turbo D series EF/EG for autocross and track days, worth doing? vs N/A B18C

[tronic]

I'm thinking about building a new low-budget autocross/HPDE car out of an EF hatch or sedan (just to be unique) or an EG hatch. I'm pretty fluent in B series stuff, having an STS-ish 94 GSR sedan (2600lbs) I daily drive and HPDE', and from cobuilding/codriving a 10psi JRSC'ed B18C'ed EG hatch (2200lbs) in SM autocross class. I don't know too much about D-series engines and haven't turbo'ed a car yet but have been wanting to. I figure I'd be happy with 180-200whp. I'd be using 255/40-13 Hoosiers for autocross in the front, and 225/45-15 Hoosiers for track days. So I figure I can afford to do a basic D-series turbo setup on a stock engine, maybe Greddy 15g based, later upgrading to a Garrett GT28RS and built block.. -OR- Do an N/A B18C1 swap for about the same cost. Later doing pistons, cams, headwork, etc, to get to that 180+whp mark. I do like my DOHC VTEC. Any thoughts either way? I can't convince myself that a turbo D series would be fast enough and be anything other than anemic at low RPMs until the boost hits, then it'd be peaky and hard to control VS a naturally aspirated B series. More torque with the turbo, though. D series drivetrain would be lighter by what, 100lbs? Reliability would be easier to achieve with the NA B series, I'm concerned about that for track days mostly. Has anyone had success with a turbo D series in autocross?

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[thawley]

If a swap is an option and you want to keep it low-bux, I'd say a B20 would be a better option than a turbo or a GSR engine. Especially for auto-cross.

Extra bonus points if you use a portion of the money you save and get a pair of BC stage-II cams.

[G'Funk]

TRONIC!!!!!!!!!

haha.

man i'm just telling you from things ive seen with my friends. turbo d-series = waste of time. no torque, and SO many issues...the money you waste turbo'ing the d series just to get the same or less power than a B18C1, when you could have just used that money to get the B18 to begin with. and im not sure about the benifit of less weight with the drivetrain, because with all the added weight with the turbo set-up.

i would say if anything, either B20, or LS. you can get LS for way cheap, they have high torque for a b series, and you can easily get a vtec head and do the LS/Vtec setup and have yourself a lot more potential. or do the B18C1, but i honestly thing the B18B would be much more fun.

but if you only choosing between the 2, get the B18C1

and lemme help put it in hahaha

[unrealwrc]

no way skunk 2 pro 1 cams are the way to go on stock b20vtec

[thawley]

Originally Posted by unrealwrc

no way skunk 2 pro 1 cams are the way to go on stock b20vtec

I never said VTEC. Nor will I. The stock B20 with B20 head and the BC Stage-IIs is a brilliant combination for street and autocross. And with complete B20s going for $550 in SoCal, pretty hard to beat value-wise.

As a side note (since I've not said it in a while) the day I stopped liking my Civic/LS swap was the day the VTEC head went on. Yes it made more power, and yes it was properly tuned (by Hondata at Church's dyno), but it never had the same drivability and was never as much fun (for me) on the street. Since I pulled the LS/VTEC out and put in a stock B20, I've been much happier.

Reasonable minds may differ

[unrealwrc]

Originally Posted by G’Funk

TRONIC!!!!!!!!!

man i'm just telling you from things ive seen with my friends. turbo d-series = waste of time. no torque, and SO many issues...the money you waste turbo'ing the d series just to get the same or less power than a B18C1,

LIES turbo D is not a waste of time, i have seen $300 junkyard turbo kits for d series make 220+whp(friends civic). the weight after turbo kit is about the same as the B.

things you get better with the B is the NA power and constant power band. but the D IS ALLOT CHEAPER to make fast. B you will most likely only see 180 from for the swap and you already have a stock D.

O and BTW i made a small turbo kit on a D that made 144whp and 148wtq ($300)... but was severly outclassed in everything because I was turboed.

I say don't listen to G'Funk for the reasons not to go D but it comes down to preference of Turbo D or NA B. after being a turbo D for 2 years I switched to NA B at the same power and I like it alot more... gearing, higher rpm, na powerband.


Modified by unrealwrc at 12:51 PM 8/12/2008

[unrealwrc]

Originally Posted by thawley

I never said VTEC. Nor will I. The stock B20 with B20 head and the BC Stage-IIs is a brilliant combination for street and autocross. And with complete B20s going for $550 in SoCal, pretty hard to beat value-wise.

Reasonable minds may differ

you will love the torque of the b20. just throw a b16 trans on it. (tighter gears) +1 for B20 stock or not.

I do love my vtec b20 at 201 whp/148wtq though

[G'Funk]

im glad you had a great experience with your d-series. no need to bash bud.

i have 4 friends that all tried to "save the single" they all had boosted d-series. the 2 that did the cheap backyard turbo special had the most unreliable cars. and tronic wants it for his daily as well. the 2 that spent the money on quality parts, ya they had a reliable car, but the amount of money you could have gotten an LS and swapped it in, and for a little more gottan a B18C1. and even as you mentioned the gearing on d-series compared to B's....

and of the 4 I beat 3 of them in my EG (DX) N/A B18C1 with ITR tranny. the only one that beat me was another EG (CX - lighter model). now 3 of the 4 have switched to B's, and the other sold his car and bought an GSR.

im just sharing my experience. im sorry if i offended anyone. in my opinion D-series is a waste. much more potential with a B, so why not start where you will have the most potential and more fun in the long run?

[Lo-Buck EF]

having driven it all, turbo d and b suck for autocross unless you have 275s up front.
turbo honda track cars suck. the only person i know that is still happy with his is don (yack's boy)

[tronic]

Thanks for the input guys! You've pretty much talked me out of a turbo D series.

I guess I should say I'm familiar with B18C1, B18C5, B18B1, and B16A engines.. not so much B20, B20VTEC or LSVTEC setups..
I really like the high rev limit of the VTEC engines for autocross. Doesn't it take a good deal of work to make a B20 or B20VTEC rev past 8000? (as in I might as well start with a B18C block..)

I am leaning towards the EG chassis so I can swap my DB8 Integra's suspension over and so the B-series swap would be more straightforward than with an EF.

[K2e2vin]

For autocross, why not a naturally aspirated D? Quite a few guys are around 140-150whp with pretty simple parts/not much money. I'm pretty sure a stock B16 and B18B is around those numbers or even less.

[unrealwrc]

IMO, the stock b16 swap isn't really worth the move from a z6. the weight/power gain does not benefit the car. Infact just makes the front end heavier by 100+lb's.

plus z6 gearing is pretty good and you will get better gas mileage and cheap parts can get them to 140-150. although you won't be able to push them much further then that.

O and how are you familiar with the B18's and B16's but not the b20's? still almost identicle engines... hence beeing a B. nothing is really different with the B20 or more abnormal then what you would find in the B18's

[Bisimoto]

D, all the way!

[Aquafina]

A6 gearing is far from good (he has a cable car). About the same as a hydro LS/cable 92-93 LS.

Throw a close gear set in it and that takes care of the gearing. My close gear set is by far the best item I've purchased for my D. Makes so much of a difference on track. I can't wait to see what it will do with an LSD.

close gear set, D17 crank, decent turbo setup and it will be fun.

A question, are you building it to be competitive or just for fun? That should play a big role in how you build it.

[joenationwide]

ive autoxed my friends turbo d-series eg, and it was fast! (2nd FTD). I think a T25, so it had no lag. it puts down 215whp, 250tq. built for autox. ran it with 225s, but 275s up front i think it could be nationally competitive.

also autoxed a b20 eg 4-dr. had great torque, which id say is a better autox engine than a b18c1, maybe even b18c5. of course gearing is important too, you want a loooong 2nd gear with a b20, so maybe an LS tranny.

somethings that will work well in autox will not work well on track.

for autox:

small turbo d, or b20 is nice
long 1st and 2nd gear is good
lsd (especially on street tires)

for track:

na is more reliable, especially b18c motors, top end is key
b16 or type r tranny is waaay better than ls, or gsr tranny (they suck on track)
lsd is pretty important especially on street tires.

[hybridmoments]

turbo d is a great setup for autox. however it is unfair to compare to other setups, as a majority of people with D's cheap out and do not build or tune them properly.
You have to properly setup a car for what you are using for.
most people building turbo d's are putting t3's and larger turbos on. this is stupid for autox as you aren't going to be seeing 6k rpm and up more then maybe 10% of the course. you need a very Meaty torque curve, so it's going to require a small turbo, especially for a 1.6 liter engine.

i built the turbo D car above in which joenationwide speaks of (which is actually currently for sale for a steal of a price).
it's just a td05b greddy turbo at 15psi. all custom except for the MHI turbo, greddy cast manifold, greddy cast downpipe elbow. with the current intercooler, driving on the street the IAT's never get above 105 degrees on a 85 deg. day. i never datalogged after an autox run. i'm sure they are much hotter.

The car dynoed 200whp and 230wtq on Dynapack at 14psi. The downpipe elbow is choking it from making HP past 4500rpm, so hp never peaks above the Tq peak, and the Tq actually never gets to hit peak.
since owner is selling car, i haven't made him a new downpipe.

If the greddy downpipe elbow was removed and replaced with a custom 2.5"to 3" downpipe, the car would be making more along the lines of 250whp/240wtq. with no noticeable lag. it feels like a BMW S52 3.2L was swapped into a civic.

sure 250whp doesn 't sound like much to most people that want to Turbo a car, but it's all about powerband for autox. you just aren't going to be able to mbuild a 400whp capable turbo D series that will have a suitable powerband for autox. any turbo adequate for autox is just not going support much more then say 280whp. the more you upsize to hit higher #'s, the more it's going to hurt your powerband.


the powerband is so meaty and linear, and torque so available from any throttle position, that the owner even wanted to ditch the EX trans in favor of a DX trans so he could extend the mph in 2nd gear and keep a lower redline.
The car is very driveable. it's powerband is fairly linear so it doesn't spin tires everytime you hit the throttle either.




Modified by hybridmoments at 11:30 AM 9/5/2008

[unrealwrc]

Ok if its properly set-up the D series turbo can be great but the class that puts you in compared to a NA B is allot different. therefore if you wanted to be competitive (although you have the power) you have to have an extremely well tuned chasis(suspension, brakes, tires all that jazz). stick B or na D and you can see allot cheaper competition and allot more wins.

I wana see the dyno charts of that Turbo D by the way.

[hybridmoments]

here is the dyno. it was only tuned to 15psi. the turbo is just about maxed, but it's not choking off because of that, it's due to the downpipe elbow. the greddy downpipe elbows are crap and just choke up the setup.
there is nothing crazy about the setup. i built the engine with some SRP +.5mm pistons. minimal head porting. stock valvetrain. about 9.1:1 compression due to necessary block deck and head deck cleanup.
Hondata S300 engine management.

Turbo was rotated from stock orientation to really minimize tubing lengths. i'd say there is only about 5 feet of tubing from turbo to throttle body. all 2.25" piping. conservative ignition timing.

Look how badly it chokes right at 5k rpm. it dies there, tries to build back up a few more whp, then dies again loses a few whp. HP never exceeds Tq, pretty crazy.of course it's dynapack. so it's going to read higher then other dynos. but the powerband is really the important part.

[solorex]

Originally Posted by thawley

As a side note (since I've not said it in a while) the day I stopped liking my Civic/LS swap was the day the VTEC head went on. Yes it made more power, and yes it was properly tuned (by Hondata at Church's dyno), but it never had the same drivability and was never as much fun (for me) on the street. Since I pulled the LS/VTEC out and put in a stock B20, I've been much happier.

Reasonable minds may differ

Interesting to hear this, I put a stock B20z in my CRX this year with a short ratio cable tranny. This combined with the 13" race wheels makes the car an absolute riot at autox and especially hill climbs. Granted I seem to be getting a fair amount of valve float above 7k rpms with the stock cams and valve train, but it's making me wonder to not go to a Vtec head and just do the cams/spring/retainers.

[Stinkycheezmonky]

Originally Posted by solorex

and just do the cams/spring/retainers.

That's your problem. Sort of. High-mileage stock valvesprings (non-VTEC) can have issues with "wearing out." The other problem is that you're not making power above 6800rpm or so anyway (and so shouldn't be revving higher than that...*cough*), so you don't REALLY need to worry about it (again, if you're not doing it...). Keep in mind too that your rod bolts MAY not like it at 7000+rpm. If they've never been apart, you're probably ok.

Originally Posted by unrealwrc

Ok if its properly set-up the D series turbo can be great but the class that puts you in compared to a NA B is allot different.

He'd be in SM either way. Without much prep, the car's going to get it's ass kicked regardless of the motor. If he's not serious about competition (I'm guessing not, based on the "low budget" comment), who cares about classing?

[SuperTwinz]

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[K2e2vin]

That's a little different than autocross; autocrosses are lower speed and tighter turns(so less time for spool ups).

[thawley]

Originally Posted by solorex

Interesting to hear this, I put a stock B20z in my CRX this year with a short ratio cable tranny. This combined with the 13" race wheels makes the car an absolute riot at autox and especially hill climbs. Granted I seem to be getting a fair amount of valve float above 7k rpms with the stock cams and valve train, but it's making me wonder to not go to a Vtec head and just do the cams/spring/retainers.

That's what I'd do.

And if cams weren't allowed in your class I'd say do the valve springs anyway. Very often in rally and auto-x, it makes more sense to stay in a gear past the power band just to avoid shifting. If you're only past 7000rpm for a few seconds before the next turn, its often faster NOT shifting up and then having to downshift again. Its easier on the gearbox, too.

You just gotta be sure you're not gonna tag a valve while doing so. That can really slow you down.

[Power2r]

I know you can make a D series really fast in AutoX, but will it be competitive with the turbo on there? What class would you have to run in?

Here in South Florida we race in a Road Racing Series called FARA, and there is a huge penalty for being turbo. By having a Turbo 1.6 liter they bump you up into a class with 2.5 to 3.6 liter cars. You end up having to race some Porsche and other cars.

[tronic]

Good info in this thread, thanks guys.
Rather than live with a raced-out Civic and hating it every day I'm NOT racing it I've decided to keep playing with my 94 GSR sedan. I love autocross but am not that interested in being nationally competitive- I am experienced enough to know what that takes, car-wise and driver-wise.

So I've got a Greddy turbo kit I'll be customizing and putting on later, and an Autotech Wavetrac LSD-equipped GSR trans on the way. Should be fast and fun enough for me, and I get to keep my stereo, alarm, cruise control, sunroof, and AC!