new to hondaswap turbo setup question....

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New Member
so hello to every one reading this i have a question now i dont own a honda but im trying to figure out how they make power the way they do

now all the info ive obtained is from forums and friends with hondas ...but the thing is im a nissan guy now most people run very low boost with around 9.x:1 comp ration and make lower hp then hondas. now hondas (from what ive heard) run upwards towards 10:1 or 11:1 (if not higher) with higher boost

can you guys give me some info on your turbo setups i dont want all your well kept secrets just some info

1engine (b16 b18 gsr ect.)
2 compression ratio
3 boost amount in lbs
4 amount of whp and tourqe
5 if you run egr or not
6 and what your average AFR is
7 and if you feel like it if you have a more agressive cam (with more valve overlap)

i would like to thank any1 who shares this info in advance and please if ive made any mistakes in were to post this question im sorry and if im wrong all together about the comp ratio and boost thing please tell me right away



Unlike nissans that are done at 6500, honda's are just getting started at this point making their peak power. So, sizing is a bit different. t25's fall flat on their face up high in the revs because they can't keep up. With the extra rpm the honda's can provide, a larger turbo can be used.

Most people build around 9-10:1, with the later being for milder set ups, and the former being for more agressive/sleeved blocks/etc etc set ups with big boost. Compression keeps torque and off-boost response and even increases spool time. 11:1 is not unheard of, as there are many boosted ITR boost set ups. But, there's far less room for error and tuning gets harder, and you end up hitting a threshold of where you'd be bette roff with lower comp and more boost.
see also:

there's plenty of tuning tools that are great, and any 11.8-12:1 target afr is easily obtained with proper tuning and some dyno time.
Most folks run stock cams. Some move up to ITR cams, or a turbo grind that is generally more higher lift with similar duration. aka, not much more overlap than stock. But a lot of folks have made good numbers with CTR cams which are the largest oem cam set up.


New Member
so because they rev higher they maintain lower CC temps so u can raise boost? what im not getting is when i tuned a b16 (gsr cams) all we did was dial back fuel and retard timing but with boost i think u advance timing and add fuel then lean it out from there and monitor AFR ratio and exhaust temps but if you can run lets say a 12:1 with 8lbs you would dial back boost and fuel so you have room for temp/humidity change

but whats the stock redline on a honda engine (average maybe) i mean if you build it for HC + boost your probably gonna rev higher and if you swap cams you can advance cam timing and get cool air in sooner and hot hair out sooner so you keep your engine cooler

that sound right to u ?


boost is a relative number... it's about CFM of air moving in based on size of turbo, a/r, rpm, etc etc etc.

Generally, you pull about 1 deg of timing per psi per 1k rpm as a baseline, and run it rich so it doesn't pop on the first pull, and then lean it out from there.

most b-series redline stock at 8k rpm. its common to go to 8200 or so without doing any head work. adding bigger cams/springs/retainers, they can do 9k all day. high built motors can hit 10,500. but, thats more common in all motor set ups. Again, the turbo runs out of breath and falls out of its efficenecy range on those engine speeds.


New Member
i agree with B... realize that not every honda engine is the same, theyre all very different. a stock gsr engine may do 8000-8200 rpm redline, but a typre R engine (theyre both b18's) will do 9000-9500rpm from the factory. all these engines have different compression ratios

my engine:
b18c5 (us type R engine)
10.6:1 CR
6psi on A/R 50
8500rpm rev limit
11.5-12.2 ish Air/fuel (full throttle)
mustang dyno
315whp/200ft tq.

stock naturally aspirated it made 175hp

**and with fuel injection and especially turbos, you want a cam with less overlap. if your exhaust valve is open when the intake opens its just going to push your valuable boost into the exhaust lol