Engine Heeltoe Explains

Is a J37 manifold beneficial on a J32/35, or port the stock parts?

Many Honda and Acura V6 owners look to the grand-daddy of all J-series engine, the J37A4, for OEM upgrade mods. The primary item of focus is the large, Magnesium manifold topping that engine. However, there is some debate as to what the best course for intake manifold and throttle body use is ideal on a J-series engine. It’s well known that earlier J-series had removable plenums and internal trumpets that worked great and could more readily be ported out.

Heeltoe went out and got some information to help clarify things!

We’ll be updating this article as we learn more about the J37 intake manifolds and their applications.

Updated Dec 2, 2016:

This article was originally written to comment on the performance differences between a J37 Magnesium intake manifold versus porting out a factory J-Series manifold. Our expert adviser suggested that modifying the stock manifold was a more worthwhile effort when the cost is weighed out. But the market has decidedly chosen that modifying the stock manifold is too inconvenient when compared to simply buying a new part which works the same or better. Why?

Firstly, the stock manifold is not easily modified. Older J-series engines had removable plenums which allow them to be opened and ported with plenty of access. Anything 2004 and newer, though, is all one piece and is not really able to be opened up.

Secondly, who does the work if you want to send it out? Efforts in getting people to actually DO the work after they smugly comment “bah just get it ported” all seem to disappear when you ask for a reference or contact. Even people who say that “can” do it aren’t readily able to.

Thirdly, there is downtime to consider. If the customer doesn’t want downtime, they need to source a replacement manifold and the “it’s cheaper to port” argument gets thinner right off the bat.

Lastly, nothing in the parts world ever remains static. We’ve just recently revised and redone our manifold packages with new, lower-cost options for many J-series owners. Check out that listing here: HTSpec J37 Magnesium Intake Manifold & Throttle Body Kit, Honda J-Series V6 (ALL Single-Port Exhaust Engines)

HTSpec J37 Magnesium Intake Manifold & Throttle Body Kit, Honda J-Series V6 (ALL Single-Port Exhaust Engines)

Original post:

It is fairly commonly known that by upgrading the intake manifold on an engine, either by increasing volume or reducing restriction, more power can be produced within the engine. This is because air is more efficiently delivered.

As Honda engines have grown in size and power requirements, so have intake manifold volumes. As of this writing, the J37 intake manifold is an increasingly effective upgrade to do on mild and serious engine builds. But, are there real benefits over stock manifolds, or ported and polished ones?

We consulted Andy Gerzina, noted J-series engine guru, for his input. His statements to us, and we paraphrase, were:

Does the J37 manifold produce more power over stock intake manifolds which have been ported and polished?

  • Yes, to the tune of 2-3 HP over the rev range.

Do you generally recommend a J37 intake manifold to people building engines?

  • Since the cost of the manifold is over port work is relatively high (even more after considering a throttle body is added), and the gains are minimal, I find it more economical to upgrade the stock components.

It seems that if someone was starting from scratch and wanted maximum power a J37 package may be feasible.

  • It would depend on the person’s situation. On one hand, money would be saved obtaining used stock parts and modifying them, but it is also more time consuming and demanding of resources other than money. Simply ordering a J37 package may be easier for most users.

Are there any drawbacks to either porting or upgrading to the J37 intake manifold?

  • On Automatic transmission cars, no issues have been recorded or found to be troublesome with J37 manifold and/or J37 throttle bodies. On modern drive-by-wire j-series vehicles equipped with manual transmissions, there are well-documented rev-hang issues with the J37 throttle body, regardless of which manifold it is used in conjunction with. This change in drivability isn’t something one could not live with, but it may be favorable to port/polish the stock manifolds internals if you have a 6MT for seamless operation on the street. Currently, there is no consumer purchasable available adapter to convert a J32 or J35 drive-by-wire throttle body to a J37 manifold to solve this issue. With such an adapter in conjunction with a J37 manifold, performance gains are equivalent to porting a stock 2004-2008 TL/TL-S manifold.

Thanks, Andy, for the clarification!

Drivetrain Heeltoe Explains You Can Do It! DIYs

No Clutch Alignment Tool? No Problem!

NOTICE: This blog was written as I was installing a clutch and the alignment tool was mysteriously missing from the kit. I’ve gotten agitated calls about this relatively normal issue enough to have a lightbulb moment…this is not a huge deal, folks!

When installing a clutch it is necessary to align the disc with the flywheel before installing the cover (pressure plate). If you don’t, the input shaft from the transmission will not engage the disc properly and you will never get the transmission lined up and installed!

A clutch alignment tool is a specific tool with splines that match your transmission and a snout that fits in your flywheel. It holds the disc perfectly centered on the flywheel. Most clutch kits come with a clutch alignment tool matching your application.

But it happens rather often that you are not supplied the tool on accident, or you are doing a non-standard install, or are installing something used…no tool! Many customers get upset and concerned that they need the tool to complete the install. Getting the tool outside the kit is sometimes difficult and can take time…time you don’t have.

Instead of freaking out, grab a socket or tube of some sort which is a bit smaller size than the flywheel snout, and wrap some tape around it to fit into the flywheel and disc size. You might even have a different toll from a past job that is smaller and can be used. In my example, I am using a socket adapter that was rolling around in the toolbox. The splines are really less important…it is all about getting a snug fit.

Build the tape up a wrap or two at a time and test it a few times. Add tape as needed. You’ll find that you can get the disc pretty firmly in place by adding the right layers of tape.

There you have it! Installing a clutch with a clutch alignment tool is definitely preferred, and in some cases may be required. But for many installs, a little ingenuity is all you need to install your clutch without relying on tools you don’t need.

Drivetrain Heeltoe Explains

Acura TSX Clutch Kits for 2004-08 model years – What’s up with RSX-S parts?

The Acura TSX is a great car, and one of the best things about it is the availability of a 6-speed manual transmission. It’s a sophisticated gearbox featuring a light-weight Magnesium alloy case for lightweight construction. That makes the 6-Speed TSX unique, even among other Honda and Acura cars.

Interestingly, the stock clutch is also different than most other Honda/Acura transmissions in that is it produced by AP in Europe, a company renowned for their work in brake friction. It’s much more common to find Hondacars with clutches made by Daiken corporation.

This break in normal supply has transcended into the aftermarket as well. It is actually quite hard to get low-cost cores from which performance aftermarket clutches can be made (yeah, most performance clutches are rebuilt from completely stock cores!) The clutch is so different from other K-series clutches that it uses a completely different flywheel. The clutch from a 1g TSX is considerably larger, offering more leverage within the cover to hold the increased torque in the K24A2.

Question: Without any aftermarket options, what do you do if you’ve boosted your TSX with a CT Engineering supercharger or done other upgrades to the engine and more clutch holding-power is needed?

Answer: Buy RSX-S parts!

Yes the TSX engine and transmission, while joined with a unique clutch, are still very similar in design with conventional design as other popular K-series applications. Simply swapping the TSX flywheel for an RSX-S flywheel allows the use of a very wide array of clutches, as the RSX-S is one of the most commonly modified Acura models using a K-series engine.

This should explain the odd listings you will find showing no TSX clutch available, or a caveat that the flywheel must be changed to use it. So if you want an aftermarket clutch, know that ANY application from an RSX-S will work in a TSX as long as an RSX-S flywheel is installed.

Bonus Post-Script!

Did you know that Heeltoe commissioned the production of a 2004-08 TSX specific performance clutch and flywheel? Sourced from vendors AASCO Motorsports and Clutch Net, we had made a TSX billet aluminum flywheel and rebuild a used core TSX clutch cover (pressure plate). The disc is a rigid hub full-face design, providing fast acceleration and direct power transmission from the crank to the wheels. As of this writing, the clutch and flywheel combination is being used in the HTSpecTSX. The images of that combination were used for this entry.