Helping a friend tune up his 98 Type R and the distributor Honda Part# 30102-P72-006 shows to be cross compatible with both GSR and Type R B18C engines.

However upon install we noticed everything lines up except the screw hole nearest to the firewall is about 3mm off and the supplied bolts are actually longer than the original ones on the current distributor.

We double checked parts suppliers and they all show across the board distributor caps #30102-P72-006 are suppose to be compatible with both GSR and also the Type R B18 engines.

After searching on the forum, I've seen conflicting reports to posts dating 20 or more years back with many people saying GSR and ITR is the same, but a minority of users also reported GSR distributor cap not being able to fit because of a 2-3mm difference where the bolts lines up.

I also read Type R distributors are different than GSR because of the limited degrees you can adjust timing compared to GSR because of the higher compression of Type R engines the engineers wanted to prevent people from over advanced timing.

So if we want to replace the distributor cap to a fresh one or even a new distributor is there exactly a Type R dizzy cap or distributor unit? or would we have to change everything over to GSR going forward?

Hope this thread clears up alot of info I'm sure other ITR owners have experienced. Almost 30 years since this car was created and we still have questions.

Thanks in advance.

TIA

 

IF you are referring to Genuine OEM Acura distributors... then yes, the GSR and ITR distributors are dimensionally the same. The distributor caps are identical. The challenge that you run into with respect to cap fitment comes from the aftermarket. Since the distributor housings for the GSR and ITR will also work functionally correctly on a B16A3 and a B16A2, almost all aftermarket manufacturers will only produce ONE version, and since the OEM Honda B16A distributor utilizes the same distributor cap found on the SOHC D16Z6 engine, it is quite logical that they would produce the distributor housing size that utilizes the smaller diameter cap.

The inconsistencies that you have discovered in your research will in fact be the result of comparing OEM distributor housings and aftermarket housings.

 

You can confirm by checking part #s on the parts website, but the 98+ all run the P73 (TD-87U) and the 96-97 GSRs ran a P72 (TD-84U). I had both side by side and could not see any differences in the castings. So the question is what's the casting number on your friends. Believe the B16A3s in the 99-00s SIs were TD-81U. Believe the OBD1 GSR were TD-68Us and the early B16 Del Sols were TD-44U - but those should be OBD1 distributors (with the 96-97 Del Sol OBD2a receiving the TD-81U).

Don't be surprised if your friends ITR does not have the correct / oem distributor - they went bad, were swapped to OBD 1, etc quite often; even early in ownership. The code should help resolve which cap you need though.