Okay, looks like I may be doing some research and dyno testing. So, please give me your thoughts: what do you think would be the best/most popular intake manifold for a B20 road race engine with stock compression (NASA H1 rules do NOT allow aftermarket pistons, so 9.6:1 is it for an 84mm bore). Yes, we're gonna tune it. Yes, we'll try 403s and 404s. Yes, it'll have a header, free flowing exhaust system and whatever injectors we need to get the job done.

Keep in mind, we're looking for a well ballanced set up, not ultimate horsepower...

 

Looking forward on seeing results. Please try a B16 IM as well as they seem to have a nice powerband below 8K compared to the ITR IM.

I have always wondered how they would do, but have never tried.


I use a Skunk2 IM right now and I am happy.

 

blox. same as skunk2 and cheaper. mill the head if youre allowed...

 

So does this mean that all the LS motor-heads haunting this thread have never tried more than one manifold? Seems like there out to be more than three guys with experience in here...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thawley &raquo;</TD></TR><TR><TD CLASS="quote">So does this mean that all the LS motor-heads haunting this thread have never tried more than one manifold? Seems like there out to be more than three guys with experience in here...</TD></TR></TABLE>

I havent tried the B16 IM, but I havent been able to get my hands on one yet surprisingly.


Bump for more responses!

 

Did you get my email? I sent it to the address listed in your profile...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thawley &raquo;</TD></TR><TR><TD CLASS="quote">Did you get my email? I sent it to the address listed in your profile...</TD></TR></TABLE>

If you sent it today then I havent gotten it, or you didnt send it to my work email. I will check my email when I get home.

 

stock ported

 

Mr. Thawley, last I checked, you have to use "stock" intake manifold on an H1 car. That is, unless you west coast guys have different rules set

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by o-man &raquo;</TD></TR><TR><TD CLASS="quote">Mr. Thawley, last I checked, you have to use "stock" intake manifold on an H1 car. That is, unless you west coast guys have different rules set </TD></TR></TABLE>
I never said anything about using it in H1. You just ASSumed that's what it's for. Second, a "stock" manifold in H1 is any IM Honda have ever made which can be adapted for use on an H1 legal engine. Third, there is no third thing, whatsoever.

Not a different rules set, just a different mind set

 

Hey dude i got a mint 1999 SI intake manifold. I was gonna put it on ebay if you want it gimme an offer.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thawley &raquo;</TD></TR><TR><TD CLASS="quote">
You just ASSumed that's what it's for. </TD></TR></TABLE>

Ouch! You are correct

May want to re-read you first post and its H1 reference

 

True, I was a bit misleading. The car is an H1 car. But its also a test mule. Any intake is legal for H1 as long as Honda made it. Modifications can only be made for fitment. But I'd rather learn what style of manifold will work best so I can avoid having to customize more than one "stock" manifold....

 

If you are asking your competitors, you will always finish behind them. YOU need to find what manifold is best. How about a P8R head? How about searching Honda pistons? How about Honda rods?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote">If you are asking your competitors, you will always finish behind them. YOU need to find what manifold is best. How about a P8R head? How about searching Honda pistons? How about Honda rods? </TD></TR></TABLE>

Well I talked to Thawley and he is said he will be testing out some cams and IM's for the B18 nonvtec. Since I am close by I asked if I could come watch or lend a hand. If he needs I have a stock P8R head.

A piston test would be nice too, however it would have to be done over time.

 

Thawley, I just threw a Skunk2 on my B18B, and the higher mid-range and top-end is WAY better. Unfortunately, that's all I can tell you. I haven't compared it to any others or anything, BUT what I understand is that the Skunk2 is like an ITR IM with an LS flange. If that's the case, I think it'd be a good bet, at least among OEM IMs.

In addition, the 403s are also very nice. The biggest concern with 404s is that you may not be able to rev as high as they're designed for. My 403s still feel strong up to 7200rpm. Given that you can't get past the LS rod bolt issue (unless you maybe use GSR/B16 rods or something?), there wouldn't be much point to using the 404s, as the powerband they're designed for wouldn't be yours.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sscguy &raquo;</TD></TR><TR><TD CLASS="quote">Thawley, I just threw a Skunk2 on my B18B, and the higher mid-range and top-end is WAY better. Unfortunately, that's all I can tell you. I haven't compared it to any others or anything, BUT what I understand is that the Skunk2 is like an ITR IM with an LS flange. If that's the case, I think it'd be a good bet, at least among OEM IMs.

In addition, the 403s are also very nice. The biggest concern with 404s is that you may not be able to rev as high as they're designed for. My 403s still feel strong up to 7200rpm. Given that you can't get past the LS rod bolt issue (unless you maybe use GSR/B16 rods or something?), there wouldn't be much point to using the 404s, as the powerband they're designed for wouldn't be yours.</TD></TR></TABLE>

ARP makes rod bolts for the LS and b20. You can also use better bearings and shotpeen the rods.

I Crower 404-2 and have no problems. I used to have idle problems, but those have been fixed. My powerband peaks at 7400 rpms. The only cams I have seen go to 8500 or higher are the Crower 405A and the Crane #20's. These cams are big cams and I wouldnt recommend them unless you had an extreme set up.

 

I know of the ARP rod bolts, but they're not legal for Honda Challenge. More importantly, your 404s peak at 7400? I'm really surprised by that. What's your build, and do you have any dynos?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dfoxengr &raquo;</TD></TR><TR><TD CLASS="quote">blox. same as skunk2 and cheaper. mill the head if youre allowed...</TD></TR></TABLE>
they are not the same...the runners are not the same sizes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sscguy &raquo;</TD></TR><TR><TD CLASS="quote">I know of the ARP rod bolts, but they're not legal for Honda Challenge. More importantly, your 404s peak at 7400? I'm really surprised by that. What's your build, and do you have any dynos?</TD></TR></TABLE>

Click on the links in my sig. They do not look like links but they are; just click on them.

Why are ARP rod bolts illegal for Honda Challenge?

If it is just dont disclose it. How many ppl do you honestly know in the Honda Challenge that have their motor built by the rules? There are many ppl that have forged pistons, cam gears, and aftermarket TB's. Hell I have even seen aftermarket AEBS IM's on 2 H1 cars.

So I wouldnt sweat ARP rod bolts!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sscguy &raquo;</TD></TR><TR><TD CLASS="quote">I know of the ARP rod bolts, but they're not legal for Honda Challenge.</TD></TR></TABLE>
9. Allowed Modifications- H1 Only
....9.3 Hybrid Vehicles Only
In addition to any unmodified part from any Honda or Acura model, market, or generation, the following components are unrestricted:
• Brake Systems
• Engine cylinder head porting (“from the block up”)
• Engine Management Systems
• Compression Ratio
• Fasteners (e.g. bolts) anywhere in the engine
• Valve preparation (angle, cut, etc) but not size or material
• Valve Springs, valve locks ,valve retainers, and valve shims
• Camshaft (except “K” series)
• Camshaft gears (including adjustable)
• Fuel Pumps, fuel Injectors, fuel rails
• Engine and transmission mounts, and associated components (shift linkages, etc) required to
perform an engine/drive train swap
• Engine management systems (ECUs, piggyback computers, etc)
• Any metal wheel (subject to 7.12(c) and 9.3.1(d))
• Battery type, size, voltage, and weight and location.

hybrid_vtec: Sorry I didn't get back to you over the weekend. I was at Buttonwillow for the last race. There's a photo thread here: https://honda-tech.com/zerothread?id=1398676
I'm scheduled for the dyno on Oct. 26th, but it's gonna be close. Not a lot of free time before then and SEMA and the final race of the season are the following week so there's no fall-back date. It's then or nothing for this season....

 

Whoa! Well, how about that. Last time I read the H1 rules I could've sworn it was illegal. Or maybe I'm just stuck in the H4/H5 rules, since that's where I'd be racing...

As for following the rules, I know at least most of the East coast guys have legal motors, and cheating is NOT just ignored. Maybe you West coast boys do things a little differently

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sscguy &raquo;</TD></TR><TR><TD CLASS="quote">Whoa! Well, how about that. Last time I read the H1 rules I could've sworn it was illegal. Or maybe I'm just stuck in the H4/H5 rules, since that's where I'd be racing...</TD></TR></TABLE>
Same here... I don't pay much attention to the H2-5 stuff.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thawley &raquo;</TD></TR><TR><TD CLASS="quote">
9. Allowed Modifications- H1 Only
....9.3 Hybrid Vehicles Only
In addition to any unmodified part from any Honda or Acura model, market, or generation, the following components are unrestricted:
• Brake Systems
• Engine cylinder head porting (“from the block up”)
• Engine Management Systems
• Compression Ratio
• Fasteners (e.g. bolts) anywhere in the engine
• Valve preparation (angle, cut, etc) but not size or material
• Valve Springs, valve locks ,valve retainers, and valve shims
• Camshaft (except “K” series)
• Camshaft gears (including adjustable)
• Fuel Pumps, fuel Injectors, fuel rails
• Engine and transmission mounts, and associated components (shift linkages, etc) required to
perform an engine/drive train swap
• Engine management systems (ECUs, piggyback computers, etc)
• Any metal wheel (subject to 7.12(c) and 9.3.1(d))
• Battery type, size, voltage, and weight and location.

hybrid_vtec: Sorry I didn't get back to you over the weekend. I was at Buttonwillow for the last race. There's a photo thread here: https://honda-tech.com/zerothread?id=1398676
I'm scheduled for the dyno on Oct. 26th, but it's gonna be close. Not a lot of free time before then and SEMA and the final race of the season are the following week so there's no fall-back date. It's then or nothing for this season....
</TD></TR></TABLE>

I thought they were allowed.

Oct 26th huh! I will let work know, and will call you this week to get all the facts straight!


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sscguy &raquo;</TD></TR><TR><TD CLASS="quote">Whoa! Well, how about that. Last time I read the H1 rules I could've sworn it was illegal. Or maybe I'm just stuck in the H4/H5 rules, since that's where I'd be racing...

As for following the rules, I know at least most of the East coast guys have legal motors, and cheating is NOT just ignored. Maybe you West coast boys do things a little differently </TD></TR></TABLE>

For the most part I think ppl follow the rules, b/c cheating isnt tolerated. However I have talked to guys that claim that they have forged pistons. Like I said I have seen a few ppl that have aftermarket TB's and AEBS IM's.

What I want to know is how some of the guys with the B20/Vtec's making 220+ whp on stock 84mm pistons? I mean most B20's come 8.8:1, and some are 9.6:1; however that still doesnt yield very high when you mated a Vtec head to the block. And the cams some of those guys run need compression!

Just a thought.

 

I don't know a whole hell of a lot about engine building, but I remember seeing some calculations of LS/VTEC setups having ~12.x:1 CR. That would be possible with CTR pistons, though I guess that doesn't answer the question of the B20/VTECs...