Dyno Shootout: Battle between Dinan and RD Sport for 4.6 Liter Stroker Motor Braggin

[CSBM5]

So the problem on the Dinan S65 stroker was related to throttle bodies not opening fully and timing not properly advancing? Other than that linked post, I've not seen it updated anywhere else. What is the status of the Dinan stroker at this point?

[regular guy]

Originally Posted by CSBM5

So the problem on the Dinan S65 stroker was related to throttle bodies not opening fully and timing not properly advancing? Other than that linked post, I've not seen it updated anywhere else. What is the status of the Dinan stroker at this point?

Not sure the status. I know the owner has the car back. That's all I know. We had a very small window for a rematch, but one of the owner's was on vacation and out of town that week. So I wouldn't expect a rematch until early 2014.

[Triple M]

An excellent job well done Alekshop!!!!!! And God bless dyno!!!,
I am not surprised by these findings. I have has my suspicion ever since the initial C/D testing, and even more importantly forum members disappointing dyno numbers on a 25K transformation. I'm glad you guys finally put it to the test. Old tune or new, should a tune degrade over time and cause a loss in HP ? Again, it's the 25K question, explain that to the guy who dropped the cash. Check this out:

http://www.m3post.com/forums/showthread.php?t=798738

As far as going fast, well to each in its own. Spend enough time on the track and you'll see a stock E92 M3 eat a highly modded e92 alive in the hands of a capable driver (Damn spec miatas as well.lol). On the road, which I don't advice (RIP Paul Walker), nothing more disheartening than being torn apart by 800whp JDM (in our now 80-100K M3). At the end of the day, driver mod can be one of the best money well spent.

[Triple M]

This was the one that first got me thinking:

http://www.m3post.com/forums/showthread.php?t=381227

[Yaw]

Originally Posted by Triple M

An excellent job well done Alekshop!!!!!! And God bless dyno!!!,
I am not surprised by these findings. I have has my suspicion ever since the initial C/D testing, and even more importantly forum members disappointing dyno numbers on a 25K transformation. I'm glad you guys finally put it to the test. Old tune or new, should a tune degrade over time and cause a loss in HP ? Again, it's the 25K question, explain that to the guy who dropped the cash. Check this out:

http://www.m3post.com/forums/showthread.php?t=798738

As far as going fast, well to each in its own. Spend enough time on the track and you'll see a stock E92 M3 eat a highly modded e92 alive in the hands of a capable driver (Damn spec miatas as well.lol). On the road, which I don't advice (RIP Paul Walker), nothing more disheartening than being torn apart by 800whp JDM (in our now 80-100K M3). At the end of the day, driver mod can be one of the best money well spent.

So your impressed with a comparison where one of the engines is not operating at full throttle? Interesting. Very much waiting on the updated dyno numbers myself.

[Someone?]

Originally Posted by Yaw

So your impressed with a comparison where one of the engines is not operating at full throttle? Interesting. Very much waiting on the updated dyno numbers myself.

Yah Dinan is Top Notch so im looking forward to seeing the Dinans engine true numbers.

[Triple M]

Originally Posted by Yaw

So your impressed with a comparison where one of the engines is not operating at full throttle? Interesting. Very much waiting on the updated dyno numbers myself.

I'm impressed with the amount of time Alekshop took to give the rest of us who can't just grab two stroker engines (by 2 reputable companies) at will and get them dynoed same day. Don't get me wrong, I love Dinan product bought tons of them under warranty), but if I'm dropping 25K on a motor, hope I don't have worry about throttle issues (especially since I can't keep traveling back forth to them). I can't wait for the updated dyno number either, hope the update won't require another update.

[CSBM5]

Originally Posted by regular guy

Not sure the status. I know the owner has the car back. That's all I know. We had a very small window for a rematch, but one of the owner's was on vacation and out of town that week. So I wouldn't expect a rematch until early 2014.

Update?

[regular guy]

Originally Posted by CSBM5

Update?

Guy with RD Sport stroker is up for a rematch. I spoke to him recently. I haven't heard from the guy with the Dinan stroker. Let me try a little harder to get in touch with him.

[DavidZ]

No offense, but it seems pretty silly to me to do all that work on the bottom end and leave the head untouched. These guys know how to build a proper stroker.

[regular guy]

Originally Posted by DavidZ

No offense, but it seems pretty silly to me to do all that work on the bottom end and leave the head untouched. These guys know how to build a proper stroker.

I'm not sure if you've ever seen the heads from the S65. They are CNC ported from the factory. It's quite possible that hand porting might actually cause more harm than good. Before I trusted anybody to port these heads, I would make sure they had laser mapped them, then cut one apart to see how close the ports are to water and oil. I wouldn't trust anybody to touch these heads if they didn't do those two things.

Once you have the ports properly mapped and know how close they are to water and oil, then porting could be done. Again here, I would only trust it to be CNC ported again and based on the laser mapping. How much to port depends on what you're trying to accomplish. There's no free lunch here for an NA motor.

[Jbook]

Originally Posted by regular guy

Guy with RD Sport stroker is up for a rematch. I spoke to him recently. I haven't heard from the guy with the Dinan stroker. Let me try a little harder to get in touch with him.

I have his number if you want me to try. I was there that day and want to get my car on the dyno again with the new setup as well as witness the rematch.

[regular guy]

Originally Posted by Jbook

I have his number if you want me to try. I was there that day and want to get my car on the dyno again with the new setup as well as witness the rematch.

Yes please. I contacted him today and he also confirmed as well. I think I'd like to do this in the next two weeks. Let him know that let's try for February 15th -- provided the dyno shop will open on a weekend again. To make it as controlled as possible, I'd like to use the same dyno shop as last time.

[chungdae]

Wow. I expected much more power gains from the stroker motors over stock.

[Hujan]

Originally Posted by chungdae

Wow. I expected much more power gains from the stroker motors over stock.

Yup. Has to be the worst $/HP value of any mod.

[regular guy]

Originally Posted by chungdae

Wow. I expected much more power gains from the stroker motors over stock.

There is a 15% increase in displacement. Why would you expect more than a 15% increase in power? I've never understood that.

The RD motor started at 338whp, and tested that day at 390whp.
Gain = 390 / 338 = 15.4% gain.

That 15.4% gain is right on target with expectations. Whether it's the best hp mod for the money is a different question. Each owner has their own criteria. The owner of the Dinan motor had a supercharger first, then sold it and built a stroker. He tracks his car regularly, and that was part of his calculus for the decision.

[DavidZ]

Originally Posted by regular guy

I'm not sure if you've ever seen the heads from the S65. They are CNC ported from the factory. It's quite possible that hand porting might actually cause more harm than good. Before I trusted anybody to port these heads, I would make sure they had laser mapped them, then cut one apart to see how close the ports are to water and oil. I wouldn't trust anybody to touch these heads if they didn't do those two things.

Once you have the ports properly mapped and know how close they are to water and oil, then porting could be done. Again here, I would only trust it to be CNC ported again and based on the laser mapping. How much to port depends on what you're trying to accomplish. There's no free lunch here for an NA motor.

Did you see my link? I wasn't talking about a port/polish necessarily. I was talking about cams, valves and valve springs, which last I checked were in the head.

[regular guy]

Originally Posted by DavidZ

Did you see my link? I wasn't talking about a port/polish necessarily. I was talking about cams, valves and valve springs, which last I checked were in the head.

Of course I saw the link. Apparently you want me to say I'm impressed that somebody knows how to install cams and valve springs. It takes much more than that to impress me.

You can thank me that all these guys know where to get the aftermarket valve springs. It was my guy who designed them, and I was the guy who called up a bunch of engine builders and gave them the part numbers and told them where to order. My same guy who designed these valve springs did the engine design work for Rahal ALMS team. At that time, he had already designed and tested cams on their S65 race motor. He told me that cams did very little for this engine; they only gained 10-12 CHP on their 4.0L race engine. So far, I haven't seen any dyno results to prove otherwise.

Given the valve design in this head, I think there's very little to be gained by shaving the stem, or anything else these guys have said they are doing. My question to you: have you seen this engine apart? Have you seen the pieces yourself to see how little room there is for improvement?

I'm impressed by proper engineering work (as described earlier) and by actual dyno results than by anything else.

BTW, both of these motors in this shootout had the aftermarket valve springs installed. A buddy of mine is doing a stroker build right now with cams. After he's done, we'll do a shootout against all three of these cars. Then we can see how much cams did to help.

[DavidZ]

You still don't seem to understand what I'm saying. My original statement said "it seems pretty silly to me to do all that work on the bottom end and leave the head untouched." You then mention porting. I then mention cams. You then talk about cams on a 4.0 liter engine. I'm talking about cams + stroked engine. My point is the combination of both could be far greater than each alone. It doesn't make sense to me to run a stock head on a modified bottom end or a modified head on a stock bottom end. If you're going to build a motor, build the whole motor. I haven't even looked into the specs of aftermarket cams for the S65, but I'd assume they get more air into the cylinder via more duration, lift or aggressive opening and closing profiles. That's just what the increased volume of these strokers need, right?

[catpat8000]

Originally Posted by DavidZ

You still don't seem to understand what I'm saying. My original statement said "it seems pretty silly to me to do all that work on the bottom end and leave the head untouched." You then mention porting. I then mention cams. You then talk about cams on a 4.0 liter engine. I'm talking about cams + stroked engine. My point is the combination of both could be far greater than each alone. It doesn't make sense to me to run a stock head on a modified bottom end or a modified head on a stock bottom end. If you're going to build a motor, build the whole motor. I haven't even looked into the specs of aftermarket cams for the S65, but I'd assume they get more air into the cylinder via more duration, lift or aggressive opening and closing profiles. That's just what the increased volume of these strokers need, right?

I think it is fair to say that while aftermarket cams may not do much for the S65 in stock config, they may have much more effect on a stroked motor, especially since most of the dyno graphs I've seen of the stroker motors have a significant drop in torque at higher rpm, relatively more than the stock S65. This implies there is HP left on the table.

Anyway, as RG said, he does have a buddy who is building a stroker and that buddy is going to try out the Schrick cams which have increased duration and lift so there will be some data on this at some point. I'm quite excited to see how his build goes.

Pat

[regular guy]

Originally Posted by DavidZ

You still don't seem to understand what I'm saying. My original statement said "it seems pretty silly to me to do all that work on the bottom end and leave the head untouched." You then mention porting. I then mention cams. You then talk about cams on a 4.0 liter engine. I'm talking about cams + stroked engine. My point is the combination of both could be far greater than each alone. It doesn't make sense to me to run a stock head on a modified bottom end or a modified head on a stock bottom end. If you're going to build a motor, build the whole motor. I haven't even looked into the specs of aftermarket cams for the S65, but I'd assume they get more air into the cylinder via more duration, lift or aggressive opening and closing profiles. That's just what the increased volume of these strokers need, right?

When most people talk about touching the heads, they mean porting and polishing. Most people and engine builders consider cams and valve springs are bolt in items. Regardless, both engines do have the upgraded valve springs. Now that I see what you're talking about, you might want to ask the car owners why they made the decisions they did. I'm pretty sure the RD engine was built before cams were available -- so that would explain his decision. Dinan will put cams in if you want.

Let's assume a wildly optimistic gain on stroker cams of 25 CHP. I guess you'd have to ask if the extra $2500 in hardware + extra $2000 in software is worth the extra 25 HP of power. I had the opportunity to have custom cams done for a LC blown stroker. The cam was designed for the S65 by the same who designed the valve springs. Since it was a custom grind, the costs were going to be about $4500 to have Schrick grind them for me. At the end of the day I weighed the same cost-benefit options. I ultimately decided it wasn't going to be worth the price to me.

The point is, these are all personal choices that we individuals make on our own. The RD guy likely didn't have the choice. The Dinan guy had the option, as did I. We both decided it wasn't worth it. You're free to disagree and build your own stroker to your own specifications and post the results when you're done.

[DavidZ]

Well VAC does have a dyno chart to back up their 4.4/Schrick stroker, although it's an engine dyno, with standalone engine management and 100 octane gas. 539 HP and 394 TQ at the crank. Those were mild cams. Supposedly an engine with higher compression and more aggressive cams made 570 crank HP, still at 4.4L. I'll be getting a stroker built soon and will be installing it in my car when my warranty is up in 2015. Threads like these are where I'm doing my research on where and how to get it built. I was already leaning away from Dinan but now I've pretty much ruled them out.