Hey HT, currently building a daily driver GSR with ac/ps and I would like to hear feedbacks/experiences on a high compression turbo build. Car will be on E85 with a GREAT tuner.
Here is my build list:
stock gsr transmission
stock b18c1 block bored .20 over (81.5mm)
stock b18c1 head with supertech dual valve springs and titanium retainers
ARP headstuds, rod bolts and flywheel bolts
oem bearings, seals, oil pump and water pump
ls crank
manley h beam forged rods (ls rods)
wiseco +8.30CC forged pistons
skunk 2 pro intake manifold
injector dynamics 1000cc injectors
AEM fuel rail
hybrid racing 355 lph fuel pump
Rev9 turbo kit
PLM ramhorn SS manifold
3 in exhaust
ACT 12lb flywheel
ACT XTSS
Hondata S300
EVERYTHING has been checked and machined by Arlington Machine, CA
Compression ratio will be in between 12-12.5:1 depending on the headgasket
Looking to get around 350-400whp/280-320wtq with this setup

 

If the engine is already built, roll with it. If not, id get slightly lower pistons. May want to invest in bigger volume injectors. Also due to the compression number, sleeves would be a good ideal. I realized the ethanol acts as a cooling agent. But theres still great chance of detonation. Next, it doesnt really making sense to have that much compression on stock cams. Assuming because you have it listed as stock head. Finally, i would be finding a tuner, who has experience tuning high compression, high whp hondas. That is the most important thing

 

If you don't already have the S300 I'd consider something like a Link HC92X, or a Haltech 1500 - The S300 isn't a bad platform IF (and these days it's a big if) you have a healthy OEM OBD1 ECU to work off of, but even in that case the old ECU is still limited by polling rate and processing power versus these newer standalones. A build like yours needs a good tune to work properly, and obviously having a very capable ECU and software behind that tune would help immensely.

If you already have the S300 and know the board is in good shape then don't worry about it, otherwise I'd go with one of the other two mentioned. I also agree with Joker on sleeves if you have cash to spare, and maybe something like Tuner 1 cams. The problem you'll run into however is your pistons are going to want big cams, but the turbo you're going to be running for your target power levels is going to be fairly small and will be choked out if you go too big on the cam - Tuner 1's are probably the largest I'd go, your OEM GSR cams will otherwise be ok. Expect your power to start dropping off by 8200, maybe 8500 at latest, that intake manifold will also be out of breath by then.

Or, after all that rambling and what I just pointed out - I again agree with Joker on lowering the compression to something like 11:1 as you're not in a position to take the most benefit from the ultra high 12-12.5:1.

 

Following

 

If i had the option i would do 11-11.5:1 but money is tight and i picked up a brand new set of wisecos for only $200. I would also love to sleeve but i just cant afford it right now. The reason i am running stock cams is because ill be boosted and tuner said stock gsr cams are capable to reach the power goals. From what i understand you choose your cam based on your displacement not compression ratio and in my case something like tuner 1 would work for my build but not necessary to reach 350whp. I do know im not making the most out of 12:1 comp but i am not trying to get the most power out of it right now, just something that has a quick turbo response, preppy and still daily-able. As for the injectors what size would you guys recommend? I used the FIC calculator and for 80% duty cycle @350whp i would only need a 920cc injector so i chose a 1000cc to have a little bit of wiggle room. As far as the ecu i chose the s300 since its more budget friendly than standalones but I can probably increase the budget for a link hc92x since my tune is the most important part. Im not sure if you guys have heard of KVtuned from socal but he does a lot high comp builds with crazy numbers doing pass after pass on the strip. Confident my tune will be spot on with him.

 

GSR cams are definitely capable of hitting your power target. Incorrect on cam choice - Displacement could be a factor, but compression ratio matters arguably more - Then more variables like how your intake and exhaust manifolds flow, how much CFM your head flows, etc. Displacement is relatively inconsequential to some of those other aspects. Side note though that larger bore sizes with matching chambers on the heads typically flow more especially at higher RPM.

1000cc injectors are fine as long as you don't go over your mentioned target of the low 400WHP with E85. General advice is don't go over 90% on injector duty cycle.

Get the HC92X. Do you already have the turbo kit? Does your car have AC? With your engine combination and power goals you may want to even consider a supercharger kit instead. @wunfastgsr Have you already sold your Procharger?

 

Ah gotcha, a different tuner explained to me that displacement was more important than the other factors. Not only do i have stock sleeves but theyre also bored out which forces me to stay 350-400whp at most so ill probably get 1000cc injectors. If i had the money yes i would supercharge but sadly they cost a lot more than an ebay turbo kit. I do have AC and PS but the manifold im getting allows me to keep both.