Guest

So I finally got dyno results. I can already hear the opinions and criticisms, so... speak but like in the Conseco commercial "I cant hear you."

Anyway here's the deal. I decided to do something totally unusual, and siamese part of the runner lengths in the base, more specifically the 2 that are next to one another. I cut down 5" into the base totally taking out the wall between the 2 runners aside from areas the casting prohibited me from cutting. An aftermarket base like the Edelbrock or Accel would allow a completely oval hole rather than the silly sunglasses style I have now. I guess you should see what it looks like first. I only have these 2 pics. I took some of the manifold after I took it off the TA to put on the Grand Prix and... damn cameras... the stupid film wasnt in right and didnt advance . So for now, these are the only 2 I have

Doesnt look like much does it? At least not on this side. As you can see, I did port the openings going to the head side. These pics were taken sometime inbetween start and finish, so there was more grinding done after these were taken.

This shows more what I did. I rounded the area between the 2 runners better than what you see here, and did some more grinding around the entries to take out the stupid rolled edge that there is stock.

Ok, what am I comparing here? Heres the deal:
Start;
Stock 88TPI intake from the TB to the base, totally untouched cept for some dents in the runners I attempted to fix.
Finish;
85 TPI base, siamesed. The rest, including everything else on the engine (that includes timing, fuel, etc) are the same as the first test.

Results?
Start;
237.0hp@4900, 266.5tq@3500. Pathetic, especially for what this car should be putting out. Came across some problems on the dyno run that I did not know of, so I will be fixing those. No, I didnt fix them yet.
Finish;
256.8hp@4860, 281.7tq@4000
Had a slight problem with this one. The first run, he let off at 4860 because it felt like it lost power as he said... So we made another run, and I heard a rocker arm clicking So I had him abort the run and didnt make a 3rd one.
We were checking out the graphs for a while, and it is readily apparent we never made it to the hp peak. I dont know how much I would have picked up if we had. The tq from where it was started to the end was never less than with the stock base either.

SOTP impressions;
The car doesnt feel as asthmatic as it did before. I didnt mess with a damn thing that has to do with the tranny (the TB never came off the plenum either, nor did the bracket) and for some reason the shift point sailed up into la-la land. Why? Dunno. It used to shift at about 6300. My dad drove the car first, and it was headed past about 6800 and went to around 7000 by the time he let off so it would shift. I didnt setup this valvetrain for more than 6000 yet, I need a rev-kit before I want to risk that one. It picked up alot of rpm here. It definitely has more power from what I can tell. The dyno graphs show it as well. Could this gain be accomplished with just porting the base? I dont know, I would assume that from what I hear you could pick up quite a bit from porting. Keep in mind I did not tune the car at all. It has a loose rocker. Its running lean (pings now past 4000). The timing could probably use to be messed with as well. I didnt get as good of results as I had hoped (I was honestly looking for 30HP) but then again the second test was far from ideal unfortunately.

Is this for you? Good question. I had the manifold on my TA first with the old tired, cracked block 86 engine with a small cam, and it definitely helped. I then replaced the POS 86 engine with a 91, has the 'good' cam and threw the manifold on there. It felt good, felt cam limited not manifold limited. Now its back to a stock base, and it doesnt feel any faster.. or slower for that matter. I am going to gtech it later today (I know, but its the same gtech, same road, and I have lots of previous runs) and see what sorta times it turns now. My initial instinct would be to say if your engine is stock or has a mild cam, dont even think about it. For those of us with engines that want and need higher RPM's I think its just what the doctor ordered. The engine in the GP I had taken up to 7000 before, but even though it pulled pretty damn good for a TPI, it struggled a little. It doesnt struggle anymore. It feels much better, and from that alone I feel it was worth it and I am leaving it this way. Only thing I might do is clean it up some more, maybe take more of the wall out and see what happens.

I suppose I should tell you what engine I have in the Grand Prix. Its an 88 block, 86 vette aluminum heads (home ported) stock injectors, had a stock intake, stock MAF, stupid exhaust, headers, SLP cam (224/232 .497/.517), and 10.3 compression.

Nows your chance... post whatever you are thinking.

Oh yea... I have graphs but they are not scanned yet. Ill post those soon as I can get it done.

The ODB

throw the books out the window.
learn by doing and testing yourself.

I like it !

90Iroc

What do you use to cut the manifold with? what the hell is that on your EGR? It looks like an O2 sensor on the EGR.

deadbird

That looks like alot of work.

90iroc, It's a temp sensor.

evilho7810

That's fukin beautifull! How long did it take? And can you post more rpm hp & tq numbers. I'm taking my intake apart soon and I just may try what you did.

Kenn

I would have never figured a siamesed portion in the middle would help top end breathing and not change the low end
I like it too
good work!!

Z28ricer

iTrader: (2)

You stole my idea !, well i guess you didnt steal it cuz i didnt post it but i was going to try that on my TPI intake when i installed it but plans change and now im about to put an LT1 in, nice to know my idea would have worked.

Guest

Making this easy on myself here:
Thanks. Books? We dont need no stinking books!
Actually... I have an owners manual, does that count?

Yep, temp sensor. I used a bench mill, it was relatively inexpensive but is 3 axis and works for what I need. With the right equipment its not so bad. Dont even try this with a dremel, I had huge piles of aluminum from cutting... and the manifold is considerably lighter now.

See above. Wasnt too bad.

I think I have about 8-10 hours in it. I am planning on scanning the dyno graphs, but this is turning out to be a really bad week and my scanner is in a box right now. Chances are it would end up resulting in no scans, broken glass, and a scanner laying on the front lawn. I will get it done soon enough though. I posted on tech about tq, heres what I posted:
Torque... well at 3200rpm I now have 260, and before at 3200 I had 248. I dont have numbers for anything below that, but SOTP I would say its less at some point for sure. Past 3000 its more all the way up. At the previous peak it was 266, now its 272@3500. At 4000 before it was 261, now its 282.
I can give you some more info on the hp if you would like, you can email me or whatever. I am kinda pissed we had to abort the second run and skip the third due to the loose rocker, but such is life. The numbers are still impressive to me anyway. Lemme know how much time you got and Ill do what I can to get you the info before then.

Thanks Kenn.

Kenn

So you loose a little torque below 3K and get the long runner set-up to rev up to 7K - starting from a smaller cut-out you could probably cut and tune to get the best of both -

As opposed to siamesing the top of the runner this way seems to give the air column a way to ram its way to the adjacent cylinder and not choke up the top half of the runner- I'll definitely try this before spending for a different induction setup altogether- keep us posted -I'm not in a hurry
good luck

Ski89Z28

madmax,
This thread just amazes me so much that I've read this like 20 times!
The one thing that worries me is the engine reving to 7000rpms till it wants to shift, please keep us informed on this. But like Kenn said if you only siamese the runners say like 3 inches would that have any affect on the shift point?
Also now that you did this are you going to do any custom chip tuning?
Well, thanks for the R&D work and I look forward to gtech info when you get it.
Pleaes keep us informed cause I think I'll try this mod come summer.

F22Raptor

90iroc, you really craked me up when you asked "what the hell is that? it looks like an oxygen sensor" It just made me laugh a lot. To be honest, I didn't know what it was either, it's just funny the way you asked.

About the base mod, MAN, and my mechanic though I was crazy when I cut 2.5 inches off the top and bottom divider wall on my SLP runners!!By the way, I also though about doing what madmax did, but maybe just 1-1.5 inches; time however did not permit.
I wonder what would happen with my ported SLP runners?
Thanks for having the ballz madmax. Not many people are as "crazy" as we are.
Rick

ps: I called myself crazy because back in '94 I did my crazy mod against my mechanic's advice. Also put a cutout right before the catalytic converter; I was told I would loose all my torque. Turned out to be the opposite.Never regretted doing what I did.

------------------
'88 GTA 350
Headers, catback, free mods, Xtreme energy cam, intake pieces and 2100 RPM TQ

13.39@102.50 MPH
1.90 Sec ------- Best 60FT
104.23 MPH -- Best Trap Speed
AIM HIGH!

The ODB

Rick,
did you ever consider that you might be running too rich at full throttle at your lower RPM's?
That would explain two things I see with your car. One is that you feel no loss in torque when uncapped before the cat. Two is that your ideal E.T. for 104.2mph should be closer to 13.0
or 13.2 for 102.
TPI cars have a tendency to run right on their ideal E.T. even with less than optimal 60' times, because they are so heavy on torque VS horsepower. As a reference, when my own TPI car was running at the lean limit for maximum power, I would always run at least one tenth quicker than my ideal E.T. for the trap speed I was getting.

For example a typical run for me might be 12.92 @ 102mph with 1.9 60' times.


just something to think about.

[This message has been edited by The ODB (edited February 25, 2001).]

90Iroc

Thanks F22 Raptor! I don't know a whole lot still, but every day I'm learning. I'm in the process of rebuild talks with my dad. The LB9 that currently resides in my Iroc is leaking antifreeze from the passenger side cylinder head at the gasket by cylinder #8. So I'm going to ask him about throwing in a 350. I don't know if he's going to go for it, he and my mom are big on keeping it stock. They won't even let me put in a six speed, even though my car is chewing up the "world class" T5 in it now. This makes two times now that the tranny will have to be rebuilt. Even though the T56 is stonger and can handle the torque, they won't let me because it won't be stock and I'll be "ruining" the value of the car. We'll see.

leirch

90iroc,
Stock? yea i'd say keep it stock like the rest of us.
Ok...maybe not

Brendan

------------------
1987 IROC-Z L98,SuperRam,EB 6085's,LPE 219/219 Roller, Crane 1.6RR, EB TPI Base, 58mm TB, ADS 24#, AFPR, K&N, EB TES, Catco Cat, 3" Borla Cat-Back, Accel cap,rotor,distro/other crap, MSD 6AL, MSD Blaster 3, Aluminum DS, 94 Disk Rear, Adjustable Valve, Precision 3.73 Gears, Sub-Frame Connectors, Hotchkis Lower Control Arms, KYB Shocks/Struts, Suspension Techniques Lowering Springs, Polyurethan Bushings all over the place, Moog Upper/Lower Ball joints and Tie Rods ends/Idler Arm,

To see the ROC, Check out the webpage Here

F22Raptor

Posted by ODB:
I am running rich ODB! When I hook up my scanner, the O2 sensor reads 950mv. According to the people here, you want to be at around 850mv or so.
The rich condition is more obvious at idle. That's when the car really stinks, but I think prom tunning is the only way to fix it.
As fas as the ET times, I know I can do better than that. I have been to the track twice, and both times the wind was almost unbaerable and right head on. This adds at least one tenth to my times. I'll be going soo, maybe next month. Will lower fuel pressure, set timing to 6-7* and replace the fuel line going into the base that I bent and kinked. Wish me luck
Rick.

IROCKZ4me

Good looking job.
I've done a few like this myself. Basicaly what you have done is increase the volume of the plenum (the area inside the runners and the siamesed part of the base), and shortened the intake ports to near the same length as a Mini Ram.
You can create a hell of a sleeper that way. You wouldn't believe the number of guys that would say "that thing couldn't make power with that restrictive TPI manifold on there". Then they get dusted and just can't understand it. LOL. It really kills them when they ride in the car done this way and you're revving past 7000 RPM and it's still pulling. LOL. If you want to really confuse some people build an internaly balanced 406 shortblock and keep it all stock looking and slip it under that intake.

The problem with your shift points may be caused by your TV cable being pulled out of adjustment when you R&Rd the plenum. Have you checked that?
The porting itself wouldn't have anything to do with the RPM at which the transmission shifts itself. That is controled by trannie fluid pressure, the TV cable, and the govenor.


------------------

Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

My IROC-Z
EFI Performance Club on Yahoo
Club IROC-Z


[This message has been edited by IROCKZ4me (edited February 28, 2001).]

90Iroc

I hate getting off topic, but my parents have "let" me do things like exhaust and chip and fuel pressure regulator. They just don't see me doing them. The exhaust they knew about though. I wish I had the resources available to do things like you all are takling about here. I was going to cut down the little "wall" behind the throttle butterflies when I do this rebuild. I wish I knew and had the tools to do all this other stuff too!

jmd

iTrader: (4)

I see nothing wrong w/ this at all; I think you've done a very cool thing.

Question... how long are the base runners? I figure if you look at an LT1 manifold, which I think has around 3" runners and a fairly enormous "plenum" area... and LT1 guys don't complain about loss of torque

90Iroc

I'm back again. Can anyone tell me which bit to use on a Dremel to cut the wall behind the butterflies? I've never actually used the Dremel, just sort of played around with it Can you describe the bit to me?

Guest

Tracy;

Yea, I checked the TV cable. I actually have it marked and it was in the same spot. I didnt take the bracket or TB off the plenum, so I'm a little confused as to why it changed too. I remember reading a trans article a while back and it said something about engine acceleration and shift points, so... I dunno. Maybe the converter is slipping.

I scanned the dyno sheets. I should have a graph in a couple days or less (depends on what sorta time I have) with both curves on it so the difference is easier to see. I'll probably have that done later today though. These arent exact as they are, the rpm range is a little different, and the hp and tq scales arent in the same spots. The first one is before the manifold, the second after.

88 350 tpi formula

iTrader: (9)

I have a spare 88 intake I may do that too. I thoght of buying the slp runners and making them open all the way down. I wonder how many r's you could get doing both.

Guest

I know this is gonna make the screen scroll for some of ya...



Take a look at what happens past 4800 rpm...

[This message has been edited by madmax (edited February 28, 2001).]

IROCKZ4me

That baffles me then about the shift points. I have done this kind of mod on different cars and it didn't affect shift points like this. I'm very curious about what is causing that now if it isn't the TV valve or cable. Are the shift RPMs high at part throttle too, or just at heavy/WO throttle?

<hr>
88 350 tpi formula, that is one of my favorite intake combos. With the right heads & cam you can make power through 7200 RPM (or more) and spin over 7500 RPM. The main limiting factors would be head port volume (high RPM flow) & cam duration.

You could spin faster with an exceptional set of heads & cam. You would probably need to start with an aftermarket manifold or at least a welded up stock manifold (material added to the top) & then port like this to get the port width needed to make power past 7500 RPM.


------------------

Tracy /AKA IROCKZ4me
'86 IROC-Z Camaro
"Cogito ergo zoom"

• 355 cid
• AFR heads
• Arizona Speed & Marine hydraulic roller cam w/ AFR hydra-rev kit
• modified SLP runners
• TRW forged pistons/ceramic coated
• fully balanced
• Edelbrock headers/ceramic coated
• SLP cat-back
• Paxton supercharger
• Nitrous Express nitrous oxide

My IROC-Z
EFI Performance Club on Yahoo
Club IROC-Z


[This message has been edited by IROCKZ4me (edited March 01, 2001).]

Ski89Z28

AMAZING!
I just love pictures!
madmax, as you stated earlier if you were able to go higher reving it looks like the HP and maybe the torque may have gone higher too?
Question:
Does anyone know what and aftermarket intake would let the engine rev to?
Also gains in HP and Torque for it?

All in all this mod may be the missing link for the thirdgens to obtain higher HP with higher torque like the LS1 engines.
Looks like I'll be taking off my intake and doing alot of grinding.

Jon88GTA

Hey madmax...what kind of runners are you using? If the intake from the base up is completely siamesed, then all you've done is created a really short-runner intake, very much like the LT1 or Mini-Ram. If, however, there is still a divider in the runners, then you have created a wonder of acoustics. Basically, what you've got a is a tuned-port system with TWO resonance points--i.e., you've still got the long-tube setup in place, which boosts low end, but siamesing the base has also created a 'virtual' short-runner setup, which boosts high-RPM power...without affecting the low end! I'd never even thought of doing this...I'm not sure if anyone else sees the genius behind this idea. Even if you're using siamesed runners and I'm just out in la-la land with all this stuff...I'm gonna play with this and see what happens. And may you rot in hell if you steal this idea from me.

Guest

Revived from the dead... lol

Stock runners , dents included. Tomorrow I am taking off the plenum and grinding down the EGR walls and opening up the holes for a 52mm TB. Maybe I'll port match the plenum to the runners too... heh.

Last weekend after a car show, the GP was lined up next to a new vette at a light. Was real close but even up to 115, the GP was in front
The exhaust is pretty bad, sounds like an old caddy or other big block boat past 2000, no engine sound just rushing air. How did I know that? Was in my TA next to the GP at the light, had no chance at all keeping up with those 2. I figure theres about 30hp trapped up in the exhaust at least, maybe more.

F22Raptor

Madmax, what heads are you using? No headers?
Thanks, Rick

Guest

Ported vette aluminum heads, and 1 5/8" headers. Not much out there in the way of shorty headers for a G-body. I might be getting some SLP's for my TA, gonna see if those fit the GP.
I should add... if you saw the y-pipe, you would know why the exhaust sucks. Thats getting fixed in the next month or so.

I have info on my website about the car, at http://home.earthlink.net/~madmax0

[This message has been edited by madmax (edited March 26, 2001).]

88blkiroc

man, this is some pretty cool stuff. does anyone sell a base like this? I dont have the equipment to do it myself nor do i have a spare intake to **** with, but for the kinda gains you got, this sounds like a really cool idea. What would be the best size intake runner in a head to match a setup with a base like this, stock runners, ported plenum, and 52mm TB? Also, could you do this to a TPIS Big Mouth or similar intake and expect even more power? Also, how about running Large tube runners? sorry if these are dumb questions, but im trying to learn at least

SINNIM

YOU THE MAN! But I have a question about the whole thing and if I can get away with it, it will be done. I unfortunately have to deal with emissions in my 91Z28. If I did it am I going to get away with passing a smog test? I plan on rebuilding and doing mods soon. The bad thing is that I have to do extra thinking because of of this non powerless state that everybody thinks is so awesome to live in. Yes California. Bah Humbug! From what I have read I wouldn't be able to get away with a mini ram which I had planned on getting because the emission level would be out of wack. So I guess I'm looking for a yes or no answer to stay on the subject and if I can how do I go about it? Thanks in advance!

superz

hey madmax, just trying to get stuff straight here, u r runnin stock runners, stock unported plenum, vette heads, and decent exhaust? basically all u did was put on vette heads and siamese the base and got 15 horse and 25 ftlb of torque with the base alone, right? why can't u get a bigmouth base and port it that way? now that would flow!!

Guest

88, I think that the stock runners with a ported plenum and a 52mm tb are probably a good choice. I did this as an experiment, and to try and keep costs down. I dont know of anyone who sells something like this, so you are on your own there. With an aftermarket base it would probably work better, there wouldnt be any separation between the runners left at all, unlike how it is now. But then again, that costs more money.

Sinnim, I am in Cali too. I cant see how it would effect emissions, and there isnt any smog tech in his right mind who would even think this has been done, or who would take apart the intake to check. They just look for external stuff, and stick the sniffer in the pipe. I wouldnt worry about it.

superz
"u r runnin stock runners, stock unported plenum, vette heads, and decent exhaust?"
Yes, except the decent exhaust part(and a stock tb as well). I am not happy with the current setup. And the only thing I changed here was the intake base from the stock base to the siamesed one.

[This message has been edited by madmax (edited March 28, 2001).]

DownUnderIROC

Great job Mad Max, you shoulda been an Aussie mate We come up with **** like that all the time

If I can find a spare intake base here, I am going to try your siamesed mod.

Good job mate.

------------------
1987 Chevy Camaro IROC-Z. 305 TPI. 700R4
14.6 secs @ 93 MPH.
2.14 sixty foot.
Nitrous soon! :-)
http://www.camaro-firebird.org
Camaro and Firebird pages in Sydney, Australia.

NavyVette

MadMax, What is the part number on that intake you have? It looks like the spare I have here at home.

Jeff

86TpiTransAm

This is just so good I had to bring it back up to the top!

For those of you askin' about doin' this to a Big Mouth Manifold! I'm sure it'd probably work great! But here's my question for you..... would you REALLY wanna spend $425 on an intake and then go to do this and then "accidentally" destroy the new intake you just spent all that money on!! I'd say unless you've done this several times I wouldn't risk it on the Big Mouth!!

MADMAX: You might not recommend doin' this with a dremel....but by god I'm gonna do it with my dremel even if it takes me days and tons of dremel tools!! LOL! I work with what I've got!!

Guest

Navy, good question. Its a stock TPI base off an 85 F-body. I'll have to look later to see what the number is.

Rob P

iTrader: (1)

Has anyone else done this and dyno'd it yet? I am looking for a cheap used stock intake to do this to and put it on my 305TPI 92Z28convt. I have a dyno sheet on it so I have a baseline. Kinda scared to do it to my ZZ4TPI with the $400 Edelbrock Hi-FLow and who knows what would happen with the SLP runners I have

------------------
Rob P
89RSconvtZZ4TPI
Edelbrock Hi-Flow Intake
SLP Dual Cold Air Intake
1 5/8" Headers
Semi-Siamesed Runners
MSD6AL/relocated MAT/ AdjFPR/IROC frnt@rear swaybar/wonderbar/steeringbox/alum drvshaft/ Alston SFC/3:23posi disc rear/MAC LCA/H.Adams Panhard Rod/KYB struts/ shocks/
92Z28convt5spd
71Impala convt 402BB
BETTER DRIVING THRU SUPERIOR HORSEPOWER!

90 Z28SS

My base is about done . I'm just cleaning up the runner sections now with a die grinder . I wont have dyno #'s , but I should have some real world 1/4 #'s by next Sunday of what I gained off it . I'm most interested in 3rd gear results Just for the hell of it and because I have one , I'm putting a stock 95 LT1 cam to help out "a little" better than the stocker BL2 cam would .

Thanx for the idea Madmax . I went 13.16 couple weeks ago , this may bump me in the 12's for free

------------------
Derek 90 IROC 5.7[/i]
Mods: All the usual bolt ons , 2500 stall , 373's , SS hood , lotta reduced weight.
Best Et: 13.16@101

The Man

one hell of a job! I would love to see what type of improvements above 5000rpm's. when do you think you will be back on the dyno? how much reduction in your 1/4 times? Feel like doing another one?;-)

91DropTopTA

I just want to say that this is probably one of the best threads I've seen. I've seen a lot of whining and flaming, but this post is pure gear head grease monkey stuff. That's what it's all about.

F22Raptor

I agree

F22Raptor

I will definately do this as soon as my new house with my new garage is done
Rick

86TpiTransAm

Pictures....I wanna see pictures of the work you did on your intake! I'm sure it looks like Madmax's work but I wanna see anyway!

TRAXION

Just wanted to make a quick post on this subject. I know Mike will 'love me' (not!) for sending so many hits to his page but you have to check out what he has done. In his Winter Mods section he has many dyno runs and pictures comparing various intake modifications.

I lent him my MiniRam and he did a direct comparison between a fully upgraded TPI intake as compared to the MiniRam (on a ZZ4 with HOT cam!). Then he bolted a set of AFR190s on and has dyno runs of that. Next, he is installing the siamesed bottom intake and will be dyno testing that! Very very cool. If you want to see pics of Mike's siamesed Edelbrock H-Flow base then check out these websites in addition to the main winter mod link already posted above...

http://www.eecis.udel.edu/~davis/z28...16siamesebase/
and here...
http://www.eecis.udel.edu/~davis/z28...sebaseporting/

All in all he will have the following dyno comparisons...
1) ZZ4 with Hot Cam and fully upgraded / ported TPI intake (ported Edelbrock Hi-Flow base, AS&M LTRs, ported plenum, 58mm TB)
2) Same as #1 except TPIS MiniRam in place of the TPI.
3) Same as #1 except Airflow Research 190cc heads in replace of the ZZ4 heads.
4) Same as #3 except with the siamesed Edelbrock hi-flow base.

Very cool stuff.

Tim

------------------
TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

Ski89Z28

Tim,
That is a great link and the info will be great when done. However when Mike siamesed the Edelbrock hi-flow base he only went like 2.5 inches and Max went like 5 inches. Was there some logic as to why Mike went 2.5 inches? Is he leaving room to siamese them later to 5 inches?
My only concern is that if Mike doesn't get the same or better results as Max it doesn't mean that siamese intakes aren't good since it isn't the same test. As Jon88GTA pointed out that basically Max created a tuned-port-system with TWO resonance points. So will the length of the runners in the intake have an affect?
I'm no engineer but if there is a resonance point inside the siamesed intake, the amount of material left in there separating it may be the deciding factor. Max may have hit the magic number for it and then again maybe not.
I can't wait till Mike puts the HI-FLO siamese base on and does the runs.
Thanks,
Ski

TRAXION

The way that Mike is doing this is definitely a very good approach. You don't want to remove more than you have to. If he needs to remove more ... he can Basically, he made it such that one base intake runner can reap the benefits of breathing through 2 Large Tube Runners. The results should definitely be interesting.

Tim

------------------
TRAXION's 1990 IROC-Z
Best Time = 12.244 @ 112.51mph (1.778 60' / 7.819@88.32mph in the 1/8)
All Natural. No Force. No Drugs. Stock Bottom End. Stock Body Panels.
Gunning for NA 11's with bigger cam, bigger stall, and bigger exhaust.
-=ICON Motorsports=-
Moderator: PROM board at thirdgen.org

John Millican

iTrader: (1)

I found a quick way to remove 1 1/2", I'm still undecided to make it deeper or not. It's only done one one side and I still have to blend it but it only took 1 hour.







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86 Camaro Sport
383 Speed-O-Motive Crate Engine, Raptor 700R4 Tranmission, Trick Flow Twisted Wedge G2's, 58mm Accel TB, 3.73 Auburn Pro, SLP Cold Air Induction and Headers, Dynomax Cat-back, Serpentine Belt Setup, Dual IROC Fans, Jamex springs, 16" IROC Rims, 36mm/24mm Sway Bars, Global West Steering Brace. Hotchkis Rear LCA's,Panhard Bar and SFC's.
My Camaro Project



[This message has been edited by John Millican (edited May 03, 2001).]

FSTFBDY

iTrader: (33)

Bttt ,

Since Im doing one for a buddy with a ZZ4 I thought id just bring it up again.

JakeJr

You guys inspired me.

I'm doing mine now too. Running a stock plenum which had the restrictions directly behind the TB removed 2 years ago, SLP big tube runners and stock manifold base.

I spent the last two days doing the plenum and the SLP big tube runners.

For those not familar with those runners, they come with the dividing walls on two tubes on each runner set partially removed. I extended the wall removal as far as I could reach, which ended up to be a total of 2-1/4" (so far)from the mounting flange; shaped sorta like a "V".

I then removed 1-1/4" (so far)from the dividing walls at the manifold base end of the tubes. This is a far as I could reach before the runner made a bend which prevent me from getting in farther.

The walls remaining in the runners should be about 6 to 6-1/2" in length now. I forgot to take a measurement but I will today.

So plenum end has the walls removed to a depth of 2-1/4" and the manifold end has the walls removed to a depth of 1-1/4". I'm goning to grind on them some more to try to get a bit more since I'm running a 415.

I also noticed that the plenum end diameters are slightly larger than the manifold end diameters. I'm guessing this is to create a funnel effect.

Today I'll pull the manifold itself and begin the removal of the dividing walls on it. I'm going to remove the walls in the manifold as far in as I can reach.

I've been using a reciprocating saw (SawZall) with a metal cutting blade, then carbide bits of different shapes, etc in my Mikita high speed grinder.

Have to stop every hour of so to sweep away all the metal shavings from the workbench and floor.

I learned from a guy who use to work for Extrude Hone and has done lots of work on the stock TPI setup and he said make the diameter 1-3/4".

Hope to have it all back together Thursday.

Sorry I don't have any photos and performance will be seat-of-the-pants.

What grit sanding rolls did you guys use to smooth out the runner surfaces? What's the best way to enlarge the gaskets to make sure they don't overlap the larger diameter holes? Since the gaskets have a metal center, they are not easy to cut with sissors.

BTW, Hey MadMax: Surprising how well your mod caught on isn't it? And to think, you suspected you'd be getting all kinds of criticism for doing it.

Thanks,

Jake


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1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9



[This message has been edited by JakeJr (edited May 09, 2001).]

85MikeTPI

iTrader: (2)

As for TPI gaskets, you can get the Accel
hi-flow gasket set which are already ported
to 1.75" tubes ($39), or buy the raw gasket
stock from Accel and make them yourself.
(no metal core in the gaskets)

Jegs P/N for both are:

310-74195G for the pre-made set ($39)
720-77C for the raw stock ($7.50)

I was able to make a complete set of runner
gaskets (upper and lower) from one of the
raw stock sheets. It cuts easily with a
fresh razorblade knife.

mike


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My Z28, ZZ4swap, TPI EPROMs