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I BOUGHT A 1991 CIVIC HATCHBACK RACE CAR THAT RUNS SCCA IMPROVED TOURING B. RULES SAY I NEED TO STAY WITH THROTTLE BODY INJECTION. Hard to find any upgrades to this motor besides air intake pipe & headers. I put in an air/fuel meter, shows it's running lean but there is no adjustment on the fuel regulator. Has anyone fitted an adjustable regulator to one of these? B&M says their's doesn't fit. Is there only one cam that would be stock legal for this motor?
I've been told to put in an aftermarket ECU & wiring (AEM or Haltech), but would that help with a stock motor? Can anyone recommend someone who knows how to get a little more out of the D15A2 motor?
 

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Do the SCCA rules allow intake manifold changes if you keep the same injectors and throttlebody setup? Also send a pic of the fuel pressure regulator, I bet I could come up with something adjustable if the rules allow it.
 

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Brokedick Millionaire
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Do the SCCA rules allow intake manifold changes if you keep the same injectors and throttlebody setup? Also send a pic of the fuel pressure regulator, I bet I could come up with something adjustable if the rules allow it.
no, no, no.

IT engine rules are simple....

.043" overbore, stock style piston in weight, construction, and material
.5 bump in compression
1" limit on "gasket matching/porting" on either side of the intake to cylinder head gasket surfaces.

Stupid simple cheap rules.
 

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What about the fuel pressure regulator? Is an adjustable one allowed?
 

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Brokedick Millionaire
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It is all covered in proper forums.....maybe even on HondaTech before the split a few years ago, as well on here.

OK, maybe it was 10 years ago.
 

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So I was reading the SCCA 2012 rulebook, which seems the most recent, and it allows the use of any jet changes on carburated cars and it allows any ECU or fuel pump changes. Since they are clearly allowing fuel tuning, so I assume that adjustable fuel pressure regulator is PROBABLY acceptable.

When it says "Updating and/or backdating of components is only allowed within cars of the same make, model, and body type (eg. Sedan, station wagon, convertible, etc.) and engine size as listed on a single Improved Touring specification line. Any updated/backdated components shall be substituted as a complete assembly, (engine long block, transmission transmission transaxle, induction system, differential/axle housing)" does this mean that you could take the entire induction system off CRX HF and put it on a CRX Dx? Also it doesnt state anything about years, just make and model, so could you put a carburated system off an earlier 1.5L CRX onto a CRX DX?
 

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Brokedick Millionaire
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What sub-section were you reading, you're not reading deep enough.

GCR rulebook comes out yearly.

Which "line" is the car classified in?

Really spend some time, it will take a week or so.

FYI: some of my specs that are listed on here were requested by SCCA years ago. Dunno if the issue was ever cleared up, or protested.
 

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Its called 2012-GCR.pdf and I found it on the SCCA website while looking for the IT rules. I will get out my damn laptop and look, I cant copy and past shit on my phone....

EDIT From the 2015_GCR-November from the SCCA site, page 511:

9.1.3. IMPROVED TOURING CATEGORY
These specifications are part of the SCCA GCR and all automobiles shall conform with GCR Section 9.

A. PURPOSE Improved Touring classes are intended to provide the membership with the opportunity to compete in low cost cars with limited modifications, suitable for racing competition. To that end, cars will be models, as offered for sale in the United States. They will be prepared to manufacturer’s specifications except for modifications permitted by these rules. Cars from the previous four (4) model years and the current model year will not be eligible. No car older than a 1968 model of any listed vehicle will be accepted for Improved Touring competition. Turbocharged/Supercharged cars are not eligible for Improved Touring competition. Cars need not be eligible for state license or registration.

B. INTENT It is the intent of these rules to restrict modifications to those useful and necessary to construct a safe race car. This class is intended to allow a variety of popular, inexpensive cars to be eligible; however, those determined by the Club to be outside of these parameters will not be classified. Entrants shall not be guaranteed the competitiveness of any car, and competition adjustments, other than as outlined in section 9.1.3.C, are not allowed. Other than those specifically allowed by these rules, no component or part normally found on a stock example of a given vehicle may be disabled, altered, or removed. Note: This new statement of purpose and intent eliminates the dual purpose version which does not accurately reflect the current IT technology. In addition, it emphasizes the philosophy that we will give you a place to race your car and have fun, but not guarantee that you will be competitive.

C. SPECIFICATIONS The SCCA shall publish the Improved Touring Category Specifications (ITCS) containing the officially recognized specifications for each car eligible to compete in the Improved Touring Category during the calendar year. To maintain the stock basis of Improved Touring, updating and/or backdating of components is only permitted within cars of the same make, model, body type (e.g., sedan, station wagon, convertible, etc.), and engine size as listed on a single Improved Touring Specification Line. Any updated/backdated components shall be substituted as a complete assembly (engine long block, transmission/transaxle, induction system, differential/axle housing). No interchange of parts between assemblies is permitted, and all parts of an assembly shall be as originally produced for that assembly (such parts may, however, be coated, painted or plated). Additionally, it is not permitted to “create” a model or type of car by updating or backdating assemblies. Parts or assemblies which the manufacturer lists in factory service manuals or parts guides for a particular model which supersede or replace original parts or assemblies are permitted. Documentation of the superseding parts or assemblies must be supplied to the Club Racing Department and the appropriate part numbers listed on that particular model’s specification line.


Honda CRX HF 1.5L (88-91)
4 Cyl SOHC
75.0 x 84.5 1493
(I) 29.0 (E) 25.0
9.690.6153.25, 1.65, 1.03, 0.92, 0.69
(F) 231 x 17 Solid Disc (R) 180 x 39 Drum
2030

Honda CRX 1.5L (standard) (88-91)
4 Cyl SOHC
75.0 x 84.5 1493
(I) 29.0 (E) 25.0
9.290.6153.25, 1.89, 1.26, 0.94, 0.77
(F) 242 x 21 Vented Disc (R) 181 x 39 Drum
2110

Honda CRX 1.5 (84-87)
4 Cyl SOHC
74.0 x 86.5 1488
(I) 27.1 (E) 32.1
9.686.6152.92, 1.76, 1.18, 0.85, 0.71
(F) 231 Disc (R) 180 Drum
1955Plastic front fenders, nose, lower body segments. CVCC Cylinder head.


Unless I am reading this wrong it looks like you are allowed to switch "Complete Assemblies" between 88-91 CRX DX and HF like an "induction system". However the 84=87 CRX has a slightly different displacement engine, so you are probably not allowed to swap in that stuff, although it is very similar in size and slightly smaller so maybe. Also it says listed options, did Honda ever list a 1.5L 88-91 USDM CRX with a carburetor? Even if they didn't actually make one in the US, if it was "Parts or assemblies which the manufacturer lists in factory service manuals" it looks like it might be allowable if you can find a stock carbed induction system from a CDM/EDM/JDM model.

Not sure how much the HF intake would help on a DX, but it might be worth looking into.
 

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"Complete Assembly" means the entire engine/driveline as a whole unit. You cannot pair an Si tranny with a DX motor and be ITB "legal" although the only difference is case bearing size and offers no performance advantage.

It basically allows you to use any chassis, like putting an Si driveline into an HF tub. Before you had to use an Si tub to run an Si driveline.

complete assembly = (engine long block, transmission/transaxle, induction system, differential/axle housing) one whole unit.

89 CRX HF tub, rust free....see why I'm keeping it?

84-87 CRX driveline is for a different generation, not allow to update/backdate across generations.
 

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"Complete Assembly" means the entire engine/driveline as a whole unit. You cannot pair an Si tranny with a DX motor and be ITB "legal" although the only difference is case bearing size and offers no performance advantage.

It basically allows you to use any chassis, like putting an Si driveline into an HF tub. Before you had to use an Si tub to run an Si driveline.

complete assembly = (engine long block, transmission/transaxle, induction system, differential/axle housing) one whole unit.

89 CRX HF tub, rust free....see why I'm keeping it?

84-87 CRX driveline is for a different generation, not allow to update/backdate across generations.
Are you 100% sure? The way it is worded makes it sound like you are allowed to change just the transmission assembly between a CRX Hf and DX.

What you said about bodies vs drivetrains doesnt make sense either, because according to "updating and/or backdating of components is only permitted within cars of the same make, model, body type (e.g., sedan, station wagon, convertible, etc.), and engine size " you shouldnt be able to swap ANYTHING between an HF/DX and an Si, because the Si has a different engine size.

Is it just worded poorly? Do you have specific confirmation from a higher up rulemaker that isnt covered in the rulebook?
 

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By the way, the Above FSM does list the 1.5L (1493cc) engine with the dual carb option. Doesnt that mean that you could swap in either that intake and carb, or the whole drivetrain assembly, and run it in the ITB class?

According to wikipedia:
1988 Honda CRX 1.5X (rare)
1990 Honda Civic 25XXT Formula (Japanese Market)
Honda Civic Ferio MX (Japanese Market) EG8
1998–2001 Honda Capa GA4 (Japanese Market)
1988-2001 Honda Civic SH4 EF1
Displacement : 1,493 cc (91.1 cu in)
Bore and Stroke : 75 mm × 84.5 mm (2.95 in × 3.33 in)
Compression : 9.2:1
Power : 103 hp (77.23 kW, 105 PS) at 6,800 rpm
Torque : 14.1 kgm (133.4 Nm) at 5,200 rpm
Rev limiter : 7,200 rpm
Valvetrain : SOHC (4 valves per cylinder)
Fuel Control : Twin carburetor PGM-CARB/fuel injected

If so that 11 more HP and tunability over the 92hp d15b2 DX is kinda nice, plus it looks like you are allowed the ability to swap in a few other carbs, which may or may not further increase your power.
 

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When you read the GCR, all restrictions apply from previous sections unless otherwise specifically allowed in later paragraphs or spec line for a car. If there are no spec line allowances for a particular car then you cannot swap bits and pieces as Bone has stated - they would show up on that particular car's spec line, if allowed.

There are some allowances for all carbed cars that are covered in 9.1.3.D.1.5.

EDIT - here's the 2015 GCR, straight form the SCCA website...http://cdn.growassets.net/user_files/scca/downloads/000/007/704/2015_GCR_May.pdf?1434659314
 

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Was it available in the US market????

No.
Was it? I dont know. Its listed in the FSM as an option, wikipedia lists it as rare, and I have certainly not popped the hood of every USDM CRX ever made. For all I know honda made 5 of them for the US and they were all wrecked in 88.

If there are no spec line allowances for a particular car then you cannot swap bits and pieces as Bone has stated - they would show up on that particular car's spec line, if allowed.
What do you mean by that? What is a spec allowance, can you give an example? Because I dont see anything on the lines of cars under the ITB section.

Also the GCR I quoted was the November 2015 version, what you linked was the May 2015 version.
 

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FSM also has camshaft specs listed wrong in some issues.
Parts or assemblies which the manufacturer lists in factory service manuals or parts guides for a particular model which supersede or replace original parts or assemblies are permitted.

That makes it sound like if it is listed in the FSM manual it is legal. Is there something that stops you from ordering up a d15b dual carb swap online and dropping it into an 88-89 CRX and competing in ITB?
 

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Sorry Joel - I didn't see that you had updated from your reference to the 2012 GCR.

Look at page 559 (it is on the left hand edge of the PDF) - there's the spec line.
 

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I see the line with the specs, I posted them in the post with the long quote, but I dont know what you mean by "spec line allowances" can you give an example of a car that does have them? Or what they are/mean?
 

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Parts or assemblies which the manufacturer lists in factory service manuals or parts guides for a particular model which supersede or replace original parts or assemblies are permitted.

That makes it sound like if it is listed in the FSM manual it is legal. Is there something that stops you from ordering up a d15b dual carb swap online and dropping it into an 88-89 CRX and competing in ITB?
because it was never offered in the USA.
 
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