Big turbo, little turbo and engine capabilities

[Lee P]

The first limit in the stock block is usually the rod bolts. These become a problem over 750hp and when revving too high.

 

If you run arp rod bolts with a large turbo and keep the egt's down I don't see why you couldn't run more. How much more reliably I don't know, that will have to be tested.

[hodge]

The first limit in the stock block is usually the rod bolts. These become a problem over 750hp and when revving too high.

 

If you run arp rod bolts with a large turbo and keep the egt's down I don't see why you couldn't run more. How much more reliably I don't know, that will have to be tested.

 

 

 

I guess we've found a guinea pig Lee.

I'm thinking 800hp is a good marker to to aim at, pushing boundaries a little but not being greedy

[Paul Whiffin]

If I reduce the size of the A/R to 1.01 Paul what sort of difference would I see to full boost within the rev range.

 

I dropped mine to 1.01 and it was about 200rpm approx. small but noticeable difference. I've still got the housing somewhere if you need to try one.

[Paul Whiffin]

The first limit in the stock block is usually the rod bolts. These become a problem over 750hp and when revving too high.

 

If you run arp rod bolts with a large turbo and keep the egt's down I don't see why you couldn't run more. How much more reliably I don't know, that will have to be tested.

 

I ran 821bhp on a stock engine back in 2004 with 1.9 bar revving to 7500rpm, that was using on the race track to, never had a problem with it. Go for it mate, what you got to lose apart from an engine, turbo, oil cooler,etc!

[hodge]

Id go dual valve springs then up the rev limit to something like 7800-7900 should be plenty of revs for that turbo.

 

I made the mistake of going single supertech valve springs in my last build and we think i was getting valve flutter, my power stopped dead at about 6500rpm where it should still have been climbing fast to my 8200rpm rev limit, running a to light a spring on a big turbo/big rev 2jz wont let the bucket follow the profile and performance is compromised.

 

http://i30.photobucket.com/albums/c338/jamie450x/894bhp002.jpg

 

Its all being changed now and if my power keeps rising this time as it should i hope to hit the 1000bhp mark with ease.

 

Any advice on what make of spring to go for or they all pretty much the same. I've never really looked into this to be honest.

[JamieP]

I stayed supertech.

[Paul Whiffin]

paul, on your bw turbo kit i spoke to you about when will the power come in at full boost? what revs roughly?

 

About 4000rpm mate, that turbo might be overkill for what you need though. You could go smaller on the turbo with an S362 like we did with Ad's car, he made 560bhp on a completely stock engine with full boost at 3600rpm, seriously fast spool up that is. It'll make an easy 600bhp with cams to.

[Paul Whiffin]

Any advice on what make of spring to go for or they all pretty much the same. I've never really looked into this to be honest.

 

Supertech or Ferrea dual springs, either or.

[hodge]

I dropped mine to 1.01 and it was about 200rpm approx. small but noticeable difference. I've still got the housing somewhere if you need to try one.

 

Cheers Paul. I'll be in touch about that mate.

 

I ran 821bhp on a stock engine back in 2004 with 1.9 bar revving to 7500rpm, that was using on the race track to, never had a problem with it. Go for it mate, what you got to lose apart from an engine, turbo, oil cooler,etc!

 

Seems you put it like that lol, why not.

[hodge]

I've just priced up the ferrea and supertech duel spring kits and the Supertech is half the price. Supertech it is then.

I'll get solaris and the car running 1st then look into swapping these. There's a few other bits I'm going to do once I've got it running aswell.

I will be changing the catback part of the exhaust for full 4" and also adding another Bosch 044 into the tank. But again I want the car running 1st just to iron out any issues there MAY be with the build.

[Paul Whiffin]

I've just priced up the ferrea and supertech duel spring kits and the Supertech is half the price. Supertech it is then.

I'll get solaris and the car running 1st then look into swapping these. There's a few other bits I'm going to do once I've got it running aswell.

I will be changing the catback part of the exhaust for full 4" and also adding another Bosch 044 into the tank. But again I want the car running 1st just to iron out any issues there MAY be with the build.

 

Supertech is normally a little bit more if anything, you sure about that? I keep the Supertechs in stock anyway.

[hodge]

Can you p.m me a price for both kits please Paul. I wouldn't be wanting them until the new year but justvto give me an idea of the cost.

Thanks mate.

[TLicense]

That's going to be Ryans jobs mate. I'll be leaving it totally in his hands. I trust whatever he thinks best.

 

With absolutely no offence to Ryan, and I know he won't see it as such, what max rev limit you run should be specified by whoever built the engine, not the mapper. Whether it's worth running up as high as it can to get the max power can be determined by the mapper.

 

The first limit in the stock block is usually the rod bolts. These become a problem over 750hp and when revving too high.

 

If you run arp rod bolts with a large turbo and keep the egt's down I don't see why you couldn't run more. How much more reliably I don't know, that will have to be tested.

 

Depending on the assembly methods you used, it's possible to calculate the stresses that will be generated by the engine over a stock set-up.

[TLicense]

Ideally the springs will be matched to your camshafts.

HKS only recommend using the OEM springs, but then they also recommend a max of 6750 rpm.

[Nic]

Ideally the springs will be matched to your camshafts.

HKS only recommend using the OEM springs, but then they also recommend a max of 6750 rpm.

 

Where have you read that Tony? They spec their cams for the with the VVTi which I thought rev to 7200rpm as standard. They mention their higher performance HKS valve springs for certain applications, but they don't make them for the 2JZ.

 

HKS high performance camshafts are CAD designed to optimize torque and horsepower over the widest possible power band. Each camshaft application is offered in multiple profiles, each with their own lift & duration characteristics to suit various levels of tuning. Lower profiles offer substantial gains in power and a broad useable power band with little compromise in drivability. Higher profiles offer greater increases in power, but are tailored for the higher RPM range and racing applications.

 

HKS camshafts are not reground OEM units; they are machined from new billet cores which are constructed from a high nickel content iron alloy. By manufacturing all camshafts from billet cores, HKS is able to produce camshafts that equal or exceed the quality of the OEM units they are designed to replace. HKS camshafts are direct replacements and are designed to be compatible with the factory valve train components. However, due to the higher profile of HKS camshafts, HKS high performance valve springs are highly recommended, and required in certain applications.

[TLicense]

The max RPM is stated on the cam cards.

 

I e-mailed HKS when I was looking at sorting my head over the summer and they mentioned that all of the camshafts for the 2JZ were what they called "stage 1" and were only suited to the OEM springs. I guess that's why they don't make the higher performance springs for the 2JZ.

[hodge]

With absolutely no offence to Ryan, and I know he won't see it as such, what max rev limit you run should be specified by whoever built the engine, not the mapper..

 

Well I built the engine lol and to be honest I'll feel safer leaving it to Ryan lol.

[TLicense]

OK.....

Although I don't know how Ryan is supposed to know how for example you've assembled the con-rods, which is a primary factor on whether it'll take revs or not.

 

I could for instance build an engine that will be fully in tolerance but by changing how it's assembled will let go at 8000 RPM, or 10,000+ RPM. How Ryan is supposed to be able to guess that I don't know.

[hodge]

OK.....

Although I don't know how Ryan is supposed to know how for example you've assembled the con-rods, which is a primary factor on whether it'll take revs or not.

 

I could for instance build an engine that will be fully in tolerance but by changing how it's assembled will let go at 8000 RPM, or 10,000+ RPM. How Ryan is supposed to be able to guess that I don't know.

 

Forgive my ignorance but what do you mean by how I assembled the rods and how could this effect the rev limit. Thought they could only be assembled 1 way.

[jagman]

This posts prompts about 15 different aspects in one go , best take each aspect one at a time , and there will be no definitive answer as no data or testing has ever been done - (except toyota)

Rods for example can easily take the stress and strain , but there is no cyclic fatigue data , and they are subject to bearing quality and tolerance,oil conditions, det ,rod bolts,balance and harmonics .

The rate of stress is less important than the maximum stress and rpm , they are already under stress many times a second , and the elastic qualities less important than the bearings and oil and balance

The largest stress will be det and shock from it

[TLicense]

Forgive my ignorance but what do you mean by how I assembled the rods and how could this effect the rev limit. Thought they could only be assembled 1 way.

 

They can only be assembled in one orientation, but there's lots of other factors:-

 

What was the final weight of your pistons and rods?

What is the yield strength, younds modulus and ultimate tensile strength of the material the rod bolts are made from?

What is the core diameter of the bolt?

What is the pitch of the bolt?

Did you use lube on the rod bolts?

What is the lube coefficient?

Exactly what bolt stretch did you tighten the bolts to?

Exactly what bearing oil clearance did you end up with?

What bearing crush did you allow for?

What tolerance did you balance the rotating and reciprocating assemblies to?

 

Jagman is quite correct that det will create the most stress, but that's where Ryan steps in. (Making sure the car doesn't det). However, if Ryan was mapping an engine that was built to take 8000 RPM, or if he was mapping an engine that was built to take 18,000 RPM, his process would essentially be the same. Making sure that the engine can take the revs is the responsibility of the engine builder.

[Rob_Mitchell]

was typing exactly the same, beat me to it

[SupraShaun]

was typing exactly the same, beat me to it

 

[Nic]

The max RPM is stated on the cam cards.

 

I e-mailed HKS when I was looking at sorting my head over the summer and they mentioned that all of the camshafts for the 2JZ were what they called "stage 1" and were only suited to the OEM springs. I guess that's why they don't make the higher performance springs for the 2JZ.

 

Thanks Tony, wasn't aware of that

[hodge]

They can only be assembled in one orientation, but there's lots of other factors:-

 

What was the final weight of your pistons and rods?

What is the yield strength, younds modulus and ultimate tensile strength of the material the rod bolts are made from?

What is the core diameter of the bolt?

What is the pitch of the bolt?

Did you use lube on the rod bolts?

What is the lube coefficient?

Exactly what bolt stretch did you tighten the bolts to?

Exactly what bearing oil clearance did you end up with?

What bearing crush did you allow for?

What tolerance did you balance the rotating and reciprocating assemblies to?

 

Jagman is quite correct that det will create the most stress, but that's where Ryan steps in. (Making sure the car doesn't det). However, if Ryan was mapping an engine that was built to take 8000 RPM, or if he was mapping an engine that was built to take 18,000 RPM, his process would essentially be the same. Making sure that the engine can take the revs is the responsibility of the engine builder.

 

These are stock robs and pistons Tony. I replaced them back into the engine after I stripped it. The only updated parts I used were all bolts/studs were replaced with ARP's an bearings were replaced ACL race bearings. I refitted the rods and pistons because everything was still in perfect order and the bores were still perfectly round no ovality what so ever. Everything was coated with engine assembly lub as I put it all together, all gaskets, seals and pumps were brand new also.