well does that cam work for the 355??? is it a 112 lsa? I actually wanted to go bigger for mine, because my original plan was to build a stroker 420ci monster. BUT, that would have been even harder to tune....

 

My cam sounds AWESOME in my 355 ! Nice choppy almost solid roller type idle sound, it sounds pro-stock open header!!

Yes, my cam has a 112 LSA.

Keep in mind that the same cam of any size will sound meaner in a smaller displacement motor. The more cubes, the more tame the cam becomes. At least thats been my experience with motors and cams !

And yea, I'm STILL tuning on the ECM !! I still have a ways to go!

 

Yeah I know about the cam size being meaner with less cubes. I was curious about how your car sounds with a similar cam. If mine sounds mean, I know your's does!! I have the same exhaust (Hooker LT's, Mufflex Ypipe) but with a Dynomax ultra flo muffler.....and it sounds wicked. I know my cam has a bit more overlap because of the 110LSA, but it works out with my big heads...and more ci.....Good luck with the tuning!!! Ill keep trying also......

 

a hsr will make alot more hp

 

a hsr will make alot more hp...

But at the expense of higher RPMs...
THe HSR appears to be an excellent induction system, but I ruled it out for me because of the RPMs I will use on the street won't justify the need for it.

 

Someone correct me here, I always thought 1.6 rockers only added lift, not duration???

 

I have a 406 so I have too much torque vs hp, so the HSR is perfect for me. Not to mention the hsr is an idle to 6000rpm intake, chech the holley site. I thought it was a high rpm intake but holley told me(on the phone) the runner length is suited for idle to 6000rpms.

 

How could you ever have too much torque vs hp? Unless you were in a 2000lb car, Id say thats impossible. Thats how old full bodied Nova's and Chevelle's run so well with heavy BBC's. They have GOBS of torque, and usually dont have to rev the **** outta the motor. I love my LTR setup, and personally I wouldnt trade it for the HSR now that Ive seen how flat my torque curve is. I might gain 20-30hp on my setup with it, but at the expense of 40ft lbs down "low" on torque. Thats not worth it to me....but its just my .02.

 

check my 383 thread. That car has more torque than hp, it even has a miniram.That engine has a flat torque curve to boot. I'm not disagreeing with you. But if you have 500+lbs of torque at idle, it's a little hard to harness. Even with the HSR and fat cam I should dyno at least 350 rwhp from about 2500rpms and up. My car weighs 3300lbs so torque is not as important that say a nova.BTW, I also love the TPI intake . I will miss it alot. At least my 86 is a tpi

 

Good point about the 500ft lbs being hard to harness..... Im not downing the HSR, Im just a fan of the TPI intake. Plus, I got such a great deal on the siamesed intake, I couldnt pass it up

 

i knew youd keep the TPI...

that much power it would be hard not to...like u said, you maybe 30 on top but youll be waiting and waiting for the power to come on..with the TPI its on like right now...and since its makes so much grunt you dont ned to rev it...
where are u gonna shift at?

 

This discussion comes up several times a year and on other boards too.

I believe the main point of disagreement deals with defining one's terms.

The duration of the camshaft does not change. If you remove the camshaft from the engine and measure it, it'll be the same as when you first installed it.

Duration at the VALVE, however, does increase on the order of 2 to 3 degrees@ .050. This will vary depending on the aggressiveness of the ramps on the camshaft. The more aggressive the ramps, the more the duration will increase.

Periodically - and even in a recent magazine article - tests were done to measure exactly how much duration increases AT THE VALVE - with comparing different rocker arm ratios.

When comparing 1.5 with 1.6 rockers, at virtually every point of lobe lift, valve duration is greater. So installing higher ratio rockers not only increases lift, but duration as well.

Of course, there are those who will continually argue the opposite, but the camshaft companies as well as testing done by the many mags who have investigated this all conclude duration does increase, albeit only a few degrees.

Hope this helps.

Jake

 

Remember, most camshaft companies state the .050 & lift WITH 1.5 rockers and based on it's effect on the cam. In all honesty, this too is at the valve because if you compared it to 1:1, it would be different again.

So the critics that say "the cam is still the same", the answer is no because you aren't using 1:1 either, which is the REAL cam lobes.

1.6rrs result in increased lift and increased duration versus 1.5rrs as 1.5s are NOT the true cam specs either - it's just that the most cam companies for SBCs state the EFFECTIVE .050 lift and duration WITH 1.5rrs. The cam companies could easily state the .050 lift and duration for 1.6 RRs if they wanted 1.6 to be the standard.

 

well lets have everyone run 1.6 so its always apples to apples? what do ya think?? lol

Sorry didnt mean to hi-jack the topic, I just wanted to know

 

Very nice! With peak power at 5k you could run stock gears.
Nice with such a mild cam too.

Looking at your spec list, is that GMPP crank an iron piece? Nodular or?

 

Its a "1053" steel piece. I have the part number wrote down somewhere....but Im sure its still in the GMPP catalog......

 

i like your set up,very complimenting combo.bigger c.i. =less rpm cause the tq is off the chain,i know you love the feeling of your body blasting the seat ...i have the 286hr 10. 230@.050 560 on a 110*..........

 

So you can hear your lifters?? Maybe you need to ajust them since yours arent really solid lifters just poking some fun

 

Oh, I didn't know GMPP offered a steel 3.75" crank. Cool!