That will definitely help

 

FMS, nice work on the intake and throttle body to get them flowing that much!

Allen used the FIRST base on his build along with modified SLP runners that looked a lot like what you’re doing to your FIRST’s runners. Pretty sure I remember him saying that when they tested the modified runners on the intake the flow didn’t change – so I’d suspect you won’t see any drop in flow with your runners attached either. I’m not sure if he tested it with the plenum attached through (it would have been a stock TPI plenum anyway). However, it sounds like you’re doing some plenum welding and modifying - so, I suspect that along with opening it up to match the siamesed runners you won’t lose much if any flow there either.

 

my hemi... The machine shop I used bored the throttle body to 76mm and made a custom throttle body blade. They also milled 2mm off the throttle blade shaft where it attaches to the blade. Then I started grinding and polishing on the throttle body to smooth and blend in entry and exit venturi. I removed a lot of material (started with a carbide cutter) to smooth and blend the entry and exit. When I finished, I was at 77.2 mm for the main bore. I also used counter-sunk machine screws to attach the throttle body blade to help with the flow. This process took a while and we flow benched the throttle body at least 5 times while making these changes. We found a lot of turbulence around the throttle body shaft even after milling it 2mm. So the last change I made was to add JB Weld to make a ramp before and after the throttle body shaft to smooth that transition and we picked up good amount of cfm from that modification.

 

Any updates on dragstrip times?

 

We are going Sunday I'll let you know!!

 

yup, my hemi and I were both planning on going to teh track tonight for TnT but right around mid afternoon (after I was fully packed and ready to go) he texted me and informed me that they were canceling TnT at the dragstrip tonight because of impending foggy weather conditions. I was super bummed out as I am sure he was too. I think we both plan on going this sunday though.

 

Glad I caught you before you left...lol your really would have been bummed sitting there lol

Sunday looks like a go for us.

 

Best of luck to both of you.

 

Thank you!

 

you are very right! I did check the website around 11 am and signed the digital NHRA covid waiver, and was super ready to hit the road. Glad you got to me in time, or else I would have really been bummed indeed!

I think I am going to also go on Sunday .

 

Nice be cool to meet you and hang out!

 

It'd be a great race to get a video of.

 

I was thinking that same thing! I am not too good at camera angles or vide stuff, but I do have a GoPro and would love an action video of my car going down the track filmed from a car in the other lane!

 

That would be cool. But the question would be, is that camera forward facing or rearward...?
It would be a close race that could be won or lost by reaction time!

 

one thing about my wife she is super competitive and she cuts a mean light!!! Like .001 time. 030 reaction times..once she figures this car out I think she'll do real good in bracket racing.

 

Ok just an update we did not go racing today hopefully will we get to the track before it closes stay tuned for updates!

 

not to worry. I was hoping to get some cool video of both of us going down the track side by side, but its ok. possibly next year.

I will carve out time soon to update my build thread with photos, videos, and datalogs. maybe 2 days from now

 

Definitely next year for sure!

We might try this Sunday if the weather holds out.

 

I've also got a FIRST intake; what TB did you go with?

Adam

 

I almost hate to say it, but if you would've sent the throttle body back to Ken @ First, he'd port it and put a new throttle body blade in and send it back to you for round-trip shipping costs. (I think he quotes 1020 or 1050 CFM with his ported version of the throttle body.

Adam

 

I agree AFR 210s, 408 cubes, solid roller, expensive valve train, ported out FIRST and MAYBE, but how you'd ever put the torque to the ground to make use of it, I'm not sure. Tank tracks? ;-)


Adam

 

it has the his 71mm on it now I had him port one to 76 mm it did run so well had idling issues so I went back to the standard one much better now.

 

stock ECU or aftermarket EFI?


adam

 

Throttle body looks spectacular! I just smoothed mine with sandpaper flapper wheels before getting it ceramic coated.




I’m going to guess with a big *** bellmouth like this you’d get a good jump in CFM. I accidentally bought two of them, too so I have a brand new one still wrapped up if you want to try it.


Adam

 

It has a holley hp efi system and a holley dual sync distributor sequential firing order.

 

why would it have idle issues? You may need alot more tune work

imo a single 76mm is kinda on the small side for a higher hp motor. Might be ok in your power range. A stock ls1 rated at 330-350 flywheel hp uses a single 78mm throttle. Bolt on ls1 with a bigger intake will use a 90 mm throttle and make 340-360 whp. Cam up and its over 400.

 

It was an old TB he ported I think it had a blade problem..it was getting stuck .so I bought a brand new TB but left it stock sizing to see how the car would run which it runs way better.. I can send it back to be ported now If I like...but for now the car runs great...so I might leave it..

 

Our builds are pretty similar.

I went with Holley HP but I didn't like the cost of the dual sync vs. going with a $50 Vortec 1x cam sync sensor and the old Holley 58x crank trigger wheel and LS truck coils.

I had to grind the bottom of the vortec cam sync sensor housing to get it to clear the back runner, but other than that, it wasn't bad at all.
Holley discontinued the 58x crank trigger wheel because they're very narrow and at high rpms the wheels can slightly move out of the sensors range if you don't have them centered PERFECTLY. Lots of high RPM guys were running into problems so they now made up some BS about 58x sensors not being designed for high RPM and that a 24x wheel is way more appropriate for high rpms (really the 24x wheels are just twice as thick as the old 58x wheels). -I figured these are PERFECT for long-runner builds.

I got a set of the D581 coils which were on the C6 vettes and some trucks for $125 off of ebay. Added expense was the COP/ CNP extension harness which you DO have to crimp and wire yourself. -I want to run with a pretty hot and long duration spark so I can lean out the mixture at highway cruise for max MPG because I'm looking to double MPG from my starting point of 11mpg to at least 22mpg, too. (C3's are TERRIBLE for fuel consumption; you thirdgen F-body guys are spoiled on that front.)


Adam

 

Do you still have the 76mm ported TB? If you do and it's just going to sit on a shelf, I might be interested... (My current one is already ceramic coated and I'm also worried that if I get it ported by Ken I'll run into idle issues and just buying a 2nd TB that's already ported up eliminates both my concerns...)


Adam

 

I saw your car featured on LSXHunter's YouTube channel. Hope to see you break into the 11s this spring!

I've only got 350 cubes but Profiler 195cc heads and a bigger and more aggressive MikeJones roller cam and I'll be happy if I can match your low 12s.

Adam

 

I also think the perfect race fuel to get a bit more out of these cars on the drag strip is VP's CHP. (They claim 15-20% more HP vs pump gas; because of the 10% oxygen content.)

Designed for GM 602 or 604 roundy round crate engines so cars with 9.5:1 to 10.5:1 static CR (technically they say up to 12:1) and dynamic compression right on the edge for 93 octane NA engines. (Like most of these good TPI motors.)

-It's a more highly oxygenated version of MS109 that enhances cylinder-to-cylinder distribution (not an issue on TPI cars, but..) and a fast burn speed so I think we could get away not adjusting timing. 108.5 octane
Makes 1.5% more power vs MS109 and costs less ($85 for 5 gallons).
10% oxygen content so with the holley HP you just take your fuel table and add 4-5%, if I remember right (the VP spec sheet says).

It's pretty corrosive fuel, though and you really should run it and then fill up with regular gas; don't let a concentrated mix of it sit in your fuel system for a long time.

They also sell CHP+ which is basically the price and has 18.34% oxygen and you set the fuel map 6-8% richer vs you pump tune. -CrateInsider says it's just crazy corrosive and eats everything and they simply don't recommend it. (contains M5 methanol). -They claim 15-20 HP over pump gas for CHP+.and 5-7% more power than E85 (and with way less injector required...).

If you're chasing that 11 seconds, an extra 15-20 ft lbs through most of the curve can only help and the tune should be easy with Holley EFI.


Adam

 

Thanks for the info..
it's best was 12.2 at 110 with a 1.6x 60ft this was with a nitto 555rs this is also my wifes car her driving it..she could not launch on the 555rs she had to roll Into the throttle can see it on the data logs she never brought it up only slightly off idle. And it had a lean spike so I fixed that issue and found the knock sensor was removing timing im sure that wasnt helping on top.end...and I finally put in a new shifter plate so she can actually tell what gear she is in the car seems to be shifting at 5400 we think 5800 to 6k should help the ETs some I bought a new set of MT ET street SS drag radials for next year hoping with the new tires..timing fixed lean spike gone and her ability to shift higher in the rpm band should net her a high 11 pass...we hope...lol.

 

I had Jones spec a couple of cams for me although that was 383 CID. I'm also using Vizard's Torque Master program to develop a cam profile for the 383 as well as a 355.
Care to share what cam specs you ended up with?

 

Did you buy a license for Torque Master or get a copy when attending a conference or something?

My cam is HR70375-71360-110.
Advertised Durations (0.006"): 272/280
0.050" Durations: 227 / 228 (I'm running CompUltra ProMagnums 1.6 ratio so 0.050" durations end up about 230/232
Seat to seat durations: 280 / 284
Lift: 3.75" intake lobe = 0.600" at valve; exhaust: .360" at cam lobe; .576" at valve

110 LSA (vacuum brakes), 107 ICL ground in
IVO: 6.5, IVC 40.5, EVO 49, EVC 3.0

Mike mentioned that he would've gone with a 112 LSA if I had a stock ECU, and hinted that he would've gone tighter if I didn't need the vacuum brakes.

Reminder: I'm only on 350 cubes.

I degreed the cam in using a few different methods (my first time doing it) and it's installed straight up.
I've got 7/16" rocker studs and overkill Comp Hi-Tech 5/16" .105" thick pushrods (7.7"); also added an overkill Jomar stud girdle; I shouldn't have deflection but I won't get extra lift from any bending rocker studs, either. -I set them up to be at 90 deg geometry @ mid-lift and that might be giving up a tiny bit of lift for added durability, but I'm not 100% clear on that. (Chris Straub / Foxwell mid-lift method.)

Johnson / Scorpion retro bar short travel roller lifters.

-He scoped the exhaust duration assuming a pipemax optimized exhaust with 1 5/8" headers, and extensions optimized for max torque (long extensions); I think the exhaust duration would be higher with a less than ideal exhaust in the spec sheet.

That cam has some pretty aggressive lobes and required PAC 1219x beehives (NOT cheap!) 145# closed @ 1.800"; 349.5# @ 1.200" open (max lift); 10 deg PAC-R310 locks and retainers (28% weight reduction from going with the beehive spring and matching locks and retainers.) -He also specced out a cheaper dual spring option that I could find and share if you're interested.

The CompCams QXI lobes are the only ones that I found that are more aggressive in a hydraulic roller and I don't want to know what the springs would cost to run those.

David Vizard's formula recommends a 106.5 LSA for max HP on a 383 if you don't have to worry about the EFI system, brakes, and you don't need the extra breadth in the curve. The 383 he and Terry Walters built (and Terry Walters sells as a crate engine still) that had 538 hp and 532 ft lbs (almost 1.4 ft lbs / cube with a dual plane 383, and a 106.5 LSA and I've never seen more torque out of one, so there might be something to his LSA formula...)
-Everything I've seen says a tighter LSA is better on a 383 vs. a 350 and obviously a little bit of extra duration to keep the torque and hp peaks the same.




I did a LOT of theoretical math on this build because I enjoy it and PipeMax said if you're building a 350 and want an hp peak @ 6,000, the stock runners are great, but for a 383 you want a runner min are of 2.6"-3" and I think stock is only 2.4", so slightly porting the runners for a 383 might help hp @ 6,000 a tiny bit.

The throttle body / intake CFM and sizing calculations are all over the place, but ptoumov on ST came up with a formula to estimate hp losses from throttlebody losses and for a 450hp engine estimated a 28.3 hp loss with a 70mm throtle body (vs an "infinitely large" TB) and a 16.6hp loss for an 80mm throttle body. -I think there's probably 10-11 HP to be gained at peak HP with the 76mm ported larger throttle body around the 450 hp mark, too.

I also did a ton of head sizing calculations and for a 6,000 RPM peak hp 383 you need a 2.1 min CSA head; the AFR 195cc Comp head is 2.15", as is the Profiler 195cc head, so both are about perfect. (A 396 @ 6,000 peak wants 2.17" min CSA so the AFR 195cc comp is just about as perfect as you can get, interestingly enough.)


My combo would be better as a 383, but for now it's a 350.

Adam
P.S. My next engine math project is to estimate the relative effectiveness of the quench action of an identical CR and head gasket thickness SBC 383 vs. an SBC 396 vs a SBC 400 with a D-dish piston. The added piston speed of the 396 should make a slight increase but I think an SBC 500 with a D-dish piston will be DRAMATICALLY better and should really help keep detonation at bay in these TPI builds that are pushing the edge of detonation at the torque peak on pump gas. (I think there will be 1-2 "octane points equivalent" reduction in detonation tendencies of the 400 with D-dish pistons vs. a flat top 383 because of the turbulence introduced from the intense quench action from the big d-dish pistons.) -Faster quench also means slightly faster flame front and the potential for maybe a half to a degree less timing for a tiny bit more efficiency and torque, too.

-I also have a pet theory that piston oil squirters could REALLY help these high DCR TPI motors avoid detonation at higher CRs, too; but I can find ZERO details on how the 40-50 deg reduced piston temps impacts detonation resistance.

 

Stan Weiss (co-developer with Vizard) offered up a free trial through SpeedTalk a while back. I believe there's still a 90 day version available through Vizards website.
I used available port CFM along with valve sizes to work out a cam spec. For quick reference, a 355 with 250 CFM ports and 10.5:1 CR wanted something like a 283 single pattern (my choice) on a 108. Still plenty of vacuum for PB.
I can go through my notes for other offerings. I spec'd a 383 with the same heads and CR and the LSA tightened up to 106. Torque master targets maximum torque output and will specify peak torque and HP RPMs.