We all know the story of Maxpeedingrods coilovers. Has anyone here tried their connecting rods? They are just about the only option for the 7A-FE bottom end in my old MR2, and assuming quality is good, the price seems fair. Stock rods are on borrowed time with my current combination and I'd like to prep for higher RPM and/or boost.
The only "feedback" I've seen is mostly just sponsored unboxing videos where the host admires their beauty. Not exactly probing their limits. Anybody have any firsthand experience or even exposure?
Someone will suggest I just spend money and get real rods from an established brand name. Sadly, even if budget permitted, it's not really an option. This engine just doesn't have a lot of aftermarket support.
In this video their weights and tolerances are checked. Also they say these rods are TUV certified:
Paging oldeskewltoy...oldeskewltoy to the courtesy phone...😁
If anyone knows the answer, he would be the one.
I've tried the various China rods in several Honda by in large they're fine just copies of old Eagle H beams. This is one where you are trading money for time you must carefully inspect and measure these parts before using them I have to assume the quality control is lacking at best.
If it's an engine where there is much to copy I'd be more hesitant, engineering is not the Chinese job shop's strong suit as we know.
Thanks for the input on the Honda experience. The engine - the bottom half, anyway - is a Toyota 7A-FE. Dimensions have been known and published for decades, so nobody should have to do any reverse engineering.
Gameboy, thanks for the video. I watched what I could of it last night. D4A has some decent content, and I don't think he's deceptive or untrustworthy, but that's also (as most are) a sponsored video that is really a marketing effort.
I know I'm asking a lot. Most people who are prone to push limits are not likely to buy off-brand rods. Even the stock rods, which I usually refer to as stained glass, have held up way better than I expected them to.
I didn't have any concerns about the quality of the machining on the coilovers. But metallurgy is so important to rods and there's more to a strong rod than just basic dimensions. Check out the LS3 failure in JG's Corvette, that was an LS rod which is not exactly a new application. But someone (I don't think we know the brand) wasn't able to design/build a rod that could handle the tensile loads.
If the engine is a fairly common one so that it's not that big a deal to have one grenade, I'd gamble on them. I think they get used in cheapo Miata builds. But if you don't like building engines, or if there are unobtanium parts in this one, I'd be calling Carrillo and seeing what they could do for me. We used to have them make custom rods for our stroker kits.
https://www.cp-carrillo.com/files/1-Landing%20Pages/Rods/pdfs/sp-72-01-rev-a-standard-spec-sheet-1.pdf
^ Exactly. Metallurgy is not the same as dimensional accuracy. Strength is not the same as aesthetic appeal.
Keith, talking to Carrillo is a smart suggestion, but the budget just ain't there.
There may be another option that I'd previously explored and forgotten about. Still, I would like to continue this discussion in case anyone here has actually rolled the dice on the dingrods and either lived to tell the tale or not.
Opti
UltraDork
3/22/24 12:40 p.m.
In the SBC pretty much all of the mid tier stuff is forged in China and then sometimes final machining is done here. In my experience, the guys that check stuff closely find all kinds of weird things, even from the big names, and the guys that dont check stuff tend to stuff them in and run them without problems (not saying they never fail). They are advertised as 4340, which is good if thats what they are.
Id run em, and I MIGHT even check them.
Sitting on my desk right now
The failure wasn't the Chinese rod. Boosted D series. Installed and never checked. Didn't even plastigage it. Bolted it together and ran it.
Just posting that the auto correct title is pretty funny.
Not sure what a Dingrod is, let alone a Pee Dingrod from Max.
alfadriver said:
Just posting that the auto correct title is pretty funny.
Not sure what a Dingrod is, let alone a Pee Dingrod from Max.
That wasn't autocorrect. That was manualuncorrect.
For whatever reason, the brand in question apparently elected to market themselves as Maxpeedingrods. Had they included an 'S', they would been Maxspeedingrods, which almost makes sense. But they didn't. So we are bound by the laws of bathroom humor to refer to the brand as Max Pee Dingrods.
ShawnG
MegaDork
3/23/24 12:21 a.m.
Is this one of those 7A-FE bottom end, 4A-GE top end, Porsche timing belt, frankenmotors?
oldeskewltoy said:
https://www.mrpltd.co.nz/product/7a-h-beam-conrods/
Mmmm-hmm. The exchange rate is looking pretty good right now. They look identical to Dingrods, to the point where I wonder whether they are based on the same forgings, but maybe Manon has an arrangement with the actual manufacturer to get the cream of the crop. Who knows? I'm not in a position to doubt MRP.
ShawnG said:
Is this one of those 7A-FE bottom end, 4A-GE top end, Porsche timing belt, frankenmotors?
That's exactly what it is, a 7A-GE. They had a bad reputation for a long time that I think was partly due to hasty assembly by, uh, unseasoned builders who didn't take the time to swap in 4A-GE pistons or sort out the inherently wonky cam timing, and partly due to internet experts who were certain that the entire rotating assembly would self-destruct because it doesn't have all the same stuff a 4A-GE has. But this one runs pretty good and has put smiles on many faces.
DarkMonohue said:
oldeskewltoy said:
https://www.mrpltd.co.nz/product/7a-h-beam-conrods/
Mmmm-hmm. The exchange rate is looking pretty good right now. They look identical to Dingrods, to the point where I wonder whether they are based on the same forgings, but maybe Manon has an arrangement with the actual manufacturer to get the cream of the crop. Who knows? I'm not in a position to doubt MRP.
Any set of rods (4) under $1000 is most likely manufactured in China, or other low cost supplier. The key to quality in this line is the finishing process, and the use of real, or imitation ARP hardware.
Great example are Molnar rods. Manufactured in China, but finished in the USA to a tolerance of 0.0001", and using only genuine ARP hardware.
In reply to DarkMonohue :
TIL. Nice, and funny!
In reply to oldeskewltoy :
Exactly. I have used molnar with great success in the past. They average about $115 a rod and have withstood everything I have ever done. I have a new set waiting on a turbo mivec build I am working on.
Opti said:
In the SBC pretty much all of the mid tier stuff is forged in China and then sometimes final machining is done here.
EVERYTHING forged is done in China. The shops don't exist anymore in the US. We tried. Nobody does it in the US anymore.
In a previous life, I ran a lathe to clean up some Chinese forgings, which was enough to meet the legal definition of "Made in the USA". With offshore "raw materials".
In reply to oldeskewltoy and bmw88rider :
Molnar has been suggested in an offline conversation, but I'd forgotten the name. Thanks for the reminder. IIRC they once listed a rod for this application but no longer do. Very much worth a phone call or email.
$115 per rod is ~$100 a set more than Max Pee branded units on the auction site. That's not much for the peace of mind that someone who knows what to look for has given them a once-over.
DarkMonohue said:
In reply to oldeskewltoy and bmw88rider :
Molnar has been suggested in an offline conversation, but I'd forgotten the name. Thanks for the reminder. IIRC they once listed a rod for this application but no longer do. Very much worth a phone call or email.
$115 per rod is ~$100 a set more than Max Pee branded units on the auction site. That's not much for the peace of mind that someone who knows what to look for has given them a once-over.
I spoke to Tom Molnar... the did once have a 7AF rod.... no longer available.
