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-   -   Forged bottom end get in here!!! (https://www.miataturbo.net/engine-performance-56/forged-bottom-end-get-here-47198/)

na8psi 05-09-2010 07:42 PM

Forged bottom end get in here!!!
 
Just finished my 1.8 turbo setup, but its on a limited stock engine and is daily driven. Im in the market for building me an eventual replacement 1.8, not planned for but capable of being daily driven, but im new to engine building/planning and searching the forums has only gotten me so far, Ive looked around at different con-rod and piston combos, prices, "claims" of each products, and price comparisons between the products. What im looking for is suggestions from the experienced forged crowd.

Planning for,
MS1 Standalone (current engine management)
550cc injectors
190hp fuel pump
T3 .50 trim (current turbo)
99 head (unsure of cam/valvetrain combination, open to suggestions :bigtu:)
18-20psi with water/meth injection. 280+whp range is the goal :x:
83.5mm bore
8.5-9.0 CR (in this range)

ARP Fasteners
BEGi Intake Manifold
etc etc...

If my above hardware plans arent capable of such goals, do correct me and leave a suggestion!

Just really wanting to find out peoples opinions/suggestions on different rod/piston combinations that are capable of my goals and the legitmacy of each products "claims" of reliability and power as well as good price.

magnamx-5 05-09-2010 10:06 PM

sounds feasible to me. put a dual feed fuel rail in there for insurance and you should have no problem.

na8psi 05-09-2010 10:22 PM

I'm really interested in learning about the advantages and disadvantages of going with 84mm bore over 83.5mm other then slight displacement bump? Is a stock head gasket still compatible?

miata2fast 05-10-2010 07:55 AM

I am pretty sure that 84 mm is the limit that you could bore and use a stock head gasket. It is what I have, and the gasket appears to barely fit.

Another advantage of having a larger bore size is that the cylinder head flows better. There is a larger gap from the edge of the valve to the bore walls, so the air/fuel charge is not dammed up by the cylinder walls.

If you plan on doing any significant head work, with larger valves, I would strongly consider going to a larger bore size than 84 mm. Head gaskets are available for the larger bore sizes.

na8psi 05-13-2010 01:29 PM


Originally Posted by miata2fast (Post 570462)
I am pretty sure that 84 mm is the limit that you could bore and use a stock head gasket. It is what I have, and the gasket appears to barely fit.

Another advantage of having a larger bore size is that the cylinder head flows better. There is a larger gap from the edge of the valve to the bore walls, so the air/fuel charge is not dammed up by the cylinder walls.

If you plan on doing any significant head work, with larger valves, I would strongly consider going to a larger bore size than 84 mm. Head gaskets are available for the larger bore sizes.

No plans for significant head work, simply a 99 head swap and simple deshrouding. New valve seals, and aftermarket valve springs and retainers and call it a day.

webby459 05-13-2010 01:31 PM

Carrillo rods, FM/Wiseco pistons, burn E85.

Jeff_Ciesielski 05-13-2010 01:51 PM

Aside from recommending larger injectors, if you couldn't hit 280whp WITHOUT meth on that setup @ 18-20psi I would have to say that you are doing something wrong. I made 235whp on that same turbo on a 1.6 @12psi, 20 psi on a 99' 1.8 should net you closer to 350whp+. To be honest, I'm fully expecting that with my new manifold/downpipe/exhaust I will be right around 250whp @12psi. You need to assess your tune.

cueball1 05-13-2010 02:04 PM

What he said.

Your power goals are modest for the set up you are describing and you'll likely hit them under 18-20psi.

Jeff_Ciesielski 05-13-2010 02:08 PM

OP -> post your timing map for evaluation and ridicule.

:D

18psi 05-13-2010 02:15 PM

you have a decent list. You have a realisitic goal. everything sounds good. Now to assemble everything properly and then tune it all properly and you're set.

Aero91 05-13-2010 03:00 PM


Originally Posted by Jeff_Ciesielski (Post 572321)
Aside from recommending larger injectors, if you couldn't hit 280whp WITHOUT meth on that setup @ 18-20psi I would have to say that you are doing something wrong. I made 235whp on that same turbo on a 1.6 @12psi, 20 psi on a 99' 1.8 should net you closer to 350whp+. To be honest, I'm fully expecting that with my new manifold/downpipe/exhaust I will be right around 250whp @12psi. You need to assess your tune.



did you use the same dyno?

my 92 9000 dynoed 265whp and 330ftlbs on a dynoject, and then a few months later running the same configuration, it did 235whp and 286 ftlbs on a mustang dyno;)

Jeff_Ciesielski 05-13-2010 03:01 PM


Originally Posted by Aero91 (Post 572368)
did you use the same dyno?

my 92 9000 dynoed 265whp and 330ftlbs on a dynoject, and then a few months later running the same configuration, it did 235whp and 286 ftlbs on a mustang dyno;)

Mine was on a dynodynamics, which by all accounts I've heard reads lower than your average dynojet.

fooger03 05-13-2010 03:02 PM

coolant reroute before dual-feed fuel rail

miata2fast 05-13-2010 03:57 PM


Originally Posted by na8psi (Post 572307)
No plans for significant head work, simply a 99 head swap and simple deshrouding. New valve seals, and aftermarket valve springs and retainers and call it a day.

If you plan to run the stock cam or a very small upgrade, I would not change the valve springs. Stiffer valve springs should only be used if they are needed to control a very high reving motor from a cam with a lot of duration and lift. If you have budgeted for valve springs, I would go with new valves with undercut stems instead, and ditch stiffer valvesprings. You will not need to fool with the valve seat (other than lapping) and you will get a little better air flow.

Stiffer springs will do one thing for you if you have not upgraded the cam. Rob Horsepower!

You may also consider using shim under lifters. They are much lighter than stock, and will net you a little more power.

Edit: Considering your goals, stick with the smallest overbore. We want to keep as many viable blocks around as possible at the rate we are blowing them up.

na8psi 05-13-2010 06:28 PM

1 Attachment(s)

Originally Posted by miata2fast (Post 572396)
If you plan to run the stock cam or a very small upgrade, I would not change the valve springs. Stiffer valve springs should only be used if they are needed to control a very high reving motor from a cam with a lot of duration and lift. If you have budgeted for valve springs, I would go with new valves with undercut stems instead, and ditch stiffer valvesprings. You will not need to fool with the valve seat (other than lapping) and you will get a little better air flow.

Stiffer springs will do one thing for you if you have not upgraded the cam. Rob Horsepower!

You may also consider using shim under lifters. They are much lighter than stock, and will net you a little more power.

Edit: Considering your goals, stick with the smallest overbore. We want to keep as many viable blocks around as possible at the rate we are blowing them up.

hahaha never can have enough good 1.8 cores floating around can we.

MSQ posted for your elegant but experienced ridicule! lol if I did not load the right file or did something wrong do tell lol, I've never just loaded a spark map alone to here.

Jeff_Ciesielski 05-13-2010 06:34 PM

I see your problem.

Your spark map:
http://lh6.ggpht.com/_tMYIeupe-9Q/S-...map_na8psi.JPG

My spark map:
http://lh4.ggpht.com/_tMYIeupe-9Q/S7...dynotiming.png
(Sorry for the shitty, uncolorized format)

Notice the curve it has? It ramps up during spool up, then drops down towards peak torque (to prevent knock) it then ramps back up to keep torque flat(ter) till redline.

Note: If you use this and blow your shit up, I hold no responsibility for it. This works well in my car, but I have reason to believe that other people might not be as fortunate.

na8psi 05-13-2010 07:19 PM


Originally Posted by Jeff_Ciesielski (Post 572484)
I see your problem.

Your spark map:
http://lh6.ggpht.com/_tMYIeupe-9Q/S-...map_na8psi.JPG

My spark map:
http://lh4.ggpht.com/_tMYIeupe-9Q/S7...dynotiming.png
(Sorry for the shitty, uncolorized format)

Notice the curve it has? It ramps up during spool up, then drops down towards peak torque (to prevent knock) it then ramps back up to keep torque flat(ter) till redline.

Note: If you use this and blow your shit up, I hold no responsibility for it. This works well in my car, but I have reason to believe that other people might not be as fortunate.

Damn, I appreciate the insight. Definitely noticed the curve in the spark map now that its been pointed out to me, I've never had any experience with tuning or looking at spark maps. So I could definitely pick up some power on the big end with proper ignition tuning?

Jeff_Ciesielski 05-13-2010 07:26 PM


Originally Posted by na8psi (Post 572500)
Damn, I appreciate the insight. Definitely noticed the curve in the spark map now that its been pointed out to me, I've never had any experience with tuning or looking at spark maps. So I could definitely pick up some power on the big end with proper ignition tuning?

You'll pick up power EVERYWHERE with proper ignition tuning, plus have better spool = even MORE under the curve. Timing is the key to making power, but be careful, because more often than not it is also what kills motors when you get careless.

na8psi 05-13-2010 08:59 PM


Originally Posted by Jeff_Ciesielski (Post 572504)
You'll pick up power EVERYWHERE with proper ignition tuning, plus have better spool = even MORE under the curve. Timing is the key to making power, but be careful, because more often than not it is also what kills motors when you get careless.

Jeff could I possibly steal a peek at your MSQ?

webby459 05-13-2010 09:29 PM

http://farm2.static.flickr.com/1151/...32871078ce.jpg

:giggle:

Granted, my motor is sitting on my garage floor and may be scrap, but not due to tune or fueling or anything...


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