B20Vtec, which head, which cams? Ecu Q?

AutoB20V

New Member
Whats up CI? I am new here and have some questions. I drive a 1995 Acura Integra Ls that I have had for a little while, but do not know all that much about Hondas, but have a friend that is pretty smart with Hondas. I asked him if there was a bigger engine I can put in my Integra that offers more displacement, in turn offering more torque. He said that the CRV had a 2.0L b20, which has the same stroke as my 1.8L b18b, just a larger bore and should deliver more tq than my stock b18b. Is this 100% correct? He also later suggested adding a vtec head to the b20 block, so I started reading up on "ls/vtec" like he suggested, and feel like I have learned a good amount on the ls/vtec build. Now my questions.

I know I need a b series dohc vtec head from engine like a b16 vtec, b17 vtec or b18 vtec, but I want your help as to which head best suits my needs. I obviously want torque which is what brought up the b20, but would like a little more hp as well, but mainly torque, and do not, repeat do not want to rev past 7k rpm, so which head would be best for a 7,000 rpm redline? Also, I have read that the b16 vtec, b18 vtec gsr and b18 vtec itr heads have different cams. Which cams would best suit the 7,000 rpm redline?

I also have been reading about chipping the ecu to tune for the different block and different head, but still had some questions. I read that anyone competent with chipping obd1 ecus can easily add vtec while chipping it, but have not read anything about adding iab from a gsr. Is it possible to add both vtec and iab to an obd1 p74/p75 Ls ecu? I am asking because I think the dual runner Iab intake, and the 4,500 rpm vtec from the gsr would best suit my want for torque and the 7,000 rpm redline, but I am not too sure as I have just started research, which is why I am asking you guys.

Which head for 7,000 rpm redline b20vtec? (b16, gsr?)
Which cams for 7k rpm redline b20v? (b16,gsr?)
Can I add vtec and Iab to Ls ecu, or just vtec? (incase the gsr head, cams and intake are best for this scenario)
 

Integraguy04

CORNER CARVER
Ok with me being a b20/vtec master (lol not really - just have had one for a long time) I will give you my opinion.

Head: GS-R - its increases compression so has ability to make more power with a stock b20 bottom end.
Cams: I would just get atleast GSR ones - if not type R cams if you want to stay OEM - there are far better ones out there.

In order to have it run properly you should really get an engine management system and have it tuned (Any B series VTEC ecu will work). LS/B20 - VTEC motors have way different A/F maps than others - a stock GSR map (example) wont really work on a build like this. Get a tune!

If you use the stock harness - you will have to wire up vtec independently.

Here is the other thing - you need to rev that motor till atleast 7500 - 8K is where you will see the max power - and there isnt any real way to make it rev lower - if you build it right and treat the motor right it wont fail...i rev mine to almost 9K on a stock block and its been fine for 3+ years.
 

2kdb7

Member
Number one rule for this build is don't be cheap. You don't have to throw thousands at it but get quality parts. There are a few write up that are really helpful just dig around on the site homework is a must before you start
 

Muckman

Not a M0derator
There is no VTEC cam on the market that is designed for a 7k redline.
I guess stick with a stock GSR cams if that is your goal.

If you want IABs then youll need a P72 which has the output for IABs.

I have a LS crank in a GSR block. Rev to 9200. Its only 1.8mm longer stroke than GSR/ITR.
 


NemesisCBR

Boredest Member
Build it right first of all. The redline will be at whatever is optimal for it. You cant exactly choose that and build around a set redline but its simple... just shift at 7 if thats all you want. If you intend to stick with this scenario then id recommend building everything with low/mid in mind. I'd definitely stick with a gsr intake manifold for this.
 

BigMac88

Fat guy in a little 'teg
Integraguy04 said:
Ok with me being a b20/vtec master (lol not really - just have had one for a long time) I will give you my opinion.

Head: GS-R - its increases compression so has ability to make more power with a stock b20 bottom end.
Cams: I would just get atleast GSR ones - if not type R cams if you want to stay OEM - there are far better ones out there.

In order to have it run properly you should really get an engine management system and have it tuned (Any B series VTEC ecu will work). LS/B20 - VTEC motors have way different A/F maps than others - a stock GSR map (example) wont really work on a build like this. Get a tune!

If you use the stock harness - you will have to wire up vtec independently.

Here is the other thing - you need to rev that motor till atleast 7500 - 8K is where you will see the max power - and there isnt any real way to make it rev lower - if you build it right and treat the motor right it wont fail...i rev mine to almost 9K on a stock block and its been fine for 3+ years.
Click to expand...
^This.

OP, also the GSR head is also more advantageous in the sense that it has quench pads which aid in detonation resistance. It also flows ever so slightly better in the mid range than any B16 head and comparable or better up top with some proper porting.

If you run the GSR head (even a B16 head), you won't be able to run larger than a factory ITR cam without having piston-to-valve clearance issues - especially on the B20Z (high comp). The valve reliefs in the pistons aren't quite large enough for the valves on VTEC heads.

A cheap way to ensure your B20/VTEC will give you at least a little bit of life it to use ARP rod bolts. The factory rod bolts are the weakest part of the B18B/B20 IMO. The rod/stroke ratio is slightly worse than a GSR , but very minimally. B20 r/s = 1.54, gsr = 1.58 and a GSR bottom end can easily rev to 9k+.
 
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AutoB20V

New Member
I might, might set the rev limit up to 7500 rpm, and never rev past 7500, as I am not really concerned about high rpm power, my main goal is low rpm torque (hence the b20), but would still like a little more top end than a stock b20 non vtec for passing on the freeway etc (hence the b20vtec). I really don't see the need, and really dont want to rev past 7500 rpm tops, and figured ctr and itr cams would be pointless for a "torque build" and a relatively low 7500 rpm rev limit. So far the plan is b20z block with new oem bearings, new oem rings, and and rod bolts. Stock crank, rods, pistons. As for the head I guess I will go with a b18c1 head as advised, but was just curious about the "best" cams for this setup. Would any oem cams be better for this setup (b20z, gsr head/im, 7500 rpm rev limit, looking for torque) than stock gsr cams? I know ctr/itr cams wouldnt work well, but are there any b16 or b17 non type r cams that would be better than stock gsr?

Also, is it possible to add IAB to an obd1 Ls ecu (p74 or p75 I think), or just the ability to add vtec?
 


darksands

New Member
Here is my build.
Stock B20B low comp
Stock Intake/TB
GSR Head With Supertech Valve Springs
CTR Cams
GSR Intake Manifold
P72ECU with Hondata S300.
96Spec ITR Header 2.5" Collector
Apexi WS2 Catback
I limit my revs to 7800 but they were running it to 8300 on the Dyno just fine.
Putting down 175HP/137TQ on a Dynapack
Dyno Chart

AutoB20V said:
Also, is it possible to add IAB to an obd1 Ls ecu (p74 or p75 I think), or just the ability to add vtec?
Click to expand...
If you get Hondata S300, you should be able to control IAB but I am not 100% sure.
 
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Integraguy04

CORNER CARVER
AutoB20V said:
I know ctr/itr cams wouldnt work well, but are there any b16 or b17 non type r cams that would be better than stock gsr?
Click to expand...
Your missing it - CTR and ITR cams be much better than gsr or b16 cams - even though you only want to rev to 7500 - any cam with more lift/duration will provide more power and more torque - cams aren't always designed on top end, they do factor torque as well.

Example - when I changed my cams from stock gsr cams to skunk2 pro 1 cams and had it tuned - I gained over 10 ft lbs



Sent from my iPhone 4S
 

AutoB20V

New Member
Also, is it possible to add IAB to an obd1 Ls ecu (p74 or p75 I think), or just the ability to add vtec?
 
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