hondasingapore

hi, FI buddies:

Plan to change my GT2871R as my tuner told me it was out of breath after 7000RPM, how true is it as I am using a 0.82 Turbine A/R with 8200RPM as Rev Cut? I am disappointed with the power and torque as I am expecting more. Previously I was using HKS GT-RS, I think it produced more power/torque, but it was done on a dynapack dynamometer. This time the dyno is called Hyper Power Dyno at www.hyperdyno.com

I turn to you guys are you guys have the most powerful FI setup on Honda, not those Japanese or us ...

Setup
=====

1999 Honda Civic 4-Door-B16A1 or JDM SiR or your Civic Si's equivalent
ERL Superdeck I B18C1 Darton-Sleeved Block
Stock B18C1 Head with GSR Cam
Power now is 350 HP at 1.4 bar of boost
HKS Cast Iron T25/T28 Turbo Manifold
TIAL 44mm External Wastegate
Edelbrock Performer X Intake Manifold
HKS F-CON V-PRO ECU
Koyo Full-Length/Width Radiator
QUAIFE L.S.D.

Goal
===
450-500 HP (must retain existing Koyo Full-Core Radiator)

Questions
========

1. Some sources were saying I need to swap to a T3/T4 flanged Turbo as the existing GT25/GT28 can't flow so much ...

2. Some sources told me to junk that HKS Cast Iron manifold to go for ramhorn together with a NEW turbo charger like GT3076R or GT35R ...

Any suggestions esp. proven ones are welcomed as I thought GT2871R will cut it into at least 450 HP range, etc.

Thank a lot, pals ...

Hondasingapore

HiProfile

Search google for Evan's tuning dyno library, they have some stuff you'll want to read abotu all 3 turbos. Most people in the states can get over 400 whp from a GT2871R, but 450-500 is really pushing it. A bigger GT30 wouldn't have a problem reaching that goal, and a GT35 will want to go much further.

The current problem may be your manifold & downpipe. Although people have done 500+ whp with cast manifolds, that's usually with a large tubular downpipe, 3 inches or larger. Your cast downpipe elbow is restricting quite a bit of power, so will almost any cat.converter you're running, and any muffler that isn't straight-through. Get a full 3" exhaust and better downpipe elbow and you may pick up a free 50-100whp just from that.

BTW what kind of Air Conditioning setup is that? Are you using something like an Accord unit in front of your radiator??

hondasingapore

HiProfile:

The power of 350 HP is on this Hyper Dyno, anyone here has experience on such dynanometer as it tends to generate lower figures for power/torque as told.

Thank for pitching in! Yeah, my downpipe is already 3" throughout and my mid-pipe is Thermal Research with rear muffler of DC5 or new DC2 but had been operated or made straight through (I HAVE NO CAT at all). The one that you saw in my attachment was the wastegate dump pipe if you are referring to that one.

I am running normal stock 1999 Honda Civic SiR/EK4/B16A air-conditioner.

Others, please come in and I can post more pictures if needed as I do not want to miss the boat again this time.

Plan
===

Get a set of new 84mm piston as they have been old (since 2007)
Send my B18C1 head to endyn for port/polish & valve job
Get a FInduction cam
Use back stock-sized Supertech 33mm Intake & 28mm Exhaust Valves. Now, it is 34mm and 28.5mm
Get a new turbine, most probably GT3076R with 0.82 A/R (Turbine). Like others said I do not mind a bit of lag to compensate for LESS wheel spin during launch, etc.
Re-tune

Thank a lot, all!!!

Horseofcourse

Maybe some cam's?

TheShodan

iTrader: (14)

He may not need the cams yet. That's the last part of a setup that he may need to get the power he's looking for. bottom line is that for the power he's looking for, he's out of efficiency with the GT2871R.

The OP is at a point where he needs to change a lot of his setup to fit more for a top end power monster, considering that he's looking for such high power to the wheels. A 58mm + inducer compressor wheel would be more in order, but hopefully at this point he understands that "spool" is going to be something that is to be sacrificed when going to these power levels. Considering he already has the fittings, water lines, and return flange, he's already setup to GT35R standards for this power level, as well as the use of a different type of manifold to accommodate the increase in exhaust VOLUME needed to power this turbo.

A note of caution:
Using 84mm pistons even on a GS-R is not going to increase your torque much, because you haven't addressed the issue of FULL change in displacement (bore AND stroke). You may only see a relative increase in torque of about 20ft/lbs compared to 81mm. (You do understand that the engine will need to be sleeved to accept these pistons)

This is not an NA car, so Port N polish is not necessary. You're forcing air into combustion, not scavaging for it like an NA car. I have found that because the B-series and K-series are already over engineered for boost, there was only a 30cfm comparison between a PnP'd head and a stock one FOR BOOST.. NA is a different story

"Less wheel spin during launch" may be your motive to going for such a larger turbocharger, but don't forget the after effect of going that route. 1) Lower duration of maximum torqueband (only about 1500rpms of usable torque), and 2) the "light switch effect" that tends to occur with our cars.

Once the turbo matches its efficiency range with the exhaust energy (max boost) you're going to be fighting to control the car more than just driving it to gain traction since power came so quickly. (YES, even with an LSD) Some people like that effect, others don't. Just expect it.

If simply hp level is your biggest priority, then use the GT35R. If a better powerband and torqueband is the priority, with maximum controlability, use the GT3076R.

NLR808

your stuck with the choice of going with a different manifold and turbo size at this point

hondasingapore

hi, TheShodan:

Thank for a very technical explanation esp. on the after effect of GT35R esp. mine is a daily driven honda. I esp. like your point on Port/Polish & Valve Job is "not" necessary for a FI setup.

I am still pondering about it whether to step up to GT3076R for the purpose that my car is for. Do you still think I need to junk that HKS Cast Iron Turbo Manifold to match with GT3076R?

Yeah, I am also using Eagle 89mm Crankshaft so I am not sure whether my bore & stroke is still as what you have commented. My B18C1 block is darton-sleeved with 84mm WISECO pistons.

Please help me and with your advice, I will ditch the GT35R path as I want a broader power band, etc.

Thank a lot, pal..

TheShodan

iTrader: (14)

No problem. From your comments earlier, it seemed as though you were more interested in a broader torque/powerband than simply just big HP numbers. Many people think there is a direct correlation. Sure, Torque increases with HP, but in a GT35R case, that peak torque isn't reached until the last couple thousand rpms and is not broad in range.

the GT3076R is available in an internal wastegate design for the T25 flange, and as a 44mm wastegate external for T25. the HKS isn't a bad manifold for better torque, but the GT3076R is about as large as you want to get with this HKS manifold. Can you get something that has more CFM volume like a "ramhorn"? SURE. The question is, how you want the power.

hondasingapore

TheShodan:

Thank again. Ya, I will probably pick up a GT3076R, but the ramhorn Turbo Mani may hit my full-core radiator, I think. Still researching though.

Just now, I just tested my car, turned the HKS EVC V boost setting to B-1.4 bar setting. Below is some observation with me took a close look at the Defi Analog Boost Meter: I would assume the boost will come in ONCE the DEfi boost meter shows a value GRETAER THAN 0.

Gear 1 about 6800 RPM
Gear 2 about 7000 RPM
Gear 3 about 4800 RPM
Gear 4 about 4000 RPM

My car still feels torquey before the come in of boost.

Based on the above information, I would assume my boost will come in at 4000RPM (soonest). The power band that I want probably will be 3500-4000 to my redline, 8200RPM. With the GT3076R, I may have to adjust the rev cut to higher if there is still power coming on above 8200RPM.

I already have SuperTech Dual Valve Spring & Retainer (newly installed), SuperTech Bronze Valve Guides, SuperTech Valve Stem Seals. The rest is all B18C5 OEM like valve locks, valve seats, etc.

Please feel free to comment. Appreciate any inputs.

Thanks.

TheShodan

iTrader: (14)

you're assuming that you're going to gain more power simply by increasing your RPM limit. It doesn't work that way. The exhaust energy created by the engine is going to reach maximum speed at some point so after a certain rpm, it will start to taper down.. nothing you can do about it.

Your tuner will know when to worry about maximum rpm and maximum power. But that earlier correlation is only correct to a point.

Horseofcourse

If you already have that valve train, Some Skunk2 Tuner1's would be a good cam for your current setup. I have seen some dyno charts where people would get sometimes over 50hp gains, that really depends on the tuner. A GT30 and a Ramhorn would be money.

hondasingapore

hi, all:

Thank a lot for your advices. I will plan to look for GT3076R with 0.82 turbine A/R, anyone has experience with such a big turbine A/R?

redline32

As far as your question if a full length radiator and ramhorn manifold.. answer is yes it can fit as I have both. Just request that the wastegate to the side rather then in front..just my .02$

turbo97coupe

http://www.evans-tuning.com/_images/...rhighboost.jpg

legomytego

any pictures ?

hondasingapore

Thank, pal...

TheShodan

iTrader: (14)

Yes, it will shift power very far to right of the compressor map, putting torque at a lower level in the rpm range and get more top end power at higher RPMs. You would be better with a GT35R at lower point than a GT3076R at a higher A/R turbine housing for what you're looking for.

Karl Buchka

I would be willing to bet that your exhaust backpressure before the turbine is at least twice that of boost pressure, which would explain the underwhelming dyno results. A better header, a bigger flange, and a bigger exhaust housing would do a lot to help you out.

I really don't mean to go OT pick apart an old reply, but the idea that turbo cars 'force it in' and don't need ported heads is a surprisingly common misconception. In an FI engine, the air enters the cylinder in the exact same way as in an NA engine. The only difference is the pressure differential between the chamber and the intake port. Nothing is being 'forced' anywhere.

While in practice it may be true that a FI engine is less sensitive to volumetric efficiency changes, saying that it doesn't benefit from increased VE is simply not correct.

TheShodan

iTrader: (14)

But what you're forgetting is that there is no scavaing effect needed in turbocharged applications that there are in NA applications. After several bench flow tests with 8 Honda B series cylinder heads, some P n P and some stock (or with mild work) there was about only a 20-50cfm difference. Not economically worth the additional money to invest in it. My explanation wasn't simply theoretical.

Karl Buchka

Can you clarify what you mean by "naturally aspirated engines needing scavening"?

No matter what engines you're dealing with, "20-50cfm" is hardly an insignificant increase over stock flow.

hondasingapore

so, guys, what turbine A/R would you recommend based on the following requirements?

HKS Cast Iron Turbo Manifold (as in this post)
Planned upgrade to GT3076R
Red line at 8200RPM, can be raised if necessary
Daily driven car with air-cond & power steering
Final Gear is 4.2 now
May swap to a Skunk2 cam as the folks here have good result

Of course, a retune

Thanks ... u guys rule the FI honda, 2-hands UP ...

TheShodan

iTrader: (14)

The "scavaging" effect is basically the attempt of an engine to be able to "gather" as much air as it possibly can in order to assist the compression and combustion of air into the cylinder chamber. This affect is needed in Naturally Aspirated engines because the air is only brought into the intake manifold with atmospheric pressure. Atmospheric pressure as a vacuum is what brings air into the combustion chamber for proper "explosion". In turbocharged engines, this is not as much as a concern as the air being brought into the combustion chamber is "FORCED" (Inducted) instead of gathered, so the benefits of the Porting and polishing that is performed is not as realized as in a natural aspirated vacuum.

As for 20-50cfm being a big deal, a good desk, or bath fan creates 70cfm at full speed. So, as I said, it is not big deal.

TheShodan

iTrader: (14)

The "scavaging" effect is basically the attempt of an engine to be able to "gather" as much air as it possibly can in order to assist the compression and combustion of air into the cylinder chamber. This affect is needed in Naturally Aspirated engines because the air is only brought into the intake manifold with atmospheric pressure. Atmospheric pressure as a vacuum is what brings air into the combustion chamber for proper "explosion". In turbocharged engines, this is not as much as a concern as the air being brought into the combustion chamber is "FORCED" (Inducted) instead of gathered, so the benefits of the Porting and polishing that is performed is not as realized as in a natural aspirated vacuum.

As for 20-50cfm being a big deal, Here's an example.. a good desk or bath fan creates 70cfm at full speed. So, as I said, it is not big change in performance for FI Hondas.

Back onto the OP's topic, now, ok? You can discuss this further by PM if you wish.

Drew Peacock

Well a gt2871r .84 are you sure you have the .82? Should do 400whp in a FWD no problems

You won't see much more then that reliably, I have the 2871r.64 in my s14 so rwd making 350whp I am seeing incresed knock so am moving to race gas but I don't see why with adequate tuning you shouldn't be able to hit 400whp with the turbo you have..

Are you quoting flywheel HP or power to the wheels?

TheShodan

iTrader: (14)

you can't really compare an S13 to a Honda in cylinder head design. You're correct, the S14 can do 350whp on a GT2871R (though pushed on the .64a/r), but that will not be as easy on a Honda without creating a lot of backpressure for the system. Back pressure is something that Nissan engines can operate with decently, but Hondas tend not to.